Synthesis,crystal structure and biological activities of dehydroacetic acid complexes of Ru(II) and Ru(III) containing PPh3/AsPh3

A series of Ru(II) and Ru(III) complexes of the types [RuX(CO)(EPh₃)₂L] (X = H, E = P; X = Cl, E = P or As) and [RuX₂(EPh₃)₂L] (X = Cl, E = P or As; X = Br, E = As, L = monoanion of dehydroacetic acid) have been synthesized in order to explore their biological activities, such as DNA-binding and antibacterial activity. The complexes were characterized by analytical and spectroscopic techniques. The crystal and molecular structure of [RuCl₂(AsPh₃)₂(L)] has been determined by single crystal XRD. The cyclic voltammograms of the complexes in acetonitrile displayed either quasi-reversible or irreversible redox couples based on the metal centre. The ligand, dehydroacetic acid (DHA) and its metal complexes were tested against five pathogenic bacteria. Absorption titration and cyclic voltammetric studies revealed that the complexes interact with Herring Sperm ds DNA through different binding modes to different extents.     

Ruthenium(III) complexes of amine-bis(phenolate) ligands as catalysts for transfer hydrogenation of ketones

Twelve ruthenium(III) complexes bearing amine-bis(phenolate) tripodal ligands of general formula [Ru(L¹–L³)(X)(EPh₃)₂] (where L¹–L³ are dianionic tridentate chelator) have been synthesized by the reaction of ruthenium(III) precursors [RuX₃(EPh₃)₃] (where E = P, X = Cl; E = As, X = Cl or Br) and [RuBr₃(PPh₃)₂(CH₃OH)] with the tripodal tridentate ligands H₂L¹, H₂L² and H₂L³ in benzene in 1:1 molar ratio. The newly synthesized complexes have been characterized by analytical (elemental and magnetic susceptibility) and spectral methods. The complexes are one electron paramagnetic (low-spin, d⁵) in nature. The EPR spectra of the powdered samples at RT and the liquid samples at LNT shows the presence of three different ‘g’ values (g_x ≠ g_y ≠ g_z) indicate a rhombic distortion around the ruthenium ion. The redox potentials indicate that all the complexes undergo one electron transfer process. The catalytic activity of one of the complexes [Ru(pcr-chx)Br(AsPh₃)₂] was examined in the transfer hydrogenation of ketones and was found to be efficient with conversion up to 99% in the presence of isopropanol/KOH.     

Novel oxorhenium complexes with 2-(2′-hydroxyphenyl)-2-benzothiazolinato ligand: X-ray studies,spectroscopic characterization and DFT calculations

The [ReOX₂(hbt)(EPh₃)] (X = Cl, Br; E = As, P) chelates have been prepared in the reactions of [ReOX₃(EPh₃)₂] complexes (X = Cl, Br; E = P, As) with 2-(2′-hydroxyphenyl)-2-benzothiazole (hbtH) in acetone. From the reactions of [ReOX₃(PPh₃)₂] with hbtH two kind of crystals [ReOX₂(hbt)(PPh₃)] · MeCN and [ReOX₂(hbt)(PPh₃)] with different arrangement of halide ions (cis and trans) were isolated, whereas the [ReOX₃(AsPh₃)₂] oxocompounds react with hbtH to give only cis-halide isomers. The complexes were structurally and spectroscopically characterised. The electronic structures of both [ReOBr₂(hbt)(PPh₃)] isomers have been calculated with the density functional theory (DFT) method. The TDDFT/PCM calculations have been employed to produce a hundred of singlet excited-states starting from the ground-state geometry optimized in the gas phase of cis- and trans-halide isomers of [ReOBr₂(hbt)(PPh₃)] and the UV–Vis spectra of these complexes have been discussed on this basis.     

