Open‐cage silsesquioxane, in which traditional closed‐cage silsesquioxane is partially hydrolyzed, is a promising class of building blocks for constructing organic‐inorganic hybrid. It has advantages in high thermal stability, low crystallinity, transparency, designability, etc. Although the structural effects of closed‐cage silsesquioxanes have been elucidated in detail so far, those of open‐cages have never been studied. Herein, we synthesized corner‐ and side‐opened cage silsesquioxanes having carbazole units at the open moieties. The former was amorphous in the solid state and polymer matrix, while the latter formed crystalline structures. These different packing structures caused significant difference in the performance as an emission layer of organic light emitting device.

We present a Pt-catalyzed direct coupling of benzene to biphenyl. This catalytic reaction employs the cyclometalated platinum(II) complex [PtMe(bhq)(SMe2)] (bhq = benzo[h]quinolate) with PhI(OAc)2 as oxidant and does not require an acid, a co-catalyst or a solvent. Reaction kinetics and characterization of potential catalytic species are reported. The reaction is first-order in Pt and second-order in benzene, which implicates the second C-H activation step as rate-determining. A Pt(II)/Pt(IV) catalytic cycle is suggested. The reaction commences by oxidation of the Pt(II) complex to give the platinum(IV) species [Pt(bhq)(SMe2)(OAc)2](OAc) followed by C-H activation of benzene to afford the intermediate [PtPh(bhq)(SMe2)(OAc)](OAc) concurrently with release of HOAc. A second benzene molecules reacts similarly to give the diphenyl intermediate [PtPh2(bhq)(SMe2)](OAc). C-C bond forming reductive elimination ensues to regenerate Pt(II) and complete catalytic cycle. The proposed mechanism has been examined by DFT computations, which provides support to experimental findings.

Platinum(IV) complexes with a heterocyclic ligand and ancillary ligand have been investigated and applied in treating various tumour cell lines. Another application of the Pt(IV) complexes in forming peptide disulfide bonds was investigated in this work. For development of the Pt(IV) complex chemistry for disulfide bonds formation in peptides, two Pt(IV) complexes, [PtCl2(phen)(en)]Cl2 and [PtCl2(bpy)(en)]Cl2, were synthesized and characterized using elemental analysis, ESI-MS and NMR. Subsequently, they were investigated as the oxidants for the formation of disulfide bonds in various peptides. Excellent purities and yields of disulfide-containing peptides were achieved when the reactions were carried out in aqueous solution. The reactions were completed rapidly in a wide range of pH even in acidic medium at room temperature. Intramolecular-disulfide bond was formed in each of peptides in the solution containing two dithiol-containing peptides, making the Pt(IV) complexes are useful for disulfide-containing peptide libraries. Additionally, the two Pt(IV) complexes can be used as oxidants for the synthesis of disulfide bonds on resin, making the synthesis more automatically in manufacture.

An aminopyridinato ligand stabilized and coordinativelly unsaturated dimeric tungsten(0) complex having an electronic structure with six metal centred HOMOs (σ2,π2,π2,δ2,δ2,δ*2) has been isolated and structurally characterized. Reaction of it with cryptand leads to C-H activation of one of the isopropyl group of the N-ligand to form a dimeric tungsten (I) complex.

Photothermal therapy (PTT) is a promising treatment for tumor due to efficient and noninvasive speciality. However, during the PTT treatment, reactive oxygen species (ROS) will be produced in response to the hyperthermia and thus harm the neighboring normal cells. In this work, a multifunctional theranostic agent (Se@SiO2@Au-PEG/DOX NCs) was exploited to solve this problem by introducing selenium, which can efficiently prevent normal cells from oxidative damage by scavenging reactive oxygen species during photothermal therapy. In addition, the Se@SiO2@Au-PEG/DOX nanocomposites (NCs) not only exhibited excellent properties of combined chemo-thermal synergistic therapy, but also showed no appreciated toxicity for the normal tissues due to the protective effect for continuous release of selenium. Thus, the fabricated Se@SiO2@Au-PEG/DOX NCs provide an integrated solution to overcome the limitations of selenium and PTT, and demonstrate great prospects as a safe and highly reliable theranostic agent.

