Synthesis and crystal structure of hexanuclear copper(I) complexes of µ₃-pyridine-2-thionate

Abstract

H-Pyridine-2-thione (C,H,NSH) reacts with [Cu( MeCN),] PF, in acetone to give an orange compound [Cu,(C,H,NS),],which crystallized in the monoclinic space group P2,/n, a = 12.257(2), b = 16.029(2), c = 9.581 (1) A, p = 108.859( 9)", and Z = 2. The single-crystal X-ray structure of the complex shows a distorted octahedral core of six copper atoms, with metal-metal distances ranging from 2.795(1) to 3.1 60( 1 ) A. Each copper has a trigonal geometry constituted by the two thiolate sulphur and one pyridine nitrogen atoms, as distinct from the common copper-thione sulphur coordination in other copper(i)-C,H,NSH complexes. The copper atom deviates highly from the S, N co-ordination plane. The reaction solution was examined by 'H n.m.r. spectroscopy, which reveals the formation of several low-molecular-weight species in the early stages of the reaction.The great interest in copper@ complexes stems in part from the unique and sometimes puzzling variation in their structural formats and chemical reactivity with changes in ligands, and also from the desire to understand the mode of action of the proteins having copper centres.2 The recent findings that copper(1) can form high nuclearity complexes have added an additional and intriguing dimension to this copper(1) chemistry. The size of copper cores ranges from two to t ~e l v e . ~ However, copper(1) complexes of high nuclearity are still sparse, and the number of examples sharply decreases with the increasing nuclearity.1 H-Pyridine-2-thione (C,H,NSH) co-ordinates as such through the sulphur atom in its most common modes of coordination (A) and (B), leading to the formation of mononuclear and binuclear complexes of copper(^)., Distinct from other transition-metal complexe~,~ where it can co-ordinate as the conjugate anion, pyridine-Zthionate (C5H4NS -), in various ways, the co-ordination of CSH,NS-to copper(1) is rare, indicating that copper(1) seems to prefer CSH4NSH. Although the reaction of C,H,NSH with copper-(I) or -(n) gives various species,, most have not been structurally characterized.We have found that the reaction of [Cu(MeCN),JPF, with CSH4NSH results in the formation of [Cu,(C,H,NS),], which has a discrete cluster structure consisting of C,H4NS-groups bonded to the c u 6 core by Cu-S-Cu and Cu-N bonds, (C). This paper concerns the preparation of this complex and its X-ray crystallographic structure, and the investigation of the reaction of C5H,NSH by 'H n.m.r. spectroscopy.

Three novel Cu6S6 cluster-based coordination compounds: synthesis, framework modulation and the sensing of small molecules and Fe3+ ions

“…The unit cell contains two independent molecules of Cu I 6 (mpymt) 6 units. Each molecule of the unit cell has a symmetry center and can be described as a distorted-octahedral core of six copper atoms.…”

Synthesis, spectral, thermal and structural characterization of a hexanuclear copper(I) cluster and a cobalt(III) complex of 1-ethyl-3-phenyl-thiourea

“…Recent work on copper(I) complexes has involved the synthesis and characterization of polynuclear complexes with bridging ligands [12]. Heterocyclic thiones, such as pyridine-2-thione [13] or 3-trimethylsilylpyridine-2-thione [14], form hexanuclear copper(I) complexes which have an interesting paddle-wheel like structure with an octahedral Cu 6 core. In these complexes each ligand, with the thione form [-NHC(@S)-], is converted to the thiolato form [-N-C(S-)-] and acts as an effectively tridentate ligand with a monodentate nitrogen atom and a bridging sulfur atom [15].…”

Mercapto derivatives of triorganotin Y,C,Y-pincer complexes: Role of Y,C,Y-chelating ligands in a new coordination mode of organotin compounds

“…After the filtration, filtrate was evaporated and the residue was characterized by 1 H and 119 Sn NMR spectroscopy as 7 according to the literature data [11]. The insoluble precipitate was characterized by 1 H NMR and IR spectroscopy as CuSPy in accordance to data found in the literature [22].…”