Ru(III) complexes containing 3,5-pyrazole dicarboxylic acid and triphenylphosphine/triphenylarsine: Synthesis, characterization and catalytic activity

New hexa-coordinated Ru(III) complexes of the type [Ru(H₂Pzdc)(EPh₃)₃X₂] have been synthesized by reacting 3,5-pyrazole dicarboxylic acid (H₃Pzdc) with the appropriate starting complexes [RuX₃(EPh₃)₃] (where X = Cl or Br; E = P or As). The ligand behaves as a bidentate monobasic chelate. All the complexes have been characterized by analytical and spectroscopic (IR, electronic and EPR) data. Single-crystal X-ray analysis of the complex [Ru(H₂Pzdc)(PPh₃)₂Cl₂]·C₆H₆·C₂H₅OH revealed that the coordination environment around the ruthenium center consists of an NOP₂Cl₂ octahedron. The planar ligand occupies the equatorial position along with two chlorine atoms, while the triphenylphosphine groups occupy the axial positions. The electrochemical behavior of the new complexes was studied using cyclic voltammetry. The new mononuclear ruthenium complexes are capable of acting as catalysts for the oxidation of alcohols.     

Ruthenium(II) carbonyl complexes of dehydroacetic acid thiosemicarbazone: Synthesis, structure, light emission and biological activity

The reaction of [RuHCl(CO)(B)(EPh₃)₂] (where E = As, B = AsPh₃; E = P, B = PPh₃, py, pip, or mor) and dehydroacetic acid thiosemicarbazone (abbreviated as H₂dhatsc where H₂ stands for the two dissociable protons) in benzene under reflux afford a series of new ruthenium(II) carbonyl complexes containing dehydroacetic acid thiosemicarbazone of general formula [Ru(dhatsc)(CO)(B)(EPh₃)] (where E = As, B = AsPh₃; E = P, B = PPh₃, py, pip or mor; dhatsc = dibasic tridentate dehydroacetic acid thiosemicarbazone). All the complexes have been characterized by elemental analyses, FT-IR, UV-Vis, and ¹H NMR spectral methods. The thiosemicarbazone of dehydroacetic acid behaves as dianionic tridentate O, N, S donor and coordinates to ruthenium via phenolic oxygen of dehydroacetic acid, the imine nitrogen of thiosemicarbazone and thiol sulfur. In chloroform solution, all the complexes exhibit metal-to-ligand charge transfer transitions (MLCT). The crystal structure of one of the complexes [Ru(dhatsc)(CO)(PPh₃)₂] (1) has been determined by single crystal X-ray diffraction which reveals the presence of a distorted octahedral geometry in the complexes. All the complexes exhibit an irreversible oxidation (Ru^III/Ru^II) in the range 0.76-0.89 V and an irreversible reduction (Ru^II/Ru^I) in the range −0.87 to −0.97 V. Further, the free ligand and its ruthenium complexes have been screened for their antibacterial and antifungal activities. The complexes show better activity in inhibiting the growth of bacteria Staphylococcus aureus and Escherichia coli and fungus Candida albicans and Aspergillus niger. These results made it desirable to delineate a comparison between free ligand and its ruthenium complexes.     

Synthesis,crystal structure and catalytic activity of ruthenium(II) carbonyl complexes containing ONO and ONS donor ligands

Diamagnetic ruthenium(II) complexes of the type [Ru(L)(CO)(B)(EPh₃)] [where E = As, B = AsPh₃; E = P, B = PPh₃, py (or) pip and L = dibasic tridentate ligands dehydroacetic acid semicarbazone (abbreviated as dhasc) or dehydroacetic acid phenyl thiosemicarbazone (abbreviated as dhaptsc)] were synthesized from the reaction of [RuHCl(CO)(B)(EPh₃)₂] (where E = As, B = AsPh₃; E = P, B = PPh₃, py (or) pip) with different tridentate chelating ligands derived from dehydroacetic acid with semicarbazide or phenylthiosemicarbazide. All the complexes have been characterized by elemental analysis, FT-IR, UV–Vis and ¹H NMR spectral methods. The coordination mode of the ligands and the geometry of the complexes were confirmed by single crystal X-ray crystallography of one of the complexes [Ru(dhaptsc)(CO)(PPh₃)₂] (5). All the complexes are redox active and are monitored by cyclic voltammetric technique. Further, the catalytic efficiency of one of the ruthenium complexes (5) was determined in the case of oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide.     