With the in situ-generated [Pb(MCP)4]2+ (HMCP+ = 1-methyl-4-(carboxyl)pyridinium) or [M(phen)3]2+ (M = Co, Fe and Ni; phen = 1,10-phenanthroline) complexes as structural directing agents and charge-balancing ions, we solvothermally synthesized and structurally characterized four new organic−inorganic hybrid iodoplumbates. Compound K2[Pb(MCP)4]Pb3I10 (1) represents the first K+ and [Pb(MCP)4]2+ co-templated hybrid haloplumbate, and exhibits a curve-like anionic layer of [Pb3I10]n4n−. Compounds [M(phen)3]Pb2I6•CH3CN (M = Co (2), Fe (3) and Ni (4)) are isostructural phases, and feature a one-dimensional (1D) [Pb2I6]n2n− anionic chain characteristic of pyramid-like [PbI5] units. The optical property studies show that compounds 1−4 possess semiconductor behaviors with the band gaps of 1.98−2.68 eV. In addition, the title compounds exhibited interesting photoelectrical responsive properties, with the photocurrent density in the order of 1 > 3 > 2 > 4. The thermal stabilities of the title compounds 1−4, as well as the theoretical band structure and density of states (DOS) of compounds 1 and 2 have also been studied.

A series of cationic Pt(II) complexes with chelating bis‐carbene and P,P‐ or P,S‐ligands, viz . [(C^C)Pt(X^Y)][BF 4 ] 2 ( 2a‐e ), where C^C = methylenebis(3‐methyl‐1 H ‐imidazol‐1‐yl‐2‐ylidene), and X^Y = Ph 2 PCH 2 CH 2 PPh 2 (dppe) ( a ), Ph 2 P(CH 2 ) 3 PPh 2 (dppp) ( b ), 1,2‐(Ph 2 P) 2 C 6 H 4 (dppbz) ( c ), [Fe(η 5 ‐C 5 H 4 PPh 2 ) 2 ] (dppf) ( d ), and Ph 2 PCH 2 CH 2 SPh ( e ), were synthesized and structurally characterized by NMR and MS spectroscopy and by single‐crystal X‐ray diffraction analysis. Photophysical measurements showed that these compounds were non‐emissive at room temperature. However, when cooled to 77 K, compounds 2a , 2b and 2c showed weak luminescence in the near UV region with emission maxima in the 380‐395 nm range.

Density functional theory calculations have been performed to elucidate the electronic structure and bonding scenario in various carbene‐borane (LBX3) and carbene‐alane (LAlX3) compounds (X = ‐H, ‐Me, ‐Cl, ‐Ph, ‐C6F5). We have performed extended transition state (ETS) analysis to reveal the nature of the donor‐acceptor bonds (Ccarb−E; E = B, Al) and also for the assessment of the intrinsic donor‐acceptor strength in this class of compounds. Our computations suggest that the Ccarb−Al bonds in all the LAlX3 adducts have substantially higher electrostatic nature than covalent character. Conversely, the nature of the Ccarb−B bonds in LBX3 have a strong dependence on the electronic nature of both carbene and borane. Moreover, unlike alanes in LAlX3, the intrinsic Lewis acid strength of the boranes in LBX3 has a strong dependence on the electronic nature of the carbenes. We have also explored the correlation of the interaction energies (ΔEint) with various bonding parameters i.e. geometrical and Natural bond orbital (NBO) parameters of LEH3. Furthermore, natural orbital for chemical valence (NOCV) calculations are performed to have a qualitative understanding of the relative σ‐donating and π‐accepting abilities of the carbenes in LEH3. Additionally, we have investigated the abilities of carbenes to activate the B−H bonds in BH3 and pinacolborane. ETS analysis shows a strong dependence of the B−H activation barriers on the distortion energies of both carbene and borane fragments.

