当前期刊: Journal of Coordination Chemistry Go to current issue    加入关注   
显示样式:        排序: 导出
  • Unusual coordination behavior by a hydroxypyridine/pyridone ligand: Synthesis and structure of [(2-bromo-4-hydroxypyridine)2(2-bromo-1(H)-4-pyridone)2copper(II)] perchlorate • 2(2-bromo-4-hydroxypyridine) • 2(2-bromo-1(H)-4-pyridone)
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-18
    Jeffrey C. Monroe; Mark M. Turnbull

    The synthesis and structure of [Cu(2-Br-4-HOpy)2(2-Br-4-pyone)2](ClO4)2 • 2(2-Br-4-HOpy) • 2(2-Br-4-pyone) is reported [2-Br-4-HOpy = 2-bromo-4-hydroxypyridine; 2-Br-4-pyone = 2-bromo-(1H)4-pyridone]. The compound forms as a co-crystal in the triclinic P-1 space group with four-coordinate Cu(II) ions and perchlorate geganions interacting with both the hydroxypyridine and pyridone forms of the organic molecule through hydrogen and halogen bonding. The coordination complex exhibits the unusual coordination motif of having both the hydroxypyridine and pyridone tautomers of the ligand coordinated to the same metal ion. The isolation of the Cu complex by the organic groups suggests an absence of magnetic exchange within the sample which is confirmed by variable temperature magnetization measurements and EPR data.

  • Design, structural, C–H….H–C supramolecular interactions and computational investigations of Cd(N∩N″)X2 complexes based on an asymmetrical 1,2-diamine ligand: physicochemical and thermal analysis
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-12-02
    Ismail Warad; Khaled Alkanad; Mohammed Suleiman; Karthik Kumara; Anas Al-Ali; Yasser H. E. Mohammed; Neartur K. Lokanath; Abdelkader Zarrouk

    Complexes [N∩N″CdX2] (X = Cl (1), I (2) and N∩N″ is N1,N1,N2-triethylethane-1,2-diamine) are reported. The desired complexes were prepared under identical synthetic conditions and characterized by ESI-MS, UV-vis, CHN-elemental analyses, 1H-NMR and FT-IR. The structure of 2 has been confirmed by XRD studies, wherein N∩N″CdI2 complex crystallized in the monoclinic space group P21/n with a = 9.245(8) Å, b = 15.190(12) Å, c = 10.905(9) Å, V = 1491(2) Å3, and Z = 4. Distorted tetrahedral geometry around the Cd(II), constructed from 2N and 2I, was confirmed by single crystal XRD. Only C–H….H–C supramolecular interactions have been detected in 2. Hirshfeld surface analysis (HSA) reflected presence of weak H….H noncovalent supramolecular interactions and presence of no H….I bonds are consistent with the experimental XRD-result. Mulliken population charge and molecular electrostatic potential (MEP) calculations for N∩N″CdI2 were carried out to support the XRD-result. The computed electronic parameters B3LYP-IR, frontier molecular orbital (FMO), time-dependent self-consistent field/density functional theory (TD-SCF/DFT), and the global reactivity descriptors (GRD) quantum numbers were estimated and compared to the experimental data. Thermal stability studies of the N∩N″CdI2 complex were carried out via TGA/DTG from 0 to 800 °C in open atmosphere.

  • Pd(0) immobilized on Fe3O4@AHBA: an efficient magnetically separable heterogeneous nanocatalyst for C–C coupling reactions
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-11
    Tonmoy Chakraborty; Abani Sarkar; Tanmay Chattopadhyay

    We have developed a new method to synthesize magnetically separable Fe3O4@AHBA@Pd(0) (AHBA = 3-amino-4-hydroxybenzoic acid) heterogeneous nanocatalyst via anchoring of palladium(0) on the surface of AHBA-coated Fe3O4 nanoparticles. The synthesized nanocatalyst was characterized by FT-IR, PXRD, ICP, XPS, FESEM, EDX, TEM, TGA, BET, and FT-RAMAN analysis. X-ray photoelectron spectroscopy (XPS) indicated the presence of Pd(0) on the surface of Fe3O4@AHBA. BET analysis exhibits high surface area of the prepared nanocatalyst with catalytic activity toward Heck coupling reactions with high turnover frequency (TOF) at 60 °C in water–acetonitrile within 2 h. The nanocatalyst can be easily recovered from the reaction mixture by using an external magnet and recycled six times without significant decrease in its catalytic activity. All the isolated products are obtained as solids or oils, fully characterized by 1H-NMR spectroscopy.

  • Development of multi-metallic complexes using metal-salen complexes as building blocks
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-12-28
    Ipsita Mondal; Shouvik Chattopadhyay

    Metal-salen complexes have been widely used in inorganic chemistry to synthesize polynuclear complexes. This review highlights the synthetic strategy of multi-metallic complexes using metal-salen complexes as building blocks and structures of the resulting complexes. Three different processes have been used to prepare multi-metallic complexes using metal-salen complexes: (i) use of metal-salen complexes as metalloligands, (ii) self-assembly processes involving [M(salen)] complexes and various cyanaometallates and (iii) use of salen-type compartmental ligands. Complexes formed by these methods are included in the review. X-ray single crystal diffraction analysis confirmed the structures of these complexes. The properties of these complexes are also briefly discussed. This review will be of interest to researchers and synthetic chemists for synthetic strategy of homo- and heterometallic polynuclear complexes using salen-type Schiff bases.

  • Copper(I) π-coordination compounds with allyl derivatives of disubstituted pseudothiohydantoin: synthesis, structure investigation and nonlinear optical features
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-15
    Andrii A. Fedorchuk; Yurii Slyvka; Vasyl Kinzhybalo; Iwan Kityk; Jarosław Jędryka; Katarzyna Ozga; Marian Mys`kiv

    The present work is directed towards preparation by means of alternating current electrochemical synthesis, structural, and optical property characterization of Cu(I) π-coordination compounds [Cu(papt)NO3] (1), [Cu2(papt)2Cl2] (2), [Cu2(papt)2Br2] (3), [Cu2(eapt)2Cl2] (4), and [Cu2(eapt)2Br2] (5) with disubstituted pseudothiohydantoins, (2Z)-2-(phenylimino)-3-allyl-1,3-thiazolidin-4-one (papt) and (2Z)-2-[(2-hydroxyethyl)imino]-3-allyl-1,3-thiazolidin-4-one (eapt). All coordination compounds crystallize in the centrosymmetric monoclinic P21/n space group, 2 and 3, as well as 4 and 5 are isostructural to each other. Cu(I) in all the structures have trigonal–pyramidal environment formed by N-imino and allyl C = C double bond of the chelate organic ligand and two oxygens of NO3– in 1 or two halides in 2–5. Crystal packing of 2 and 4 were analyzed using energy framework computational analysis to examine differences in crystal structures of papt- and eapt-based coordination compounds, which could be explained by the difference in weak interactions of phenyl and 2-hydroxyethyl groups. The third-order nonlinear optical features for 1 and 2 are studied at 1064 nm generated by a nanosecond pulsed Nd:YAG laser.

  • Synthesis and characterization of a manganese(III) schiff base complex and exploration of Br···Br interaction in the solid state structure of the complex
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-19
    Ipsita Mondal; Kousik Ghosh; Antonio Franconetti; Antonio Frontera; Sudipta Chatterjee; Shouvik Chattopadhyay

    A mononuclear manganese(III) complex, [MnL(CH3OH)(H2O)]ClO4, has been synthesized and structurally characterized {H2L = N,N'-bis(5-bromo-3-methoxysalicylidene)2,2-dimethyl-1,3-propanediamine}. The energetic features of significant supramolecular interactions present in the complex, i.e. Br···Br, hydrogen-bonding and π···π stacking interactions, have been calculated using DFT calculations and further corroborated with NCI plot index computational tool. Catalase mimicking activity (catalytic decomposition of hydrogen peroxide into oxygen and water) of the complex has been investigated. The complex catalyzes the decomposition of hydrogen peroxide effectively in solution. The efficiency of the complex toward catalytic decomposition of hydrogen peroxide is related to its structure.

  • Synthesis, characterization and single crystal X-ray structures of oxidovanadium(V) complexes derived from N’-(2-hydroxy-3-methoxybenzylidene)-3,5-dimethoxybenzohydrazide with antibacterial activity
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-22
    Cui-Lin Zhang; Xiao-Yang Qiu; Shu-Juan Liu

    A new oxidovanadium(V) complex, [VOL(OCH3)(CH3OH)] (1), was prepared from N’-(2-hydroxy-3-methoxybenzylidene)-3,5-dimethoxybenzohydrazide (H2L). Reaction of 1 with ethyl maltol (HL') in methanol afforded the new oxidovanadium(V) complex, [VOLL'] (2). The complexes were characterized by IR, UV and 1H NMR spectra. Structures of the complexes were further confirmed by single crystal X-ray determination. The V ions in the complexes are octahedral. The hydrazone ligands coordinate to V through the phenolate O, imino N, and enolate O. The ethyl maltolate ligand coordinates to V through the carbonyl and hydroxy oxygens. Both complexes show effective antibacterial activity against B. subtilis, S. aureus and P. aeruginosa. Thermogravimetric analysis was also performed.