Oxorhenium(V) complexes with quinoline-2-carboxylate ligand. X-ray structure of [ReOCl2(quin-2-c)(PPh3)] and [ReOBr2(quin-2-c)(AsPh3)] complexes: DFT and TD-DFT calculations for [ReOCl2(quin-2-c)(PPh3)]

Novel [ReOX₂(quin-2-c)(EPh₃)] complexes (X = Cl, Br; E = As, P; quin-2-c = quinoline-2-carboxylate ion) have been prepared by treatment of [ReOX₃(EPh₃)₂] with quinoline-2-carboxylic acid in acetone at room temperature. All the complexes were characterised by IR, UV–Vis spectroscopy and elemental analysis. The crystal and molecular structures have been determined for [ReOCl₂(qiun-2c)(PPh₃)] (1) and [ReOBr₂(qiun-2c)(AsPh₃)] (4). The electronic structure of 1 has been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of 1 have been calculated with the time-dependent DFT method.     

Ruthenium(III) mediated C-H activation of azonaphthol: Synthesis, structural characterization and transfer hydrogenation of ketones

Treatment of [RuCl₃(PPh₃)₃] with 1-(arylazo)naphthol ligands in benzene under reflux afford air-stable new organoruthenium(III) complexes with general composition [Ru(an-R)Cl(PPh₃)₂] (where, R = H, Cl, CH₃, OCH₃, OC₂H₅) in fairly good yield. The 1-(arylazo)naphtholate ligands behave as dianionic tridentate C, N, O donors and coordinates to ruthenium through phenolic oxygen, azo nitrogen and ortho carbon generate two five-membered chelate rings. The composition of the complexes have been established by analytical (elemental analysis and magnetic susceptibility measurement) and spectral (FT-IR, UV-Vis, EPR) methods. The complexes are paramagnetic (low-spin, d⁵) in nature and in dichloromethane solution show intense d-d transitions and ligand-to-metal charge transfer (LMCT) transitions in the visible region. The solution EPR spectrum of complex [Ru(an-CH₃)Cl(PPh₃)₂] (3) in dichloromethane at 77 K shows rhombic distortion around the ruthenium ion with three different ‘g’ values (g_x ≠ g_y ≠ g_z). The single crystal structure of the complex [Ru(an-OCH₃)Cl(PPh₃)₂] (4) has been characterised by X-ray crystallography, indicates the presence of a distorted octahedral geometry in these complexes. All the complexes exhibit one quasi-reversible oxidative response in the range 0.60-0.79 V (Ru^IV/Ru^III) and two quasi-reversible reductive responses (Ru^III/Ru^II; Ru^II/Ru^I) within the range −0.50 to −0.62 V and −0.93 to −0.98 V respectively. The formal potential of all the couples correlate linearly with the Hammett constant of the para substituent in arylazo fragment of the 1-(arylazo)naphtholate ligand. Further, the catalytic efficiency of one of the ruthenium complexes (4) was determined for the transfer hydrogenation of ketones with an excellent yield up to 99% in the presence of isopropanol/KOH.     

Synthesis, structure, catalytic transfer hydrogenation and biological activity of cyclometallated ruthenium(III)2-(arylazo)phenolate complexes

A series of mononuclear organoruthenium complexes of the type [RuX(PPh₃)₂(L)] (X = Cl or Br; L = 2-(arylazo)phenolate ligand) have been synthesized from the reaction of five 2-(arylazo)phenol ligands with ruthenium(III) precursors, viz. [RuCl₃(PPh₃)₃] and [RuBr₃(PPh₃)₂(CH₃OH)] in benzene under reflux. In all these reactions, the 2-(arylazo)phenolate ligand replaces one triphenylphosphine molecule, two chlorides or bromides and one methanol from the precursors leading to five-membered cyclometallated species. The 2-(arylazo)phenol ligands behave as dianionic tridentate C, N, O donors and coordinated to ruthenium by dissociation of the phenolic proton and the phenyl proton at the ortho position of the phenyl ring. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-Vis and EPR spectral data. These complexes are paramagnetic and shows intense d-d and charge transfer transitions in chloroform. The solution EPR spectrum of the complex 7 in dichloromethane at 77 K shows rhombic distortion around the ruthenium ion. The structural conformation of the complex 1 has been carried out by X-ray crystallography. The redox behavior of the complexes has been investigated by cyclic voltammetry and the potentials are observed with respect to the electronic nature of substituents (R) in the 2-(arylazo) phenolate ligands. These complexes catalyze transfer hydrogenation of benzophenone to benzhydrol with up to 99.5% in the presence of i-prOH/KOH. Further, these complexes have shown great promise in inhibiting the growth of both Gram +ve and Gram −ve bacteria, viz. Staphylococcus aureus NCIM 2079 and Escherichia coli NCIM 2065 and fungus Candida albicans NCIM 3102.     