Organic-inorganic hybrid compounds with reversible dielectric phase transitions are a very attractive class of smart materials for their wide applications in data storage, data communication and signal sensing. Here, the piperidine ring C5H11N was introduced into the inorganic lead halide perovskite scaffold to obtain three hybrid perovskite compounds, [C5H12N]2PbCl4 (1), [C5H12N]2PbBr4 (2), and [C5H12N]PbI3 (3). When compound 2 and compound 3 feature static two-dimensional (2D) and one-dimensional (1D) perovskite structures, respectively, it is striking that compound 1 exhibits a reversible pentahedral to octahedron transformation. It undergoes an above-room-temperature dielectric phase transition at Tc ≅ 352 K, wherein the high dielectric constant is more than twice of the low dielectric constant. Structural analysis shows that 1 undergoes a phase transition from the space group Pnma of the low temperature phase (LTP) to C2/c at the high temperature phase (HTP). The phase transition originates from the order-disorder conversion of piperidinium cations. It is interesting to note that, the Pb2+ cations in the inorganic moieties change from five-coordinate at LTP to six-coordinate at HTP. The discovery of dielectric phase transition hybrid organic-inorganic lead halide perovskite materials further advances the potential application of high temperature responsive dielectric switchable materials.

Three novel isotructural Zn2Ln2 cluster complexes with carbonate bridging ligands, {Zn2Ln2(μ3-CO3)2L2(acacF6)2}•CH3OH [H2L = N,N’-dimethyl-N,N’-(2-hydroxy-3-methoxy-5-methyl-benzyl)ethylenediamine; HacacF6 = hexafluoroacetylacetone; Ln = Dy, 1; Ln = Gd, 2; Ln = Eu, 3] have been prepared by fixing the carbon dioxide in the atmosphere. Such carbonate bridging ligands may mediate ferromagnetic exchange between Ln3+ ions. The Zn2Dy2 compound (1) diplays the properties of a single molecule magnet (SMM), showing slow magnetic relaxation at 1500 Oe dc field, with an obvious larger Ueff/k value (83 K) with respect to other carbonate-bridged Zn2Dy2 SMMs (≤ 34 K) and ZnDy dinuclear SMMs derived from the same ligand H2L used in this work (≤ 36.5 K); while the Zn2Gd2 compound (2) shows a moderate magnetocaloric effect and can be looked as a potential molecular material for low temperature magnetic refrigeration.

The development and utilization of low-cost and efficient electrocatalysts for overall water splitting is of great significance for future energy supplies. Herein, the Co-doped NiCu mixed oxide films on Ni foam as a bifunctional electrocatalyst for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are synthesized by a facile solvothermal method using methanol as a reactant and followed by annealing in air, which exhibits a remarkably enhanced HER and OER activity. The well-constructed surface and porous skeleton structure with large volume provides a large number of catalytically active sites during the electrochemical reaction. Notably, CuO plays an important role in improving the catalytic activity of electrodes, meanwhile, Co doping is beneficial to increase the conductivity and activate the Ni sites at the lower overpotentials via charge transfer effect. Accordingly, the optimized CuO-NiO/Ni foam electrode exhibits comparatively low overpotential of 38 mV and 172 mV at 10 mA/cm2 for HER and OER in 1.0 M KOH, respectively. Moreover, the electrode shows excellent long-term stability for 1000 cyclic voltammetric cycles in both HER and OER. The self-assembled overall water splitting device using the electrode as both the anode and cathode achieves the current density of 10mA/cm2 at a low cell voltage 1.51V. This study is promising as a simple method for depositing multimetal mixed oxide on metal substrate as an efficient bifunctional electrocatalyst, holding great significance in future energy application.

The reactivity of the previously reported peroxo-adduct [FeIII2( μ-O)(μ-1,2-O2)(IndH)2(solv)2]2+ (1) (IndH = 1,3-bis(2-pyridyl-imino)isoindoline) has been investigated in nucleophilic (e.g., deformylation of alkyl and aryl alkyl aldehydes) and electrophilic (e.g. oxidation of phenols) stoichiometric reactions as biomimics of ribonucleotide reductase (RNR-R2) and aldehyde deformylating oxygenase (ADO) enzymes. Based on detailed kinetic and mechanistic studies we have found further evidence for the ambiphilic behaviour of the peroxo intermediates proposed for diferric oxidoreductase enzymes.