  • Direct arylation of heteroarenes by PEPPSI-type palladium–NHC complexes and representative quantum chemical calculations for the compound which the structure was determined by X-ray crystallography
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-23
    Neslihan Şahin; Goncagül Serdaroğlu; Serpil Demir Düşünceli; Muhammad Navaz Tahir; Cengiz Arıcı; İsmail Özdemir

    In this study, we synthesized five new PEPPSI-type Pd-NHC complexes with high yields around 78–83%. The structures of all complexes were characterized by FT-IR, 1H NMR, and 13C{1H} NMR spectroscopies. Further, the structure of 2c was determined by X-ray crystallography. The single-crystal structure of 2c shows that coordination geometry around Pd is distorted square planar. The Pd-NHC complexes were efficient catalysts for the direct C5-arylation of 2-n-butylthiazole, 2-n-butylfuran, and 2-n-butylthiophene with various aryl-bromides and showed high catalytic activity for arylation reaction using only 1 mol% catalyst loading at 130 °C for 1 h. The conversions for substrates containing electron-withdrawing groups were higher than for substituents containing electron-donating groups. In order to evaluate the catalytic activity of the complexes, representative electronic and spectroscopic simulations by DFT method have been performed for 2c. NBO analysis has revealed that the strongest interaction contributing to the lowering of the molecular stabilization energy for 2c is predicted as π(C11-N27) → π*(N26-C28) with E(2) = 73.93 kcal mol−1. In addition, FMO analysis has implied that 2c is more chemically reactive because of its lower energy gap value. According to the other quantum chemical parameters, 2c is softer, better electrophile and has more charge-transfer capability than 1c.

  • A Pr3+-coordination polymer as an adsorbent for neutral red
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-12
    Ling Qin; Qing-He Liu; Li Wang; Xin-Ru Ma; Hao Shen; Yun-Yun Li; Xi-Xiu Shi; Yang Wu; Juan Li

    A luminescent Pr3+-coordination polymer based on functional linear tetrazole-carboxylic acid and an auxiliary ligand, {[Pr(TBCA)(BPA)·2H2O]}n (1) (HTBCA = 4′-(1H-tetrazol-5-yl)-biphenyl-4-carboxylic acid, H2BPA = 2,2′-biphenyldicarboxylic acid), has been solvothermally synthesized and characterized by single crystal XRD, infrared spectroscopy, elemental analysis, and powder X-ray diffraction. Structural analysis reveals that 1 is a 1D coordination polymer with chains approximately parallel to the a-axis, linked by H-bonding interactions to form a 3-D arrangement. The uptake results for six dyes with different size and different charges revealed that 1 can adsorb neutral red and hardly adsorb the other dyes.

  • Preparation of a dimer from self-complementary of cobalt(III) complex with dissymmetric compartmental ligand and study of the interaction of the complex with DNA and BSA
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-27
    Leila Zarei; Zahra Asadi; Erika Samolova; Michal Dusek

    Synthesis of [Co(L)(H2O)(HOCN(CH3)2)](ClO4) (where L denotes N,N′-bis(3-methoxysalicylidene)-1,2-diaminopropane) was reported. The complex was characterized by 1H NMR, elemental analysis, IR and UV–vis spectroscopy and the structural features have been solved by X-ray crystallography. The crystal structure analysis showed that the arrangement around cobalt atom is octahedral with two imine nitrogen atoms (N1 and N2) and two oxygen atoms of hydroxyl groups (O2 and O3) at equatorial positions and an aqua ligand and a DMF ligand at the axial positions. The hydrogen-bonding interactions between coordinated H2O and phenoxo/methoxy oxygens connect the complex molecules in dimers. Interaction of the complex with FS-DNA and protein (BSA) was explored by fluorescence and absorption spectroscopy, viscosity measurements, circular dichroism (CD), cyclic voltammetry (CV) and agarose gel electrophoresis. According to the Kb value about 103, the complex is moderately bound to DNA. The complex interacts with protein (BSA) by both static and dynamic quenching. According to cleavage experiment, the complex destroys annular DNA and causes double strand break. Molecular docking was done to achieve detailed binding information of the complex to DNA and BSA. Moreover, cytotoxic activity was evaluated by MTT assay. The complex has low toxicity against the MCF-7 and LNCaP cancer cells.

  • Synthesis and spectral characterization of metal complexes of Schiff base derived from indole-3-carboxaldehyde and L-histidine as potent biocides
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-27
    R. Reshma; R. Selwin Joseyphus; Arish Dasan; Liji John

    This research work presents the structural features and biological activities of a novel series of Mn/Fe/Co/Ni/Cu/Zn(II)-(indal-L-his) complexes obtained from indole-3-carboxaldehyde (indal) and L-histidine (L-his). The prepared compounds were characterized by elemental analysis, molar conductivity, magnetic, IR, UV–vis, 1H NMR, mass and ESR spectroscopies, powder XRD and TGA studies. Electronic spectra and magnetic moment data suggest an octahedral geometry for [Mn(II)-(indal-L-his)2(H2O)2] and [Fe(II)-(indal-L-his)2(H2O)2], tetrahedral geometry for [Co(II)-(indal-L-his)2] and [Zn(II)-(indal-L-his)2] and square planar geometry were assigned for [Ni(II)-(indal-L-his)2] and [Cu(II)-(indal-L-his)2]. The photocatalytic efficiency was explored for the synthesized compounds. In vitro antimicrobial activity of synthesized compounds was analyzed against some selected Gram-positive and Gram-negative bacterial and fungal species by disc diffusion technique. The compounds have shown to reveal excellent antibacterial and antifungal activity.

  • Synthesis and evaluation of Zn(II) dithiocarbamate complexes as potential antibacterial, antibiofilm, and antitumor agents
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-22
    Vinay Kumar Maurya; Ashish Kumar Singh; Ravi Pratap Singh; Shivangi Yadav; Krishna Kumar; Pradyot Prakash; Lal Bahadur Prasad

    Four complexes having the formula [Zn(L)2] [L1 = (C18H20NS2–), N-(4-isopropyl-benzyl)-(benzyl)-dithiocarbamate], [L2 = (C10H12NS2–), N-(benzyl)-(ethyl)-dithiocarbamate], [L3 = (C19H22ONS2–), N-(4-isopropyl-benzyl)-(4-methoxy-benzyl)-dithiocarbamate], and [L4 = (C16H16NS2–), N-(benzyl)-(4-methyl-benzyl)-dithiocarbamate] have been contemplated, synthesized, and characterized by elemental analysis and IR, 1H, 13C NMR and UV–visible absorption spectra. All Zn(II) complexes have similar geometry and coordination number. Complex A2 (with ligand L2) crystallizes in triclinic system with space group P-1 having distorted square pyramidal geometry which was stabilized by weak C–H···π and C–H···S intramolecular interactions. The antibacterial, antibiofilm, and antitumor activities of the complexes have been screened and A2 and A3 showed their prominence. Interestingly, both A2 and A3 showed more killing potential against multi-drug resistant gram-positive isolates with MIC indices of 16 μg mL−1 and 16 μg mL−1, respectively, against both MRSA and MSSA, while the antitumor agent A3 showed its prominence with GI50 and LC50 41.15 and 133.73 µg mL−1, respectively.

  • Cu(II)-sulfamethazine complex with N-(2-hydroxyethyl)-ethylenediamine: synthesis, spectroscopic, structural characterization and antimicrobial activity
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-29
    Filiz Öztürk; Tuğba Aycan; Nilgün Özdemir

    A five-coordinate monomeric Cu(II) complex, 2([Cu(hydeten)2]·smz2)·na·5H2O (Hsmz: sulfamethazine, hydeten: N-(2-hydroxyethyl)-ethylenediamine and na; nicotinamide), has been synthesized and characterized by elemental analysis, X-ray diffraction techniques, IR, EPR and UV-vis spectroscopies. In the X-ray structural analysis, the copper atom is coordinated to two hydeten ligands, one of which is a triple and the other is a bilateral. Thus, it has two five-coordinate copper central cations which exhibit a distorted square-pyramidal geometry (τ = 0.23). The charge equivalence of the molecule is provided by the four sulfamethazine ligands which are deprotonated. The powder EPR spectra of the Cu(II) complex at room temperature and in liquid nitrogen were recorded. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated and indicated the presence of the unpaired electron in the dx2-y2 orbital. Antimicrobial activity studies of the synthesized compound were investigated against S. aureus, B. subtilis, P. aeruginosa, E. coli, C. albicans and A. flavus by using the microdilution method.

  • Synthesis, spectroscopic characterization, DFT calculations, and antimicrobial activities of N-arylsalicylaldiminate derivatives of diorganotin(IV)
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-12-28
    Raj Kumar Dubey; Avadhesh Pratap Singh; Nitesh Jaiswal; Divya Pratap Singh; Meenakshi; Ajeet Kumar Kushwaha; Manoj Kumar; Afreen Anjum

    Equimolar reaction of di-n-butyltin(IV) complexes of bidentate Schiff bases of the type [(n-Bu)2Sn(sb)Cl] with sodium salt of mono-functional bidentate ligands in THF-benzene solution afforded structurally interesting complexes of the type [(n-Bu)2Sn(sb)(L)] (1–6) [where sbH = Schiff bases: N-salicylidene-2-aminopyridine (sapH) I, N-salicylidene-2-methylaminobenzene (o-smabH) II, and N-salicylidene-4-methylaminobenzene (p-smabH) III; LH = mono-functional bidentate ligands, acetylacetone (acacH), ethanolamine (eaH)]. All these colored solid complexes were soluble in common organic solvents and characterized by elemental (C, H, N, and Sn) analysis, spectroscopic techniques [IR, (1H, 13C, and 119Sn) NMR] and mass spectrometry. Thermogravimetric analysis of complexes shows thermal behavior and stability of complexes. Computational studies of the synthesized Schiff bases and their organotin(IV) complexes were carried out using DFT which validate the structure of complexes proposed on the basis of spectroscopic data. The mixed-ligand complexes of diorganotin(IV) and Schiff bases were screened for their antibacterial and antifungal activities.

