Synthesis, characterization and DFT studies of complexes bearing [Re(CO)3]+ core and reactivity towards cyanide ion
Graphical abstract
Introduction
Rhenium tricarbonylchloro complexes with N∧N coordinating Schiff base ligands having d6 electronic configuration is one of the widely studied area in coordination chemistry due to its interesting photophysical properties [[1], [1](a), [1](b), [1](c), [2], [2](a), [2](b)] such as room-temperature luminescence from low-lying tunable metal to ligand charge transfer (MLCT) excited states [[3], [4], [5], [6], [6](a), [6](b), [7], [8], [9]], solar-energy conversion [[10], [10](a), [10](b), [11], [12]], OLED and sensor development [[13], [14], [15], [16], [17], [18], [44], [45], [46], [47], [48], [49], [50], [51]], and biological labeling [19,20]. These imine-based rhenium complexes having [Re(CO)3]+ core show interesting optical behavior in presence of toxic anions. It is possible to create a highly potential receptor molecule by varying ligand architecture with the photoactive rhenium(I) metal center. A few groups of researchers have shown the sensing properties of rhenium(I) complex by hydrogen bonding (NH···X) followed by deprotonation [[21], [22], [23], [24], [25]]. Anion sensing mechanism by deprotonation of O–H bond has also been reported [26]. But, anion recognition through the addition of an anion into the imine bond is rare. Cyanide ion is a very toxic anion which comes into environment through its use in pharmaceutical industries, insecticides, fertilizers, plastic manufacturing processes, extraction of metals, electroplating industries etc [[27], [28], [29], [30]]. It is necessary to replace the conventional methods of testing for cyanide such as titration, distillation, chromatography or potentiometry as they are expensive, laborious and time consuming. Therefore, there is still a need to develop more robust and less laborious testing methodologies for cyanide. In this context, the complexes of rhenium(I) are suitable. It has proven that [Re(CO)3]+ core potentially influence the imine based complex to detect cyanide ion selectively among other anions [31]. So, the main focus of this paper is the successful synthesis of two rhenium complexes with N∧N coordinating two different Schiff base ligands. We have also described the details of synthetic procedures of these mononuclear complexes and the characterization is done by various spectroscopic techniques and single crystal X-Ray diffraction study. The reactivity of these complexes towards various anions has also been studied. To describe the ground and excited state behavior of the Re(I)-diimine complexes, the contribution of the fundamental computational chemistry such as DFT/TDDFT [32] and NTO analysis is indispensable to get better insight into the geometry, electronic structure and optical properties, TDDFT calculations of several excited states have been performed.
Section snippets
Materials
Re(CO)5Cl, 2-Aminofluorene, 9-Anthraldehyde, 8-Aminoquinoline, Quinoline-2-carboxaldehyde were purchased from Sigma Aldrich. All solvents and chemicals are analytically pure. All the reactions with Re(CO)5Cl were carried out under argon atmosphere.
Physical measurements
Electrospray ionization mass spectrometry (ESI-MS) spectra were recorded on a Micromass QTOF YA 263 mass spectrometer. IR spectra were observed and obtained with a Perkin–Elmer L-0100 spectrophotometer with KBr disk. 1H NMR spectra were measured on
Synthesis
The Schiff base ligands L1 and L2 are synthesized according to the conventional method by the condensation reaction of an aldehyde and amine (Scheme 1) and are used as neutral bidentate N, N donor ligands towards Re(I) metal center. These complexes consist of two different fluorophore segments i.e. 2-Aminofluorene and 9-Anthraldehyde, which are able to show interesting photophysical properties. It is to be noted that the choice of such ligands helps us to achieve our goal in the context of
Conclusion
In summary, we have synthesized two Schiff base based ligands (L1 and L2) and two monomeric rhenium(I) complexes of these two ligands. The aim of the present work is to explore their optical properties and reactivity with various anions. The complexes are characterized by different spectroscopic techniques and X-ray crystal structure determination. This work includes investigation of the ground and excited-state geometries of both the ligands and complexes as well as the study of absorption and
Declaration of competing interest
There is no declaration of interest.
Acknowledgements
Financial assistance received from Department of Science and Technology, Govt. of West Bengal, Kolkata, India. We are also thankful to the Department of Science and Technology, New Delhi, India, for data collection on the NMR facility setup (Jadavpur University) under DST-FIST program. We also acknowledge the UGC CAS II program, Department of Chemistry, Jadavpur University, the DST-PURSE program and JU RUSA 2.0 for other facilities.
References (51)
- et al.
Synthesis, photophysics and the binding studies of rhenium(I) diiminesurfactant complexes with serum albumins: a spectroscopic and dockingstudy approach
J. Lumin.
(2019)et al.Luminescent rhenium(I) tricarbonyl complexes with pyrazolylamidino ligands: photophysical, electrochemical, and computational studies
Dalton Trans.
(2015) - et al.
Triarylamine-based hydrido-carboxylate rhenium(I) complexes as photosensitizers for dye-sensitized solar cells
Phys. Chem. Chem. Phys.
(2019)et al.Ultrafast excited-state dynamics preceding a ligand trans−cis isomerization of fac-[Re(Cl)(CO)3(t-4-styrylpyridine)2] and fac-[Re(t-4-styrylpyridine)(CO)3(2,2‘-bipyridine)]+
J. Phys. Chem.
(2005) - et al.