The splitting of N 2 into terminal well‐defined, terminal nitride complexes is a key reaction for nitrogen fixation at ambient conditions. In continuation of our previous work on rhenium pincer mediated N 2 splitting, nitrogen activation and cleavage upon (electro)chemical reduction of [ReCl 2 ( L 2)] ( L 2 = N(CHCHPtBu 2 ) 2 ‐ ) is reported. The electrochemical characterization of [ReCl 2 ( L 2)] and comparison with our previously reported platform [ReCl 2 ( L 1)] ( L 1 = N(CH 2 CH 2 PtBu 2 ) 2 ‐ ) provides mechanistic insight to rationalize the dependence of nitride yield on the reductant. Furthermore, the reactivity of N 2 derived nitride complex [Re(N)Cl( L 2)] with electrophiles is presented.

Lanthanides have demonstrated their outstanding properties in many fields of research including biology and medicinal chemistry. Unique luminescence and magnetic properties renders them the metals of choice for next generation theranostics that efficiently combine the two central pillars of medicine - diagnostics and therapy. Attached to targeting units, lanthanide complexes pave the way for real-time imaging of uptake and distribution as well as specific regulation of subcellular processes poor in side effects. This enables individualized treatment options of severe diseases characterized by alternated cell expression. The highly diverse efforts achieved as well as insights into the challenges that research has to face in upcoming years will be summarized in the present review.

A ligand constituted by a macrocyclic pyridinophane core having a pendant arm containing a secondary amine group linked through a methylene spacer to a pyridyl-oxadiazole-phenyl (PyPD) fluorescent system has been prepared (L). The crystal structures of [ZnL](ClO4)2 and [CuL](ClO4)2 show that the M2+ is coordinated by all the nitrogen atoms of the macrocyclic core, the secondary amine of the pendant arm and the nitrogen atom of the pyridine group of the fluorescent moiety, being this latter bond clearly weaker than the one with the pyridine of the macrocycle. Solution studies showed the formation of a highly stable Cu2+ complex of 1:1 stoichiometry, whereas with Zn2+ least stable complexes were formed and, given the right conditions, also a [Zn3L2]6+ specie was detected that was not possible to isolate in the solid state. Following Zn2+ coordination, a strong chelation enhancement of the fluorescence was observed, a behaviour that was not registered with any of the other metal cations tested.

This Frontier presents the recent developments and applications of two-dimensional (2D) amorphous transition metal oxides (TMOs) obtained by supercritial CO2. CO2 molecules can affect the crystal transformation of the layered materials and allow diffusive atomic disordering during the exfoliation process. Owing to introduction of amorphous structure, the strong localization tail states in gap of transition metal oxides can effectively promote chemical reactions. We also discuss the further challenges to be overcome for this class of supercritical CO2 and 2D amorphous materials in the future.

Correction for ‘Azamacrocycles and tertiary amines can be used to form size tuneable hollow structures or monodisperse oxide nanoparticles depending on the ‘M’ source’ by Graham E. Tilburey, et al., Dalton Trans., 2019, 48, 15470–15479.

Combination of the polyimide 6FDA-mPD (6FDA = 4,4’-hexafluoroisopropylidene diphthalic anhydride and mPD = m-phenylenediamine) and crystallites of the metal-organic frameworks (MOFs) MIL-101(Cr) or MOF-199 (HKUST-1, Cu-BTC) produces mixed-matrix membranes (MMMs) with excellent dispersion and compatibility of the MOF particles within the polymer matrix. Permeation tests of a binary CO2/CH4 (50/50) gas mixture showed a remarkable increase of CO2 permeabilities MIL-101(Cr)@6FDA-mPD and significant higher selectivities for MOF-199@6FDA-mPD. The CO2 permeability increased from 10 (neat polymer) to 50 Barrer for the 24 wt% MIL-101(Cr)@6FDA-mPD membrane (with essentially constant selectivity) due to the high pore volume of MIL-101(Cr). The CO2/CH4 selectivity increased from 54 to 89 from the neat 6FDA-mPD polymer to the 24 wt% MOF-199@6FDA-mPD membrane, apparently due to the high CO2 adsorption capacity of MOF-199.