  • Rutheniumethynyl-triarylamine mixed-valence conjugated system: syntheses, (spectro-)electrochemistry, and theoretical calculations
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-28
    YA-Ping Ou; Yuxuan Hu; Meng Xu; Aihui Wang; Sheng Hua Liu

    We describe the synthesis and characterization of triarylamine ethynyl ruthenium conjugate (4-OMeC6H4)2N-{C6H4-4-C≡C-RuCp* (dppe)}, 3. Its electronic and spectroscopy properties are investigated by anodic voltammetry, IR and UV–vis–NIR spectroelectrochemistry, and density functional theory (DFT) calculations. Results indicate that 3 undergoes two well-defined single-electron redox processes and that the RuII/III process occurs prior to the N0/+ process as supported by IR spectra ν(C≡C) band changes from 3 to 3+ (Δν = 129 cm−1) and spin-density distribution calculations of 3+. TDDFT calculations further reveal the NIR characteristic bands of singly oxidized 3+ from experimental spectroscopic absorptions, and we observe NAr2→Ru charge transfer mixed with Ru-C≡C→phenyl bridge charge-transfer.

  • Schiff base complexes of Mo(VI) immobilized on functionalized graphene oxide nano-sheets for the catalytic epoxidation of alkenes
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-18
    Behnam Rezazadeh; Ali Reza Pourali; Alireza Banaei; Hossein Behniafar

    Mo(VI) tetradentate Schiff base complexes were covalently immobilized onto chemically functionalized graphene oxide (GO) using 3-(tri-methoxysilyl) propylamine as a coupler. The resulting heterogeneous catalysts have been characterized by FTIR, DRS, XRD, SEM, TGA, and atomic absorption spectroscopy (AAS). These catalysts were applied in epoxidation of cyclooctene and other olefins. The catalytic procedures with all catalysts were optimized for different parameters such as oxidant, solvent and temperature. Recycling results indicated that the catalysts were highly stable and maintained activity and selectivity even after being used for five cycles.

  • Polyoxometalate based hybrid chiral material: Synthesis, characterizations and aerobic asymmetric oxidation reaction
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-20
    Anjali Patel; Ketan Patel

    A new hybrid chiral material, comprising Keggin type mono ruthenium substituted phosphotungstate (PW11Ru) and chiral (R-(-)-1-cyclohexylethylamine (Cy)), was synthesized in an aqueous medium by simple ligand substitution. The bonding was confirmed by FT-IR, multinuclear NMR (31P, 13C and 15N), while the chirality was confirmed by CD spectroscopy and a polarimeter. The study reveals the attachment of Cy and PW11Ru through N → Ru bond. An attempt was made to use the synthesized material as a heterogeneous catalyst for carrying out aerobic asymmetric oxidation of styrene and found that only 0.001 mg (7.9 × 10−6 mmol) of Cy was sufficient to achieve very high TON.

  • Correction
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-30

    (2019). Correction. Journal of Coordination Chemistry: Vol. 72, No. 19-21, pp. 3444-3444.

  • Heavy metal complexes of 4-chlorodipicolinic acid - structural, spectral and thermal correlations
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-12
    Z. Vargová, M. Almáši, R. Gyepes, R. Vetráková

    The ligand, 4-chloro-2,6-dipicolinic acid (H2PDA-Cl), and its two heavy metal complexes, [Ag(HDPA-Cl)(H2DPA-Cl)·2H2O] (1) and {[Cd(μ2-H2O)(H2O)(PDA-Cl)]}n (2), were prepared and then characterized by single-crystal X-ray diffraction. In addition, spectral and thermal correlations with structural results complete their solid-state description and facilitate complex 3 ([Pb(DPA-Cl)]) composition determinations. Complex 1 crystallizes in a monoclinic space group C2/c and each DPA-Cl ligand is tridentate to Ag(I) through the pyridine N and two monodentate carboxyl O atoms. The carboxy group with carbonyl C1 is semideprotonated and forms a symmetric hydrogen bond with a carboxy group of a neighboring complex. Complex 2 crystallizes in a triclinic lattice with space group P . The Cd(II) ions are seven-coordinate and the coordination polyhedra can be described as a distorted pentagonal bipyramid. IR data are consistent with monodentate coordination of the carboxylate to Ag(I), Cd(II), and Pb(II) and observed wavenumber shifts confirm PDA-Cl ligand coordination to Pb(II) in 3. Thermal stability of anhydrous complexes indicates the metal–ligand interactions. The thermal stability of prepared compounds is reflected by the strength of interaction between metal–ligand and hydrogen bonds.

  • Macrocyclic copper(II) complexes containing diazacyclam-based ligand: spectral, structural and docking studies
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-06
    Zahra Mardani, Keyvan Moeini, Majid Darroudi, Cameron Carpenter-Warren, Alexandra M. Z. Slawin, J. Derek Woollins

    The macrocyclic copper complex, [Cu(ACE)(NO3)2] (ACE = 1,3,6,10,12,15-hexaazatricyclo[,10]eicosane), was synthesized by template condensation from a mixture of N1-(2-aminoethyl)-1,3-diaminopropane, formaldehyde and copper(II) nitrate. Replacement of the nitrate with thiocyanato and azido ligands gives [Cu(ACE)NSC]NSC (2) and the 1D-coordination polymer, [Cu(ACE)(μ-N3)]n[N3]n (3), respectively. Complex 1, [Cu(ACE)(NO3)]NO3, is an intermediate product in which one of the nitrate ions is separated from its parent molecule. The formation of 1 allowed us to conclude that the mechanism of ion exchange in the parent molecule is similar to SN1. These complexes have been characterized by FT-IR spectroscopy and X-ray crystallography. In the crystal structures of 1 and 2, the copper(II) ion has a distorted square pyramidal geometry in which the N4-donor ACE ligand lies on the equatorial plane and other ligand occupies the axial position. The copper(II) ion in 3 has an octahedral geometry, coordinating to one ACE ligand in the equatorial plane and two N-donor bridging azido groups in the axial positions. In all structures, owing to the Jahn-Teller effect, the coordinated bond length of the axial position is longer than the equatorial ones. The ability of the ACE ligand and its complexes 1 and 2, along with their analogues, to interact with 10 selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B-DNA) was investigated by docking calculations and compared with that of doxorubicin.

  • Syntheses, structures and properties of two mononuclear copper(I) complexes with N-heterocyclic ligands
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-10
    Yao Qu, Cong Wang, Kun Zhao, Yancong Wu, Guozhen Huang, Xintong Han, Huilu Wu

    Two mononuclear Cu(I) complexes, [Cu(PBO)(PPh3)2]·PF6·CH2Cl2 (1) and [Cu(PBM)(PPh3)2]·PF6 (2) (PBO = 2-(2′-pyridyl)benzoxazole, PBM = 2-(2′-pyridyl)benzimidazole, PPh3 = triphenylphosphine), have been synthesized and characterized by elemental analyses, IR, single crystal X-ray diffraction, fluorescence spectroscopy, and cyclic voltammetry. The structural analysis revealed that in 1 and 2, the Cu(I) ions are four-coordinate and the coordination geometry around the Cu(I) is distorted tetrahedral. Photoluminescent investigation shows that 1 and 2 exhibit distinct tunable green (523 nm)-to-yellow (557 nm) photoluminescence by varying the N-heterocyclic ligands. Electrochemical properties of 1 and 2 have been investigated by cyclic voltammetry. The results suggest the frontier molecular orbits and the HOMO-LUMO energy gaps of these cuprous complexes are effectively adjusted through the introduction of different N-heterocyclic ligands.

  • Three Cd(II) coordination polymers induce gastric cancer cell apoptosis by promoting intracellular ROS accumulation and apoptotic genes expression
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-06
    Guangzhong Xu, Kai Li, Liang Wang, Yunhui Zhai, Nengwei Zhang

    In this study, three new Cd(II) coordination polymers, [Cd(TPT)(NO3)2(MeOH)](CH2Cl2) (1), [Cd3(TPT)2(NO3)6(MeOH)4](MeOH)2 (2) and [Cd(TPT)(NO3)2] (3), with structural diversity [from one-dimensional (1D) chain to 3D framework structures] have been prepared by using 2,4,6-tris-(pyridyl)-1,3,5-triazine (TPT) as ligand. The CCK-8 assay was used to explore the anti-proliferation effect of 1–3 on MKN45 gastric cancer cells, Annexin V-FITC/PI assay was performed to confirm the apoptosis and cell cycle arrest of MKN45 in a flow cytometer; the intracellular ROS level was also determined in this study. mRNA expressions of p53, nf-κb, and tnf-α in MKN45 cancer cells after treatment with 1–3 was measured by quantitative reverse transcription polymerase chain reaction. The biological results showed that 1 exerted anticancer activity through inducing apoptosis by upregulating the apoptotic genes and intracellular ROS level.