Mononuclear ruthenium(III) complexes containing chelating thiosemicarbazones: Synthesis,characterization and catalytic property

Mononuclear ruthenium(III) complexes of the type [RuX(EPh₃)₂(L)] (E = P or As; X = Cl or Br; L = dibasic terdentate dehydroacetic acid thiosemicarbazones) have been synthesized from the reaction of thiosemicarbazone ligands with ruthenium(III) precursors, [RuX₃(EPh₃)₃] (where E = P, X = Cl; E = As, X = Cl or Br) and [RuBr₃(PPh₃)₂(CH₃OH)] in benzene. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV–vis and EPR spectral data. These complexes are paramagnetic and show intense d–d and charge transfer transitions in dichloromethane. The complexes show rhombic EPR spectra at LNT which are typical of low-spin distorted octahedral ruthenium(III) species. All the complexes are redox active and display an irreversible metal centered redox processes. Complex [RuCl(PPh₃)₂(DHA–PTSC)] (5) was used as catalyst for transfer hydrogenation of ketones in the presence of isopropanol/KOH and was found to be the active species.     

p-Tolylimido rhenium(V) complexes – Synthesis,X-ray studies,spectroscopic characterization and DFT calculations

The p-tolylimido rhenium(V) complexes [Re(p-NC₆H₄CH₃)X₃(EPh₃)₂] (X = Cl, Br; E = As, P) and [Re(p-NC₆H₄CH₃)Cl₂(hmpbta)(PPh₃)]·MeCN have been synthesized and characterized spectroscopically and structurally. The electronic spectra of [Re(p-NC₆H₄CH₃)Cl₃(PPh₃)₂] and [Re(p-NC₆H₄CH₃)Cl₂(hmpbta)(PPh₃)](Hhmpbta-2-(2′-hydroxy-5′-methylphenyl)benzotriazole) were investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ. Additional information about bonding between the rhenium atom and p-tolylimido ligand in the complexes [Re(p-NC₆H₄CH₃)Cl₃(PPh₃)₂] and [Re(p-NC₆H₄CH₃)Cl₂(hmpbta)(PPh₃)] was obtained by NBO analysis.     

Catalytic oxidation and C–C coupling reactions of new ruthenium(III) Schiff base complexes containing PPh<Subscript>3</Subscript> or AsPh<Subscript>3</Subscript> co-ligands

New mononuclear ruthenium(III) Schiff base complexes of the type [RuX₂(EPh₃)(L)] (X = Cl or Br; E = P or As; L = monobasic tridentate Schiff base derived from o-aminophenol or o-aminothiophenol with ethylacetoacetate or ethylbenzoylacetate) have been synthesized. The Schiff base ligands chelate to ruthenium through O, N, and O/S by dissociation of the phenolic proton/thiophenolic proton forming chelate rings. These complexes have been characterized by physico-chemical and spectroscopic methods. Cyclic voltammetric data of all the complexes showed Ru(III)/Ru(IV) oxidation and Ru(III)/Ru(II) reduction within the range of 0–1.5 V and 0 to −1.5 V with respect to Ag/AgCl, respectively. The complexes were tested as catalysts in the oxidation of alcohols using molecular oxygen at ambient temperature, and also in C–C coupling reactions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis, spectral characterization, catalytic and antibacterial studies of new Ru(III) Schiff base complexes containing chloride/bromide and triphenylphosphine/arsine as co-ligands

