Copper Ion Mediated Selective Cleavage of C–S Bond in Ferrocenylthiosemicarbazone Forming Mixed Geometrical [(PPh3)Cu(μ-S)2Cu(PPh3)2] Having Cu2S2 Core: Toward a New Avenue in Copper–Sulfur Chemistry

Synthesis of a Series of a Few Hydrosulfide Complexes of Cu(I). A μ3-SH-Bridged Rare Cubane-like Tetramer Showing Efficient Catalytic Activity toward Azide-Alkyne Cycloaddition

A cubane-like tetranuclear hydrosulfido complex of Cu(I), [Cu₄(SH)₄(PPh₃)₄] (1), has been synthesized by the reaction of Cu(NO₃)₂·3H₂O, NaSCOPh, and Cu(PPh₃)₂NO₃ and characterized structurally. Complex 1 represents the first example of crystallographically characterized μ₃-SH-bridged cubanoid hydrosulfide. By direct reactions of [(PPh₃)₂Cu(NO₃)] and NaSH, neutral hydrosulfide complexes [Cu(SH)(PPh₃)₂]·C₆H₆ (2), [Cu₂(SH)₂(PPh₃)₃] (3), and [Cu₂(SH)₂(PPh₃)₄] (4) have also been synthesized and structurally characterized. Complex 2 is monomeric with a terminal hydrosulfide ligand. The other two, 3 and 4, are μ₂-SH-bridged unsymmetrical and symmetrical dinuclear complexes, respectively. In the symmetric one (4), both Cu(I) ions are tetrahedrally coordinated while in the unsymmetric one (3), one Cu(I) ion is tetrahedral and the other one has a trigonal-planar coordination geometry. The catalytic activity of a hydrosulfido complex in a "click" azide-alkyne cycloaddition reaction has been explored for the first time, and complex 1 is found to be an efficient catalyst for the regioselective synthesis of glycoconjugate triazoles.

Synthesis and spectral characterizations of water soluble Cu(ii) complexes containing N-heterocyclic chelates: cell-proliferation, antioxidant and nucleic acid/serum albumin interactions

Water soluble N-heterocyclic copper(ii) complexes were synthesized, characterized and studied their DNA/protein binding interactions, antioxidation and antiproliferative potentials. The complex 4 found to be better than other complexes.

Unpredicted formation of copper(ii) complexes containing 2-thiophen-2-yl-1-thiophen-2-ylmethyl-1H-benzoimidazole and their most promising in vitro cytotoxicity in MCF-7 and HeLa cell lines over cisplatin

An in situ reaction of CuCl₂·2H₂O, o-phenylenediamine, thiophene-2-carbaldehyde and sodium azide in methanol afforded complex 1a.

Coinage metal coordination chemistry of stable primary, secondary and tertiary ferrocenylethyl-based phosphines

Ferrocene-based phosphines constitute an important auxiliary ligand in inorganic chemistry. Utilizing the (ferrocenylethyl)phosphines (FcCH2CH2)3-nHnP (Fc = ferrocenyl; n = 2, 1; n = 1, 2; n = 0, 3) the synthesis of a series of coordination complexes [(FcCH2CH2)3-nHnPCuCl]4 (n = 2, 1-CuCl; n = 0, 3-CuCl), [(FcCH2CH2)2HPCuCl] (2-CuCl), {[(FcCH2CH2)H2P]2AgCl}2 (1-AgCl), [(FcCH2CH2)2HPAgCl] (2-AgCl), [(FcCH2CH2)3PAgCl]4 (3-AgCl), [(FcCH2CH2)3PM(OAc)]4 (M = Cu, 3-CuOAc M = Ag, 3-AgOAc), [(FcCH2CH2)3-nHnPAuCl] (n = 1, 2-AuCl; n = 0, 3-AuCl), via the reaction between the free phosphine and MX (M = Cu, Ag and Au; X = Cl, OAc), is described. The reaction between the respective phosphine with a suspension of metal-chloride or -acetate in a 1 : 1 ratio in THF at ambient temperature affords coordinated phosphine-coinage metal complexes. Varying structural motifs are observed in the solid state, as determined via single crystal X-ray analysis of 1-CuCl, 3-CuCl, 1-AgCl, 3-AgCl, 3-CuOAc, 3-AgOAc, 2-AuCl and 3-AuCl. Complexes 1-CuCl and 3-CuCl are tetrameric Cu(i) cubane-like structures with a Cu4Cl4 core, whereas silver complexes with primary and tertiary phosphine reveal two different structural types. The structure of 1-AgCl, unlike the rest, displays the coordination of two phosphines to each silver atom and shows a quadrangle defined by two Ag and two Cl atoms. In contrast, 3-AgCl is distorted from a cubane structure via elongation of one of the ClAg distances. 3-CuOAc and 3-AgOAc are isostructural with step-like cores, while complexes 2-AuCl and 3-AuCl reveal a linear geometry of a phosphine gold(i) chloride devoid of any aurophilic interactions. All of the complexes were characterized in solution by multinuclear (1)H, (13)C{(1)H} and (31)P NMR spectroscopic techniques; the redox chemistry of the series of complexes was examined using cyclic voltammetry. This class of complexes has been found to exhibit one reversible Fe(ii)/Fe(iii) oxidation couple, suggesting the absence of electronic communication between the ferrocenyl units on individual phosphine ligands as well as between different phosphines on the polymetallic cores.