  • Strongly fluorescing silver(I) complex of a new thiadiazole ligand: X-ray crystallography, close anagostic interactions and TD-DFT emissive states
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-06
    Serkan Demir, Mahmut Gür, Nesrin Şener, İzzet Şener, Gökhan Alpaslan

    A new thiadiazole ligand, N-ethyl-5- (benzo[b]thien-2-yl-)-1,3,4-thiadiazol-2-amine (BTH), was prepared from 3-methyl-1-benzofuran-2-carboxylic acid and N-ethylhydrazinecarbothioamide precursors. Corresponding silver(I) complex, tetrakis(N-ethyl-5-(benzo[b]thien-2-yl-)-1,3,4-thiadiazol-2-amine)silver(I) nitrate [Ag2(BTH)4](NO3)2 (1), was prepared. The structures of BTH and 1 were characterized by 1H-NMR, 13C-NMR, FT-IR, elemental analysis and HR-MS techniques. Furthermore, molecular structure of 1 was illuminated by X-ray crystallography. Owing to strong anagsotic interaction, crystal structure of the complex revealed an intriguing asymmetric monomer unit even with two same ligands in 2:1 metal-to-ligand stoichiometry. Photoluminescence properties of the complex were investigated by solid and solution media emission measurements. Excited and emissive state behavior of the complex was further analyzed by quantum chemical TD-DFT calculations and natural transition orbital (NTO) analyses.

  • Structure characterization and antitumor activity of palladium pseudo halide complexes with 4-acetylpyridine
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-01
    Mohamed M. El-bendary, Muhammad N. Arshad, Abdullah M. Asiri

    The addition of an aqueous solution of palladium chloride to an aqueous acetonitrile solution of 4-acetylpyridine (4-Acpy) and KSCN or NaN3 produces new complexes, [Pd(SCN)2(4-Acpy)2] (1) and [Pd(N3)2(4-Acpy)2] (2), at ambient conditions. Complexes 1 and 2 were characterized by elemental analysis, FT-IR, and UV-Visible spectra. The structures of 1 and 2 were determined by single crystal X-ray diffraction. The coordination geometry around the palladium center is distorted square planar in 1 and 2 as the palladium is coordinated with two 4-acetylpyridine and two thiocyanates in 1 or two azide groups in 2. The discrete units of 1 and 2 extend along the a-axis creating a 1 D-chain via non-covalent hydrogen bonds. The extensive non-covalent hydrogen bonds extend the structure of 1 and 2 to 3D-networks. Using MTT assay, the cytotoxic activities of 1 and 2 were screened against two cancer cell lines, HePG-2 (liver cancer) and MCF-7 (breast cancer). The MTT assay revealed that the cytotoxic activity of 1 is stronger than 2 for HePG-2 and MCF-7. Antioxidant and anti‐hemolytic activities of 1 and 2 were examined. Furthermore, the luminescence spectra in the solid state of 1 and 2 are discussed.

  • ROS-mediated cell death induced by mixed ligand copper(II) complexes of l-proline and diimine: effect of co-ligand
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-25
    Sambantham Karpagam, Radhakrishnan Kartikeyan, Pappaiyan Paravai Nachiyar, Marappan Velusamy, Mani Kannan, Muthukalingan Krishnan, Upendra Chitgupi, Jonathan F. Lovell, Mohammad Abdulkader Akbarsha, Venugopal Rajendiran

    Abstract A series of mixed-ligand Cu(II) complexes of the type: (i) [Cu(l-pro)(diimine)(H2O)n](ClO4) (n = 0 or 1), where l-pro is l-proline and diimine is 2,2′-bipyridine (bpy; 1), (ii) 4,4′-dimethyl-2,2′-bipyridine (dmbpy; 2), (iii) 1,10-phenanthroline (phen; 3), (iv) 5,6-dimethyl-1,10-phenanthroline (5,6-dmp; 4), (v) 3,4,7,8-tetramethyl-1,10-phenanthroline (3,4,7,8-tmp; 5), (vi) dipyrido-[3,2-f:2′,3′-h]-quinoxaline (dpq; 6), and (vii) dipyrido[3,2-a:2′,3′-c]phenazine (dppz; 7) have been synthesized and characterized systematically. Complexes 2 and 3 have been structurally characterized. DNA- and protein-binding and cleavage studies revealed that 7 possesses stronger DNA- and protein-binding efficiency and also exhibits self-activating DNA-cleavage in the absence of an activating agent. The hydrophobic complexes 4 and 5 induced self-activated protein cleavage and yielded a single-cleaved fragment each. The cytotoxic property of all the seven complexes was examined by incubation with the human small cell lung carcinoma cell line A549. Complexes 4 and 6 exhibited almost similar cytotoxic properties [IC50 = 1.4 µM (4) and 1.3 µM (6)], which was 9.3 and 10 times, respectively, more efficient than cisplatin (IC50 = 13 µM). Complex 4 induced generation of the highest level of intracellular ROS which correlates with its efficient cytotoxic activity and provides scope for further investigation as a potential anticancer agent.

  • Syntheses, structure, DNA-binding and DFT studies of a Cu(II) complex based on a pyrazolone derivative
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-23
    Wei Xi, Cai-Yun Wang, Huan-Huan Meng, Xue-Qin Song

    A Cu(II) complex based on a pyrazolone derivative, 2-hydroxy-N′-((1-(4-methoxyphenyl)-3methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)(phenyl)methylene)benzohydrazide (H2L), has been prepared. IR spectra, UV-vis spectra, elemental analysis and single-crystal X-ray diffraction indicate that the Cu(II) complex was mononuclear with the chemical composition of [Cu(HL)Cl]·CH3OH. The Cu(II) compound presented herein exhibits interesting supramolecular characteristics and a novel 3D supramolecular architecture resulted due to the appropriate synergy of multiple intermolecular hydrogen bonds. The interaction of the Cu(II) complex with calf-thymus DNA was investigated by electronic absorption titration as well as EB-DNA competition experiment, and the results indicate that the Cu(II) compound which has a strong affinity for binding DNA is combined with DNA in an embedded manner. Furthermore, Time-Dependent Density Functional Theory calculations (TD-DFT) have been performed on optimized geometries for a better understanding of the electronic transitions in the UV-vis spectra of H2L and Cu(II) complex.

  • Syntheses, crystal structures and biological activity of oxidovanadium(V) complexes with tridentate aroylhydrazone ligands
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-09
    Ya-Li Sang, Xin-Hao Zhang, Xue-Song Lin, Yan-Hua Liu, Xiao-Yin Liu

    A series of oxidovanadium(V) complexes, [VOLa-cL′] (L′ = ethyl maltolate), were synthesized by reaction of VOSO4 with the aroylhydrazones 2-amino-N'-(2-hydroxybenzylidene)benzohydrazide (H2La), N'-(3-bromo-2-hydroxybenzylidene)-3-hydroxylbenzohydrazide (H2Lb) and N′-(2-hydroxy-5-nitrobenzylidene) pivalohydrazide (H2Lc), respectively. The complexes were characterized by physico-chemical methods. Molecular structures of the complexes were further characterized by single crystal X-ray diffraction. The V ions in the three complexes are coordinated by three donor atoms of the aroylhydrazone ligands, two donor atoms of the ethyl maltolate ligand, and one oxo group. Biological study of the complexes indicates that they are insulin-like agents, which stimulated glucose utilization in a dose dependent manner over the concentration range 125 μM to 1 mM.

  • Dinuclear Hg(II) complex of new benzimidazole-based Schiff base: one-pot synthesis, crystal structure, spectroscopy, and theoretical investigations
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-25
    Youssra Doria Lahneche, Houssem Boulebd, Meriem Benslimane, Mustapha Bencharif, Ali Belfaitah

    A new dinuclear complex, [HgCl2L]2, was prepared using a Schiff base derived from benzimidazole (L = [1-(1H-benzo[d]imidazol-2-yl)-N-(4-methoxyphenyl)ethan-1-imine]. The mercury complex was obtained in good yield by one-pot reaction under microwave irradiation from 2-acetylbenzimidazole and p-anisidine, followed by addition of HgCl2. The Hg(II) complex has been characterized by single-crystal X-ray diffraction analysis, IR and UV-vis spectroscopy. The mercury complex is built up from a dinuclear unit related by an inversion center through two bridging chlorine atoms. Each mercury atom is coordinated by two N atoms of the Schiff base L, one terminal Cl atom and two bridging Cl atoms in a square pyramidal geometry. To support experimental data, theoretical calculations including molecular geometry, electronic transitions and vibration frequencies of the ligand and its complex in the ground state were carried out using the global hybrid (B3LYP) density functional. In addition, a qualitative description of excited states and charge transfer character of electronic transitions states were carried out by plotting the Natural Transition Orbitals (NTOs) for main states. Theoretical calculations are in good agreement with experimental values.

  • Synthesis and characterization of dual metal zeolitic imidazolate frameworks and their application for removal of cefixime
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-06
    Abdolraouf Samadi-Maybodi, Afshin Rahmati

    Dual metal zeolitic imidazolate frameworks (ZIF-2M) containing Zn and Co were synthesized in aqueous solution. These nanoparticles were characterized by XRD, FESEM, FTIR and BET. The presence of cobalt led to improved chemical and physical properties such as crystal structure, porosity, specific area and magnetic property while keeping the basic structure of ZIFs. Nanoparticles of ZIF-2M and ZIF-8 were applied for removal of cefixime in aqueous solution. Removal efficiency was investigated for both nanoparticles under optimized conditions. Optimum conditions were achieved by BOX-Behnken design. Results revealed the sorption ability of ZIF-2M (97%) is more than that of ZIF-8 (92%). Langmuir and Freundlich isotherms for cefixime sorption by ZIF-2M in optimal conditions were also studied.