A new Ru(III) Schiff base complexes of the type [RuX(EPh₃)L] (X = Cl/Br; E = P/As; L = dianion of the Schiff bases were derived by the condensation of 1,4-diformylbenzene with o-aminobenzoic acid/o-aminophenol/o-aminothiophenol in the 1:2 stoichiometric ratio) have been synthesized from the reactions of [RuX₃(EPh₃)₃] with appropriate Schiff base ligands in benzene in the 2:1 stoichiometric ratio. The new complexes have been characterized by analytical, spectral (IR, electronic, ¹H, ¹³C NMR and ESR), magnetic moment and electrochemical studies. An octahedral structure has been tentatively proposed for all these new complexes. All the new complexes have been found to be better catalyst for the oxidation of alcohols using molecular oxygen as co-oxidant at ambient temperature and aryl–aryl coupling reactions. These complexes were also subjected to antibacterial activity studies against Escherichia coli, Aeromonas hydrophilla and Salmonella typhi.     

Novel oxorhenium complexes with 2-(2′-hydoxy-5′-methylphenyl)benzotriazolato ligand. X-ray studies,spectroscopic characterization and DFT calculations

The [ReOCl₂(hmpbta)(AsPh₃)] · MeCN, [ReOBr₂(hmpbta)(AsPh₃)] · MeCN, [ReOCl₂(hmpbta)(PPh₃)] · MeCN, [ReOBr₂(hmpbta)(PPh₃)] · MeCN, and [ReBr₂(hmpbta)(PPh₃)] · MeCN complexes have been prepared in the reactions of [ReOX₃(EPh₃)₂] (X = Cl, Br; E = P, As) with 2-(2’-hydoxy-5′-methylphenyl)benzotriazole in molar ratio 1:1. All the compounds were structurally and spectroscopically characterized. The electronic structure of [ReOCl₂(hmpbta)(AsPh₃)] has been calculated with the density functional theory (DFT) method. The TDDFT/PCM calculations have been employed to produce a hundred of singlet excited-states starting from the ground-state geometry optimized in the gas phase, and the UV–Vis spectrum of [ReOCl₂(hmpbta)(AsPh₃)] has been discussed on this basis. The paper reports also X-ray structure and DFT calculations for the disubstituted [ReOCl(hmpbta)₂] chelate.     

Novel hydridotris(pyrazolyl)borate ruthenium(II) complexes containing the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane: Synthesis and evaluation of DNA binding properties

A series of half-sandwich ruthenium(II) complexes containing κ³(N,N,N)-hydridotris(pyrazolyl)borate (κ³(N,N,N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ³(N,N,N)-Tp}(PPh₃)_2−n(PTA)_n] (n = 2, X = Cl (1), n = 1, X = Cl (2), I (3), NCS (4), H (5)) and [Ru{κ³(N,N,N)-Tp}(PPh₃)(PTA)L][PF₆] (L = NCMe (6), PTA (7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ³(N,N,N)-Tp}(m-PTA)₂][CF₃SO₃]₂ (8) and [RuX{κ³(N,N,N)-Tp}(PPh₃)(m-PTA)][CF₃SO₃] (X = Cl (9), H (10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated.     

Spectrometric,catalytic, and antimicrobial studies of mononuclear Ru(III) Schiff-base complexes

A series of air stable low spin Ru(III) complexes, [RuX₂(EPh₃)(L)] (where X = Cl or Br; E = P or As; L = monobasic tridentate Schiff-base ligand), have been synthesized by reacting [RuCl₃(PPh₃)₃], [RuCl₃(AsPh₃)₃], and [RuBr₃(PPh₃)₃] with the Schiff base in 1 : 1 molar ratio in benzene. These complexes have been characterized by elemental analysis, FT-IR, UV-Vis, and EPR spectroscopy together with magnetic susceptibility. The redox behaviors of the complexes have been investigated by cyclic voltammetric technique. Catalytic efficiency of the ruthenium complexes was determined for aryl–aryl coupling and the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of molecular oxygen as co-oxidant. All complexes were screened for antibacterial activity.     