Excited-state dynamics in fac-[Re(CO)3(Me4phen)(L)]+
J. Phys. Chem. A
(2010) - et al.
Anion sensing by rhenium(I) carbonyls with polarized N–H recognition motifs
Inorg. Chim. Acta
(2012) - et al.
Synthesis, photophysical, and anion-sensing properties of quinoxalinebis(sulfonamide) functionalized receptors and their metal complexes
Inorg. Chem.
(2007) Hazardous waste source reduction in materials and processing technologies
J. Mater. Process. Technol.
(2001)- et al.
Time dependent density functional theory
Annu. Rev. Phys. Chem.
(2004) - et al.
Ab Initio investigation of reaction pathways for intramolecular charge transfer in dimethylanilino derivatives
J. Phys. Chem. A
(1998) - et al.
Theoretical studies on structures and spectroscopic properties of a series of novel cationic [trans-(C∧N)2Ir(PH3)2]+ (C∧N = ppy, bzq, ppz, dfppy)
J. Phys. Chem. A
(2007) - et al.
Furan/thiophene-based fluorescent hydrazones as fluoride and cyanide sensors
J. Photochem. Photobiol. A Chem.
(2019)
Photophysical and biological investigation of phenol substituted rhenium tetrazolato complexes
Dalton Trans.
Synthesis and characterization of acrylate cyanide bridged dimeric fac-rhenium(I) complex: photophysical, selective CO2 adsorption and theoretical studies
J. Organomet. Chem.
Contrasting photophysical properties of rhenium(I) tricarbonyl complexes having carbazole groups attached to the polypyridine ligand
Dalton Trans.
Luminescent rhenium(I) pyridyldiaminocarbene complexes: photophysics, anion-binding, and CO2-capturing properties
Inorg. Chem.
Synthesis, electrochemical and photophysical properties of 2, 4, 6-Tripyridyl-1, 3, 5-Triazine - bridged trinucleardiimine rhenium(I) tricarbonyl complexes
Eur. J. Inorg. Chem.
An unexpected journey from highly tunable phosphorescence to novel photochemistry of 1,2,3-triazole-based complexes
Dalton Trans.
Properties and prospects for rhenium(i) tricarbonyl N-heterocyclic carbene complexes
Chem. Commun.
Synthesis and photophysical properties of luminescent rhenium(I) and manganese(I) polypyridine complexes containing pendant 1,3,4-oxadiazole/triarylamine assemblies
Inorg. Chim. Acta
Dinuclear rhenium complex with a proton responsive ligand as a redox catalyst for the electrochemical CO2 reduction
Inorg. Chem.
Experimental and theoretical insights into spectroscopy and electrochemistry of Re(I) carbonyl with oxazoline-based ligand
Polyhedron
Dramatic alteration of 3ILCT lifetimes using ancillary ligands in [Re(L)(CO)3(phen-TPA)]n+ complexes: an integrated spectroscopic and theoretical Study
J. Am. Chem. Soc.
Photochemistry of fac-[Re(CO)3(dcbH2)(trans-stpy)]+: new insights on the isomerization mechanism of coordinated stilbene-like ligands
Inorg. Chem.
Photochemical ligand substitution reactions of fac-[Re(bpy)(CO)3Cl] and derivatives
Inorg. Chem.
A synthetic, structural, spectroscopic and DFT study of Re(I), Cu(I), Ru(II) and Ir(III) complexes containing functionalized dipyrido[3,2-a:2′,3′-c]phenazine (dppz)
Chem. Eur J.
Synthesis and characterization of luminescent rhenium(I) tricarbonyldiimine complexes with a triaryl boron moiety and the study of their fluoride ion-bbinding properties
Inorg. Chem.
Synthesis and characterization of novel rhenium (I) complexes with large Stokes shift for applications in organic electroluminescence device
J. Photochem. Photobiol., A
A simple design for strongly emissive sky-blue phosphorescent neutral rhenium complexes: synthesis, photophysics, and electroluminescent devices
Chem. Mater.
High efficient OLEDs based on novel Re(I) complexes with phenanthroimidazole derivatives
Opt. Mater.
Very high-efficiency organic light-emitting diodes based on cyclometallated rhenium (I) complex
Appl. Phys. Lett.
Cited by (6)
Synthesis and characterization of quinoxaline-based rhenium(I) organometallic compounds: Biological and computational applications
2024, Journal of Molecular StructureRhenium(I) complexes incorporating pyrene bearing N, N ligand: Luminescent based sensors for DNA
2024, Journal of Organometallic ChemistryStructural behavior of rhenium complexes in fluoride sensing: a spectroscopic and computational study
2022, Structural ChemistryAlkyl 2-benzothiazolyl sulfide ligated dirhenium complexes: Syntheses, structure and computational study of [Re<inf>2</inf>(CO)<inf>8</inf>{μ,κ <sup> 1</sup> ,κ <sup> 1</sup>–(R)SCNC<inf>6</inf>H<inf>4</inf>S}] (R = CH<inf>3</inf> and C<inf>2</inf>H<inf>5</inf>)
2022, Journal of the Iranian Chemical Society