  • Reaction of [RuIII(EDTA)(H2O/OH)]−/2− with bisulfide and persulfide in aqueous solution: kinetic and mechanistic studies
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-22
    Maria Oszajca, Debabrata Chatterjee, Rudi van Eldik

    The reaction of [RuIII(EDTA)(H2O/OH)]−/2− (EDTA4− = ethylenediaminetetraacetate) with bisulfide (HS−) and persulfide (HSS−) leading to the formation of a dinuclear disulfur-bridged [(EDTA)RuIIISSRuIII(EDTA)]4− product has been studied spectrophotometrically. Kinetics of the reaction of [RuIII(EDTA)(H2O/OH)]−/2− with HS− was studied in aqueous solution as a function of [HS-] at a constant pH of 8.2 (phosphate buffer) and temperature (20 °C). Formation of the product complex, [(EDTA)RuIIISSRuIII(EDTA)]4−, in the reaction of [RuIII(EDTA)(H2O/OH)]−/2− with HSS− was identified by ESI-MS studies. A working mechanism in agreement with the spectroscopic and kinetic data is presented.

  • Review. Inverse coordination. Organic nitrogen heterocycles as coordination centers. A survey of molecular topologies and systematization. Part 2. Six-membered rings
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-07
    Ionel Haiduc

    The review is a follow-up of a previous article (I. Haiduc, J. Coord. Chem. (2019). DOI: 10.1080/00958972.2019.1641702), which introduced structures with five-membered nitrogen heterocycles as inverse coordination centers. This review presents a panorama of organic six-membered nitrogen heterocycles acting as center cores in inverse coordination metal complexes and covers pyrazine, pyrimidine, pyridazine, triazine, tetrazine, pyridine, polypyridines, piperidine, diazabicyclooctane (DABCO) and urotropine (hexamethylenetetramine) playing such a role.

  • Interaction of Pt(II) and Au(III) with organic disulfides in hydrochloric aqueous solution
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-21
    Alexander I. Petrov, Galina V. Novikova, Anastasia V. Demina, Timur Y. Ivanenko, Elizaveta S. Goleva

    (2019). Interaction of Pt(II) and Au(III) with organic disulfides in hydrochloric aqueous solution. Journal of Coordination Chemistry: Vol. 72, No. 17, pp. 2916-2930.

  • The role of N,N-chelate ligand on the reactivity of (η6-p-cymene)Ru(II) complexes: kinetics, DNA and protein interaction studies
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-22
    Gershom Kyalo Mutua, Rajesh Bellam, Deogratius Jaganyi, Allen Mambanda

    This study reports the kinetic studies of aqua complexes (Ru1–Ru6) as well as the calf-thymus DNA (CT-DNA) and bovine serum albumin binding studies of their chloro derivatives (Ru7–Ru11). The rate of substitution of the aqua ligand(s) in Ru1–Ru6 by thiourea nucleophiles (thiourea, N,N-dimethylthiourea and N,N,N′,N′-tetramethylthiourea) in 0.1 M HClO4/NaClO4 aqueous medium was investigated as a function of nucleophile concentration and temperature under pseudo-first order conditions. The reactivity of the binuclear and mononuclear complexes decreased in the order Ru3 > Ru4 > Ru5 > Ru6 and Ru1 > Ru2, respectively. The trend in reactivity of the binuclear complexes showed a dependence on the electronic and static factors of the rigid N,N-chelate bridging ligand in the complexes. The reactivity trends are well supported by the DFT-calculated data. The activation parameters (ΔH≠ > 0, ΔS≠ < 0) for the substitution process in all complexes support an associative mechanism of activation. The complexes effectively bind to CT-DNA via intercalation and this was corroborated by the molecular docking results. Likewise, the complexes bind favorably with bovine serum albumin. The order of CT-DNA and bovine serum albumin interactions with these complexes are in line with the trends in aqua ligand substitution.

  • Preparation, characterization, pH titration, and electrochemical properties of an anthracene-bridged binuclear ruthenium complex containing imidazole
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-23
    Hongju Yin, Feixiang Cheng, Zining Liu, Chixian He, Yuting Yang, Kezhi Wang

    By using an anthryl-phenyl-imidazo-phen as a pH responsive ligand, a binuclear ruthenium complex has been synthesized as a pH luminescence probe under visible light excitation at 460 nm. The ground- and excited-state acid–base properties of the complex were studied by UV–visible and emission spectrophotometric pH titrations. The excited-state ionization constants of pKa2* = 6.92 is in a physiologically relevant regime and the complex is an “on-off” type fluorescent pH sensor. In addition, electrochemical studies of the binuclear ruthenium complex show one Ru(II)-centered oxidation at 1.29 V and three ligand-centered reductions.

  • Three keggin-templated compounds constructed by flexible ligands: syntheses and electrochemical properties
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-31
    Haichen Mou, Guiying Liu, Xinyi Jia, Aixiang Tian, Mengle Yang, Yubo Fu, Yan Yang, Jun Ying

    By using the Keggin anion [SiMo12O40]4− as a template and bis(triazole) derivatives as organic ligands, three compounds were synthesized, [Zn2(bte)4(SiMo12O40)]·H2O (1), [Zn4(btb)8(SiMo12O40)2] (2) and [Zn2(bth)4(SiMo12O40)] (3) (bte = 1,2-bis(1,2,4-triazol-1-yl)ethane, btb = 1,2-bis(1,2,4-triazol-1-yl)butane and bth = 1,2-bis(1,2,4-triazol-1-yl)hexane). Compound 1 has a cross-shaped cycle-connecting-cycle chain, with two Keggin anions locating above and below for each cycle. By increasing the spacer length of the ligands, a 2D double-layer is formed in 2. The Keggin anions are embedded in the grids of the double-layer. Compound 3 exhibits a wave-like 2D layer with large grids. The two layers penetrate in the form of crests to crests. The anions are covered by these two penetrated layers. The Keggin anions induce distinct metal-organic subunits in 1–3 as the templates. We found that these compounds show electrocatalytic activity for ascorbic acid, bromate and nitrite. All these compounds can be used as electrochemical sensors for nitrite and show good selectivity for NO2− ions.

  • Synthesis of N-benzylated cobalt phthalocyaninetetrasulfonamide and its application in oxidative desulfurization catalysis
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-11-01
    Deependra Tripathi, Himani Negi, Raj K. Singh, Udai P. Singh, Vimal C. Srivastava

    The FeCl2/K2CO3 catalyst system was used successfully for the synthesis of oil soluble N-benzylated cobalt phthalocyaninetetrasulfonamide by the reaction of benzyl alcohol on water-soluble cobalt phthalocyaninetetrasulfonamide via heating at 135 °C for 20 h under N2. The new oil-soluble peripherally N-benzylated phthalocyanine was characterized by elemental analysis, FT-IR, UV–vis, TG and mass spectrometry. The catalytic activity of this new cobalt complex for oxidation of dibenzothiophene (DBT) was evaluated in n-dodecane (a middle distillate model compound) using H2O2 as an oxidant. The acetonitrile was taken as an extracting solvent for further extracting DBT sulfoxide and sulfone. The novel peripherally substituted cobalt(II) complex showed better oxidative desulfurization catalytic activity than cobalt phthalocyanine and cobalt phthalocyaninetetrasulfonamide. DBT oxidation kinetics were evaluated by lumped nth- and first-order kinetic models. The maximum removal of the DBT was found to be 85% at the optimized dose and experimental conditions.

  • Synthesis, DFT analysis, and electronic properties of new phthalocyanines bearing ETAEO substituents on peripheral position
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-23
    Beyza Cabir, Umit Yildiko, Mehmet Salih Ağirtaş

    (2019). Synthesis, DFT analysis, and electronic properties of new phthalocyanines bearing ETAEO substituents on peripheral position. Journal of Coordination Chemistry: Vol. 72, No. 17, pp. 2997-3011.

  • Synthesis and photocatalytic characterization of fluorescent conducting β2-SiW11Ti/PANI dopant material
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-09
    Rui Cao, Ronghua Ma

    β2-SiW11Ti/PANI was synthesized in the solid-phase and characterized by UV–Vis, IR spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N2 adsorption desorption, and fluorescence spectroscopy. Thermal stability and conducting behavior were studied. Dopant material exhibited excellent photocatalytic properties for degradation of methylene blue in aqueous solution under UV and sunlight irradiation. The possible mechanism of photocatalytic activity of dopant material was also discussed and schematized.