Synthesis, structure, and reactions of a copper-sulfido cluster comprised of the parent Cu2S unit: {(NHC)Cu}2(μ-S)

The first CuI2(μ-S) complex, {(IPr*)Cu}₂(μ-S) (IPr* = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene), has been synthesized, and its structure has been characterized crystallographically.

The synthesis of the first CuI2(μ-S) complex, {(IPr*)Cu}₂(μ-S) (IPr* = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene; 1), has been accomplished via three synthetic routes: (1) salt metathesis between (IPr*)CuCl and Na₂S; (2) silyl-deprotection reaction between (IPr*)Cu(SSiMe₃) and (IPr*)CuF; and (3) acid–base reaction between (IPr*)Cu(SH) and (IPr*)Cu(O^tBu). The X-ray crystal structure of 1 exhibits two two-coordinate copper centers connected by a bent Cu–S–Cu linkage. Application of these synthetic routes to analogous precursors containing the sterically smaller ligand IPr (1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidene), in place of IPr*, resulted in the formation of a transient product proposed as {(IPr)Cu}₂(μ-S) (2), which decomposes quickly in solution. The instability of 2 probably results from the insufficient steric protection provided by IPr ligands to the unsaturated Cu₂(μ-S) core; in contrast, 1 is stable both in solution and solid state for weeks. The nucleophilic sulfido ligand in 1 reacts with haloalkyl electrophiles (benzyl halides and dibromoalkanes) with formation of C–S bonds, affording (IPr*)Cu(SCH₂Ph) and cyclic thioethers, respectively.

A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation

A new azo-complex [(L)Cu(II)(NO3)] [L = (E)-3-(pyridin-2-yldiazenyl)naphthalen-2-ol (HL)], was prepared via a one-pot synthetic method at 60 °C and was structurally characterized by IR, EA, PXRD and single crystal X-ray diffraction. In addition, TGA studies indicated that the complex was stable in air. The redox properties were determined by cyclic voltammetry, which revealed that the complex could be utilized as a catalyst for water oxidation under mild conditions. Subsequently, the complex was employed as a catalyst to take part in water oxidation reaction in the presence of a Ce(IV) salt utilized as an oxidant at pH 11 in PBS (Phosphate Buffered Saline) solution. The results suggested that the catalyst exhibited a high stability and activity toward water oxidation reaction under these conditions with an initial TOF of 4.0 kPa h(-1). Calculation methodology was performed to study the mechanism of the reaction, which revealed that in this catalytic process, the initial oxidation of Cu(II) to Cu(III) occurred by the formation of an intermediate "Cu(III)-O-O-Cu(III)". The formation of this intermediate, resulted in a release of oxygen and closing of the catalytic cycle.

Nickel(ii) and copper(ii) complexes constructed with N2S2 hybrid benzamidine–thiosemicarbazone ligand: synthesis, X-ray crystal structure, DFT, kinetico-catalytic and in vitro biological applications

We report nickel(ii) and copper(ii) complexes containing the benzamidine–thiosemicarbazone ligand together with DFT, enzyme kinetics and in vitro biological applications such as DNA/BSA affinities and anticancer properties.

Unprecedented formation of organo-ruthenium(ii) complexes containing 2-hydroxy-1-naphthaldehyde S-benzyldithiocarbazate: synthesis, X-ray crystal structure, DFT study and their biological activities in vitro

We report the unprecedented formation of ruthenium(ii) complexes containing dithiocarbazate ligand, together with their DFT and biological studies.

A cyclic tetranuclear cuboid type copper(ii) complex doubly supported by cyclohexane-1,4-dicarboxylate: molecular and supramolecular structure and cyclohexane oxidation activity

A rare isolated tetranuclear 3d complex with a single metal CDC cuboid cage. It catalyzes cyclohexane peroxidative oxidation without any promoter.