Incorporation of a tripodal ligand with a (N,O,O)-donor set into a new family of nickel and cobalt spin clusters

The reaction of Ni(OAc)₂, NiX₂ (X = Cl, Br) or CoCl₂ with the proligand 2-amino-2-methyl-1,3-propanediol (ampdH₂) affords a new family of tetranuclear complexes. The syntheses of [Ni₄(OAc)₄(ampdH)₄] (1) and [M₄X₄(ampdH)₄] (M = Ni, X = Cl, 2; M = Ni, X = Br, 3; M = Co, X = Cl, 4) are reported, together with the single crystal X-ray structures of 1, 2 and 4 and the magnetochemical characterization of 1, 3 and 4. Each member of this family of complexes displays a low symmetry structure that incorporates a {M₄O₄} core unit based on a distorted cubane. Magnetic measurements reveal ferromagnetic exchange interactions for 1, 3 and 4. These give rise to S = 4 ground state spins for the tetranuclear Ni complexes and an anisotropic effective S′ = 2 ground state for the Co complex.     

Synthesis and structural characterisation of five copper(I) and silver(I) complexes with 2-aminopyridine (2-APy), [Cu(μ-Cl)(2-Apy)(PPh3)]2, [Ag(μ-X)(2-Apy)(PPh3)]2 (X = Cl,Br), [Ag(μ-ONO2)(2-Apy)(EPh3)]2 (E = P,As)

Five new copper(I)/silver(I) complexes containing 2-aminopyridine, [Cu(μ-Cl)(2-Apy)(PPh₃)]₂(1), [Ag(μ-Cl)(2-Apy)(PPh₃)]₂(2), [Ag(μ-Br)(2-Apy)PPh₃)]₂(3), [Ag(μ-ONO₂)(2-Apy)(PPh₃)]₂(4), [Ag(μ-ONO₂)(2-Apy)(AsPh₃)]₂(5) have been synthesised for the first time. Complexes 1–5 are obtained by the reactions of MX (MX = CuCl for 1; M = Ag for 2–5; X = Cl, Br for 2–3; X = NO₃ for 4–5) with the monodentate ligands EPh₃ (E = P for 1–4; E = As for 5) and 2-Apy in the molar ratio of 1:1:2 in the mixed solvent of CH₂Cl₂ and MeOH. Complexes 1–5 are characterised by IR and X-ray diffraction. In 1–5, chloride, bromide and nitrate ions bridge two metal atoms to form dinuclear complexes containing the parallelogram cores M₂X₂ (M = Cu, Ag).     

Ruthenium(II) chalconate complexes: Synthesis, characterization, catalytic, and biological studies

A series of new hexa-coordinated ruthenium(II) carbonyl complexes of the type [RuCl(CO)(EPh₃)(B)(L)] (E = P or As; B = PPh₃, AsPh₃ or Py; L = 2′-hydroxychalcones) have been prepared by reacting [RuHCl(CO)(EPh₃)₂(B)] (E = P or As; B = PPh₃, AsPh₃ or Py) with 2′-hydroxychalcones in benzene under reflux. The new complexes have been characterized by analytical and spectral (IR, electronic, ¹H, ³¹P and ¹³C NMR) data. Based on the above data, an octahedral structure has been assigned for all the complexes. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant and also found efficient catalyst in the transfer hydrogenation of ketones. The antifungal properties of the complexes have also been examined and compared with standard Bavistin.     

Studies on ruthenium(III) chalcone thiosemicarbazone complexes as catalysts for carbon–carbon coupling

New six-coordinate ruthenium(III) complexes [RuX(EPh₃)₂(L)] (X = Cl or Br; E = P or As; L = chalcone thiosemicarbazone) have been prepared by reacting [RuX₃(EPh₃)₃] (X = Cl or Br; E = P or As) with chalcone thiosemicarbazones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (IR, electronic, mass, and EPR) data. The redox behavior of the complexes has also been studied. Based on the above data, an octahedral structure has been assigned for all the complexes. The new complexes exhibit catalytic activity for carbon–carbon coupling reactions.