  • Binuclear ruthenium(II) complexes of 4,4′-azopyridine bridging ligand as anticancer agents: synthesis, characterization, and in vitro cytotoxicity studies
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-07
    Priyanka Khanvilkar, Ramadevi Pulipaka, Kavita Shirsath, Ranjitsinh Devkar, Debjani Chakraborty

    Four new binuclear Ru(II)-arene complexes with N-ferrocenyl amino acid ligands and 4,4′-azopyridine as the bridging group [(p-cym)(Fc-AA)Ru(μ-azpy)Ru(Fc-AA)(p-cym)]Cl (C1–C4; where p-cym = p-cymene, MeC6H4Pri; Fc-AA = N-ferrocenyl amino acid conjugate ligands (Fc-tyr 1, Fc-phe 2, Fc-leu 3, Fc-trp 4) and azpy = 4,4′-azopyridine) were synthesized and characterized by 1H NMR, UV—visible, FTIR and mass spectroscopy, and CHN analysis. The structure of one of the precursor mononuclear complexes, [(p-cym)Ru(Fc-phe)Cl], was determined by single-crystal X-ray diffraction studies. Binding of the complexes with calf-thymus DNA and bovine serum albumin (BSA) has been evaluated using absorption and emission spectral studies. Ethidium bromide-displacement studies and DNA-viscosity measurements affirmed intercalative interaction mode between complexes and CT-DNA. Fluorescence titration was used to explore interaction of the complexes with BSA. MTT assay was adopted to evaluate the anticancer activity of C1–C4 on HeLa cell line and the corresponding IC50 values were calculated. The IC50 values of the complexes were higher than that for cisplatin but much lower than for NAMIA and RAPTA-C. The lower cytotoxicity of C1–C4 compared to cisplatin is explained based on nucleotide excision repair mechanism.

  • Synthesis, structure and catalytic promiscuity of a napthyl-pyrazole Mn(II) complex and structure–activity relationships
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-03
    Abhimanyu Jana, Paula Brandão, Harekrishna Jana, Atish Dipankar Jana, Gopinath Mondal, Pradip Bera, Ananyakumari Santra, Ajit Kumar Mahapatra, Pulakesh Bera

    The napthyl/pyridine-pyrazole-derived complexes, [Mn(L1)Cl2] (1), [Co(L1)Cl2] (2), [Cu(µ-Cl)(Cl)(L)]2 (3), [Cu2(L)2(N3)3(µ2-N3)] (4), and [Co(L2)Cl2] (5) (where L1 = bis-(3,5-dimethyl-pyrazol-1-ylmethyl)-napthalen-1-ylmethyl-amine (L1), L = 5-methyl-pyrazol-1-ylmethyl) -napthalen-1-ylmethyl-amine (L) and L2 = 2-[2-(3,5-dimethyl-pyrazol-1-yl)-1-methyl-ethyl]-pyridine), exhibited phenoxazinone synthase activity in methanol in the range 5–54 h−1. Binuclear copper(II) derivatives 3 and 4 show better catalytic activities than manganese(II) and cobalt(II) derivatives. The kinetic studies reveal that phenoxazinone chromophore is produced via a complex-substrate intermediate. Further, 3 and 4 show catecholase activity in methanol in the presence of oxygen. All the complexes showed potent antimicrobial activity against the tested strains of bacteria and fungi. Complex 1 was synthesized for the first time by mixing L1 and MnCl2 (1:1) and characterized by single-crystal X-ray crystallography, cyclic voltammetry, density functional theory, and thermogravimetry analysis. The present study suggests that napthyl/pyridyl-anchored pyrazole metal complexes are interesting scaffolds for the development of novel model compounds for biochemical reaction and efficient antimicrobial agents.

  • Synthesis, structural, electrochemical and spectroscopic characterization, and theoretical calculations of two new Cu(II) and Ni(II) complexes from 2-(1-((pyridine-2-ylmethyl)imino)ethyl)naphtalen-1-ol
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-03
    Keily J. Gutiérrez, Wilfredo M. Pedreira, Dalice M. Piñero Cruz

    We present the synthesis of the tridentate Schiff base 2-(1-((pyridine-2-ylmethyl)imino)ethyl)naphtalen-1-ol (LH) providing a NNO coordination environment. Two new Ni(II) and Cu(II) complexes with a ligand to metal stoichiometric ratio of 1:1 and 2:1, respectively, were synthesized from LH. The Cu(II) complex of general formula [Cu(L)(MeOH)](ClO4)·MeOH (2) has a square planar geometry in the central ion completed by a MeOH molecule. In the case of the mononuclear Ni(II) complex [NiL2]·MeOH (3) the central ion has a distorted octahedral geometry. These new compounds were structurally, spectroscopically and electrochemically characterized using X-ray diffraction, UV-vis, IR, 1H NMR, 13C NMR spectroscopies, and cyclic voltammetry. LH is electroactive in the potential window of −1.0 to 1.0 V with one irreversible oxidation at 0.44 V, a quasi-reversible oxidation at 0.60 V, and one irreversible reduction at 0.24 V. For 2, there is a quasi-reversible oxidation at 0.43 V and one irreversible oxidation at 0.64 V. Complex 3 has two quasi-reversible oxidations at 0.19 V and at 0.58 V, one irreversible oxidation at 0.37 V, and one irreversible reduction at 0.38 V. DFT calculations were undertaken to obtain optimized structures and relative stability for 2 and 3 and their intermediates.

  • Synthesis, spectral characterization, DFT, and molecular docking studies of metal(II) complexes derived from thiophene-2-carboxaldehyde and 2-amino-6-picoline
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-23
    Liji John, R. Selwin Joseyphus, I. Hubert Joe

    A novel series of metal complexes ML2Cl2 [M = Co(II), Ni(II), Cu(II), and Zn(II), L = Schiff base] have been synthesized by the interaction of the ligand derived from the condensation of thiophene-2-carboxaldehyde with 2-amino-6-picoline. Molar conductance measurements indicate that the complexes are non-electrolytes. Infrared data indicate that the ligand is monodentate and binds to the metal ion via azomethine nitrogen atom. Electronic spectral data and magnetic measurements reveal tetrahedral and square planar geometries for the metal complexes. The redox behavior of complex [CuL2Cl2] has been investigated using cyclic voltammetry. Thermal decomposition profiles are consistent with the proposed formulation of the complexes. The XRD and SEM results indicate that ligand and complexes [CuL2Cl2] and [ZnL2Cl2] are nanocrystalline. The metal complexes showed higher photocatalytic efficiency under sunlight as evidenced by photocatalytic studies using methylene blue dye. Molecular structures of the ligand and its complexes have been optimized by DFT computations. Binding affinity of ligand and its complexes with target protein have been examined by molecular docking study. The in vitro antimicrobial activity of the synthesized compounds has been tested against certain bacterial and fungal species. Furthermore, in vitro cytotoxicity of complexes [CoL2Cl2] and [CuL2Cl2] have been tested against L929 fibroblast.

  • Bioactive NHC-derived palladium complexes: synthesis, catalytic activity for the Suzuki-Miyaura coupling of aryl chlorides and bromides and their antibacterial activities
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-23
    Lamia Boubakri, Abdullah S. Al-Ayed, L. Mansour, Nael Abutaha, Abdel Halim Harrath, I. Özdemir, S. Yasar, Naceur Hamdi

    Pd(II)-bis(NHC) complexes (where NHC = N-heterocyclic carbene) bearing asymmetrically and symmetrically substituted NHC-ligand have been synthesized via deprotonation of 5,6-dimethylbenzimidazolium salts. The NHC precursors have been achieved via the two step N-alkylation of 5,6-dimethylbenzimidazole. The resultant salts were deprotonated with PdCl2 and K2CO3 in dry THF for 2(a–e). The obtained complexes were identified and characterized by 1H and 13C NMR, FT-IR, DART-TOF mass spectrometry and elemental analysis. These new Pd(II)-bis(NHC) complexes were applied as catalyst precursors for Suzuki-Miyaura cross-coupling reactions of aryl bromides and chlorides with phenylboronic acid to afford the corresponding products in good yields. This catalytic reaction was evaluated in the presence of KOtBu/toluene. The antibacterial activities of 2(a–e) were investigated against Gram (+)/(−) bacteria using the agar dilution procedure. The antibacterial activities of 2 vary with the nature of the ligands; MIC values of 2(a–e) were determined.

  • Synthesis and catalytic performance of 2-ferrocenylpyridine palladacycle complexes
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-16
    Ligang Yan, Limin Han, Ruijun Xie

    Seven 2-ferrocenylpyridine palladacycle complexes, [PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]-Py}(PPh3)] (1), PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]- Py}(Py)] (2), [PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]-Py}(4-FcPy)] (3), [PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]-Py}(4-PhPy)] (4), [PdCl{2-[(η5-C5H5)]-Fe[(η5-C5H3)]-Py}(4-tBuPy] (5), [PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]-Py}(4-MePy)] (6), and [PdCl{2-[(η5-C5H5)]Fe[(η5-C5H3)]-Py}(4-MeOPy)] (7), were synthesized by using dichlorobis-(2-ferrocenylpyridine)palladium dimer as a precursor and pyridine derivatives as ancillary ligands, and characterized by elemental analysis, FT-IR, and NMR. The molecular structures of 1–5 were determined by single crystal X-ray diffraction; the square-planar palladium centers were slightly influenced by the ancillary ligand. The 13C NMR of ferrocenyl carbon (Pd-C) shifted from 97.72 to 98.39 ppm which was used as an indicator of different electron-donating ability of ancillary ligands. The catalytic performance of seven complexes for the Suzuki–Miyaura reaction of 4-iodotoluene and phenylboronic acid were evaluated under inert conditions and in air. The yields of 4-methylbiphenyl are 68–95%. Effects of ancillary ligands were explored in the catalytic mechanism.

  • Synthesis and photocatalytic activity of MnV13/GO/PANI composite catalysts
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-01
    Cheng-Li Zhang, Rong-Hua Ma

    Graphene oxide was prepared by modified Hummers method, MnV13/GO composite was prepared by solution blending method, and MnV13/GO/PANI composite catalyst was prepared by interfacial method. The catalyst was characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption-desorption. The results show that the V-O-V bonds of the polymerized heteropoly complex are blue-shifted and the V-Od bonds are red-shifted slightly from conjugation between V-Od and GO lamellae. The photocatalytic properties of the catalyst for malachite green showed that degradation of malachite green was 92.7% after 200 min of UV irradiation. The degradation under sunlight was better than that under ultraviolet light, reaching 97.2%. The degradation of malachite green by the catalyst is a first-order kinetic reaction. We find that such a MnV13/GO/PANI composite exhibits higher photocatalytic activity than MnV13/GO, MnV13 and GO toward the liquid-phase degradation of malachite green under both UV and sunlight irradiation. The presence of synergic effect between PANI and MnV13 is believed to play an essential role in affecting the photoreactivity. At last, the roles of active species in the photocatalytic process are compared by using different types of active species scavengers. The degradation mechanism of the photocatalysts is proposed.

  • Preparation and photocatalytic kinetic study of ternary composite photocatalyst 12-phosphotungstic acid/PANI/SnO2
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-10
    Ma Rong-Hua, Sun Yan

    Using (NH4)2S2O8 as an oxidant and 12-phosphotungstic acid as a doping agent, the ternary composite material PW12/PANI/SnO2 was prepared. The photocatalyst was characterized by FT-IR, XRD, UV-Vis, N2 adsorption-desorption tests, SEM and XPS techniques. The PANI additive was useful to reduce the agglomeration of nanoparticles and improve the dispersion because of hydrogen bonding between PANI and SnO2. XRD image showed that SnO2 has planar orientation and purity. The photocatalytic activities of the composite were investigated for the degradation of gentian violet as a probe under illumination with UV. The effect of different factors and different conditions for gentian violet is discussed. Results show that after 30 W UV irradiation, the degradation rate is 96.23%. The composite catalyst is better than SnO2, PW12 and SnO2/PANI with higher activity. Photocatalytic degradation of gentian violet is a first-order reaction.

  • Synthesis and characterization of some novel Mn(III) glycinato complexes with catalytic applications
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-10
    Deepika Jaiswal, Sudha Yadava

    Tris(glycinato)Mn(III) and its mixed ligand complexes with azido-, thiocyanato-, chloro- and bromo- groups have been synthesized and characterized by UV–Vis spectrophotometry, IR spectrophotometry, elemental analysis, magnetic susceptibility measurements, thermal analysis, Dart-mass spectrometry, EPR spectral studies, and X-ray powder diffraction studies. The molar extinction coefficient values of the complexes are in the range of spin allowed 5T2g → 5Eg transitions. The magnetic susceptibility measurements of all the complexes confirmed the presence of four unpaired electrons and high spin d4 systems. Room temperature EPR spectrum gives g isotropic value 2.002 indicative of octahedral geometry for the complex. PXRD studies suggest monoclinic system with space group P21/c with a = 9.1382(60) Å, b = 15.5340(11) Å, c = 10.2576(68) Å, and β = 110.598(15)°. The particle size of the complexes lies in the range 26.60–38.79 nm. The tris(glycinato)Mn(III) is an efficient heterogeneous catalyst for decolorization of Xylenol Orange and Methyl Red in the presence of H2O2. It also initiates polymerization of acrylonitrile.

  • Synthesis, characterization, and photocatalytic activity of Co(II) and Cu(II) phthalocyanines linked with thiophene–Schiff base substituents for 4-nitrophenol oxidation
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-08-27
    Ayse Aktas Kamiloglu, Ece Tugba Saka, Irfan Acar, Kader Tekintas

    A phthalonitrile derivative 4-{4-[(E)-(thiophen-2-ylmethylidene)amino]phenoxy}phthalonitrile (2) and its Co(II) and Cu(II) phthalocyanine derivatives (2a, 2b) are reported. The compounds have been characterized by spectroscopic techniques (IR, NMR, UV–Vis, and MS) and elemental analyses (for the metallophthalocyanines). Photocatalytic activities of 2a and 2b on 4-nitrophenol (4-NP) oxidation are reported. Parameters influencing the photooxidation process were determined; 4-NP oxidizes to less harmful products with high conversion and yield in the presence of Co(II) and Cu(II) phthalocyanine catalysts.

  • Electrocatalytic activity of cobalt tris(4-nitrophenyl)corrole for hydrogen evolution from water
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-01
    Hai Chen, Dong-Lan Huang, Md Sahadat Hossain, Guo-Tian Luo, Hai-Yang Liu

    Catalytic activities for hydrogen (H2) evolution of cobalt 5,10,15-tris(phenyl)corrole (1) and 5,10,15-tris(4-nitrophenyl)corrole (2) (in homogeneous system was examined from acetic acid and water. In phosphate buffer solution (pH 7.0), the hydrogen evolution turnover frequency (TOF) for 1 and 2 were 62 and 150 h−1 at the overpotential of −1.53 V versus Ag/AgCl. In acetic acid media, hydrogen evolution TOF for 1 and 2 were 56 and 127 h−1, respectively, at an overpotential of 961 mV versus Ag/AgNO3. In the practical electrocatalytic hydrogen evolution experiment at −1.45 V (vs. Ag/AgCl) overpotential for 1 h, the TOF were 76 and 188 h−1 for 1 and 2, respectively. No observable decomposition of the catalyst could be observed after electrolysis for 72 h with a glassy carbon electrode.

  • Chalconoid metal chelates: spectral, biological and catalytic applications
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-09
    Jino Johnson, A. Yardily

    This review presents an outline of the spectral and biological applications of metal complexes containing chalcone and its derivatives as ligands. Chemotherapy was more or less completely based on natural products and organic compounds. However, in recent times chalcone–metal complexes have received a great deal of consideration as chemotherapeutic agents. A lot of biologically active compounds used as drugs possess modified pharmacological and toxicological potentials when administered in the form of metal-based compounds. The studies on chalcone derived transition metal complexes have been of interest because of its possible application in medicinal chemistry and catalysis. Diverse coordination environments, tunable spectral and redox properties make them valuable in many ways. Overall this review aims to provide a general overview of this emerging and rapidly expanding area of research.

  • Syntheses, structures of Mn(II), Ni(II), Cu(II) and Zn(II) coordination complexes based on 3,4,5-trifluorobenzeneseleninic acid and N-donor ligands
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-04
    Mao Yan, Shuai Chen, Ru-Fen Zhang, Qian-Li Li, Shao-Liang Zhang, Chun-Lin Ma

    Five new coordination complexes [MnII (L1)2(4,4′-bpy)]n (1), [NiII (L1)2(4,4′-bpy)]n (2), [ZnII (L1)2(4,4′-bpy)]n (3), [CuII (L1)2(phen)2]Cl2 (4) and [CuII 2(L1)2(2,2′-bpy)2]Cl2 (5) (HL1 = 3,4,5-trifluorobenzeneseleninic acid, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline), have been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis and IR spectroscopy. Complexes 1–3 display similar layers structures. In 1–3, the adjacent layers are further connected through π···π interactions to form three-dimensional supramolecular structures. Complexes 4 and 5 show a dimer containing an eight-membered ring. The dimer extends into three-dimensional supramolecular structures through π···π interactions, C–H···F and C–H···Cl interactions.

  • Synthesis, characterization, and electrochemistry of five diiron propane-1,3-dithiolate complexes with substituted phosphine ligands
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-30
    Lin Yan, Meng-Yuan Hu, Chao Mu, Ao Li, Xu-Feng Liu, Pei-Hua Zhao, Yu-Long Li, Zhong-Qing Jiang, Hong-Ke Wu

    In this paper, five diiron propane-1,3-dithiolate complexes containing substituted phosphine ligands were prepared and structurally characterized. Treatment of [Fe2(CO)6(μ-SCH2CH2CH2S)] (1) with a monophosphine ligand methyl diphenylphosphinite, ethyl diphenylphosphinite, 4-(dimethylamino)phenyldiphenylphosphine, tris(2-methoxyphenyl)phosphine, or tris(4-chlorophenyl)phosphine in the presence of Me3NO·2H2O as the decarbonylating agent gave the corresponding phosphine-substituted analogues [Fe2(CO)5(L)(μ-SCH2CH2CH2S)] [L = Ph2POCH3, 2; Ph2POCH2CH3, 3; Ph2P(4-C6H4 NMe2), 4; P(2-C6H4OCH3)3, 5; P(4-C6H4Cl)3, 6] in 73–93% yields. Complexes 2–6 have been characterized by elemental analysis, spectroscopy, and X-ray crystallography. Additionally, electrochemical studies have shown that 2–6 can catalyze the reduction of protons to H2 in the presence of HOAc.

  • Synthesis, characterization, and electrochemistry of phosphine-substituted diiron butane-1,2-dithiolate complexes
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-03
    Hui-Min Lin, Chao Mu, Ao Li, Xu-Feng Liu, Yu-Long Li, Zhong-Qing Jiang, Hong-Ke Wu

    The reactions of the starting complex, [Fe2(CO)6{μ-SCH2CH (CH2CH3)S}] (1), with the phosphine ligands tris(4-methylphenyl)phosphine, diphenyl-2-pyridylphosphine, tris(4-fluorophenyl)phosphine, 2-(diphenylphosphino)benzaldehyde, or benzyldiphenylphosphine in the presence of the decarbonylating agent Me3NO·2H2O yielded the corresponding phosphine-substituted diiron butane-1,2-dithiolate complexes [Fe2(CO)5(L){μ-SCH2CH(CH2CH3)S}] (L = P(4-C6H4CH3)3, 2; Ph2P(2-C5H4N), 3; P(4-C6H4F)3, 4; Ph2P(2-C6H4CHO), 5; Ph2PCH2Ph, 6) in 75%–87% yields. The complexes have been characterized by elemental analysis, IR, 1H, and 31P{1H} NMR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Moreover, the electrochemistry of 2–4 was studied by cyclic voltammetry, suggesting that they can catalyze the reduction of protons to H2 in the presence of HOAc.

  • Phosphine-substituted diiron 1,2-dithiolate complexes as the models for the active site of [FeFe]-hydrogenases
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-20
    Lin Yan, Jiao He, Xu-Feng Liu, Yu-Long Li, Zhong-Qing Jiang, Hong-Ke Wu

    In this article, five diiron 1,2-dithiolate complexes containing phosphine ligands are reported. Treatment of complex [Fe2(CO)6(μ-SCH2CH2S)] (1) with the phosphine ligands tris(4-methylphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(3-chlorophenyl)phosphine, tris(3-methylphenyl)phosphine, or 2-(diphenylphosphino)biphenyl in the presence of Me3NO·2H2O as the decarbonylating agent afforded the target products [Fe2(CO)5(L)(μ-SCH2CH2S)] [L = P(4-C6H4CH3)3, 2; P(4-C6H4OCH3)3, 3; P(3-C6H4Cl)3, 4; P(3-C6H4CH3)3, 5; Ph2P(2-C6H4Ph), 6] in 80–93% yields. Complexes 2–6 have been characterized by elemental analysis, spectroscopy, and X-ray crystallography. Additionally, the electrochemical properties were studied by cyclic voltammetry.

  • A linear chain of carbazolyl-bis(tetrazole) supported copper(II) dimers held together by bridging tribromide anions
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-03
    Huang Jie, Leah Gajecki, David J. Berg, Allen G. Oliver

    Reaction of NaCzTiPr with CuBr, followed by exposure to air, results in formation of {[Cu(κ3-N3-μ-N’-CzTiPr)(μ-OH)]2[μ-Br3]}x, 2. The structure of 2 in the solid state consists of hydroxo-bridged Cu(II) dimers connected into a linear chain polymer by bridging Br3– units. The Cu(II) centers have axially elongated coordination with a Br3– terminus and a bridging N from a tetrazole on the adjacent Cu forming the ligands on the long axis. The Br3– unit is linear with short Br–Br distances while the Cu–Br–Br angle is close to 90°. The reaction involves oxidation of both the Cu(I) and Br– of CuBr in air.

  • Platinum(II), palladium(II), and gold(III) complexes of dianionic, secondary dithiooxamide ligands
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-14
    Haiming Tang, Graham C. Saunders, William Henderson

    Reactions of the complexes cis-[PtCl2(PPh3)2], [PdCl2(dppe)] (dppe = Ph2PCH2CH2PPh2) and the N,C-cycloaurated gold(III) complexes [AuCl2(2-benzylpyridyl)] and [AuCl2(C6H4CH2NMe2)] with the secondary dithiooxamide EtNHC(S)C(S)NHEt in refluxing methanol with Et3N base gave good yields of the respective neutral dithiooxamide complexes containing a doubly deprotonated dithiooxamide ligand. The Pt and Pd complexes, as well as [Au{SC(NEt)C(NEt)S}(C6H4CH2NMe2)], were characterized by single-crystal X-ray diffraction. In all complexes the ligand is S,S-bonded to the metal center. The complexes were also characterized by NMR spectroscopy and ESI mass spectrometry.

  • Synthesis, crystal structure, and BSA interaction with a new Co(II) complex based on 5-(trifluoromethyl)pyridine-2-carboxylic acid
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-20
    Bing Li, Jiakai Wang, Huan Song, Huanping Wu, Xiaoyan Chen, Xiaoxia Ma

    A new complex, Co(Htpc)2(H2O)2 (1) (Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid), has been synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, infrared spectral analysis, and thermogravimetric analysis. Meanwhile, the optimized geometric structure of the ligand was determined using the M06-2X functional of density functional theory (DFT) with the 6-311 + G(d, p) basis set. The gap energies ΔE between the frontier molecular orbitals were computed in different solvent media (water, methanol and ethanol) using the time dependent density functional theory (TD-DFT)/M06-2X by applying the Polarizable Continuum Model (PCM). The coordination sphere around Co(II) is distorted octahedral with two chelating tpc- ligands and two coordinated water molecules. Bovine serum albumin (BSA) binding properties of the ligand, CoCl2·6H2O and 1 were investigated by fluorescence and UV–Vis absorption spectroscopy, revealing 1 exhibits higher binding affinity with BSA than free ligand and CoCl2·6H2O. ΔG, ΔH and ΔS at 298 and 308 K manifested that van der Waals interactions and hydrogen bonds were the main forces in the binding process.

  • Syntheses, X-ray structure, emission and vibrational spectroscopies, DFT and thermogravimetric studies of two complexes containing the bidentate ligand 5-phenyl-1H-pyrazol-3-yl)methyl) phosphine oxide
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-10-09
    Rudy L. Luck, John S. Maass, Nick K. Newberry, Matthias Zeller

    The coordination chemistry of (diphenyl((5-phenyl-1H-pyrazol-3-yl)methyl) phosphine oxide), 1, was explored. Reacting appropriate equivalents of this ligand and either cobalt perchlorate or MoO2Cl2 results in formation of [Co((C6H5)2POCH2(C3N2H2)(C6H5))2(C4H8O)2][ClO4]2, 2, and MoO2Cl2((C6H5)2POCH2(C3N2H2)(C6H5))(THF), 3. Complexes were characterized by FTIR, NMR, TGA and elemental analyses. Single crystal X-ray spectroscopy reveals octahedral geometries for both compounds. Complex 2 consists of two trans THF ligands in axial positions and two (diphenyl((5-phenyl-1H-pyrazol-3-yl)methyl) phosphine oxide) ligands occupying equatorial positions resulting in an overall octahedral geometry. Two perchlorate counter anions complete the structure. The Co ion resides on an inversion point. THF contains disorder with the four carbon atoms and the major orientation refined to an occupancy of 86.1(9)%. Complex 3 consists of the cis-dioxo MoO2 unit bonded with axial trans-chloride ligands and 1 in the equatorial plane completing the disordered octahedral geometry. A THF ligand is hydrogen bonded to the H-atom on the nitrogen of the pyrazole moiety in ligand 1. DFT calculations based on geometries obtained crystallographically were useful in assigning FTIR peaks and the UV-vis spectra.

  • Cyanosilylation of aldehydes catalyzed by a porous metal-organic framework containing a coordinatively unsaturated Zn(II) center and its anticancer activity in human osteogenic sarcoma
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-05
    Yu-Xu Li, Gang Chen, Qiang Xiao, Jin-Hui Cheng, Zhi-Sheng Long, Liang Deng, Ling Ma, Fei-Peng Gong

    Solvothermal reaction of Zn(NO3) · 6H2O with the tripodal ligand 1,3,5-tris(4-carboxyphenyl)benzene (H3BTB) afforded a highly porous metal-organic framework (MOF) {[Zn3(BTB)2(H2O)2] · 7DMF}n (1). The resulting activated 1a exhibits BET surface areas of 1021 m2 g−1 with a pore size distribution around 11.8 Å, which was further applied in the cyanosilylation of aldehydes under solvent-free conditions. The experimental results show that, using 1a as the catalyst, both aliphatic and aromatic aldehydes were efficiently transformed to cyanohydrin trimethylsilyl ether. Meanwhile, significant size selectivity and electronic effects have also been observed. Then, we evaluated the anticancer activity of the synthesized compound 1a on six different kinds of cancer cell lines, including HeLa, CHO, HepG2, MG-63, MAD-MB-435, and BEAS-2B. CCK-8 results indicated 1a showed excellent inhibitory effect on cell proliferation, especially on the MG-63 human osteogenic sarcoma cells. Next, a transwell assay was performed to detect the migration and invasion activity of MG-63 cells after compound 1a treatment.

  • Synthesis and structural characterization of a barium coordination polymer based on a μ2-monoatomic bridging 4-nitrobenzoate
    J. Coord. Chem. (IF 1.685) Pub Date : 2019-09-30
    Pooja H. Bhargao, Bikshandarkoil R. Srinivasan

    The synthesis, spectral characterization, crystal structure and properties of [Ba(H2O)2(NMF)2(4-nba)2], 1 (NMF = N-methylformamide; 4-nba = 4-nitrobenzoate), are reported. 1H and 13C NMR spectral data reveal the presence of NMF in 1. A strong band at 1660 cm−1 in the infrared spectrum indicates the binding of amide oxygen to Ba(II) which is confirmed by the single crystal structure. The unique Ba(II) in 1 situated on a mirror plane exhibits nine coordination and is bonded to two symmetry related monodentate terminal NMF ligands via the amide oxygen, and a terminal aqua ligand. The μ2-monoatomic bridging binding mode of each of a crystallographically independent 4-nba ligand and a unique water ligand link the Ba(II) cations into an infinite chain extending along a, leading to the formation of a 1D coordination polymer with Ba···Ba separations of 4.2522(3) Å. In the chain, the {BaO9} polyhedra are linked in a face sharing fashion. Thermal decomposition of 1 results in the formation of BaCO3 residue. A comparative study of the structural chemistry of several barium coordination polymers is described.

Contents have been reproduced by permission of the publishers.
上海纽约大学William Glover