Simple but effective: thermally stable Cu–ESiMe₃via NHC ligation

Abstract

A series of thermally stable N-heterocyclic copper-chalcogenolate complexes of the general formula [(IPr)Cu-ESiMe3] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; E = S, Se, Te) have been prepared from [(IPr)CuOAc] and E(SiMe3)2 at low temperature. The reaction of [(IPr)Cu-SSiMe3] with mercuric(II) acetate affords the heterometallic [{(IPr)CuS}2Hg] complex containing two (IPr)Cu-S(-) fragments to a central Hg(II).

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

“…A DFT calculation of the frontier orbitals of 1 (see ESI†) shows that the HOMO and HOMO–1 possess substantial sulfur p orbital character, suggesting that the sulfido ligand might be reactive toward electrophiles. In this vein, previously reported dicopper( i ) bridging-thiolato complexes of the form [{(IPr)Cu} 2 (μ 2 -SR)] + (R = CH 2 Ph, 17 a t Bu, 17 a SiMe 3   2a,15 ) have the appearance of the initial product that would result from formal attachment by R + to the sulfido ligand of 1 . To investigate these possibilities, the reactions of 1 with haloalkanes were studied.…”

Stable ‐ESiMe3 Complexes of CuI and AgI (E=S, Se) with NHCs: Synthons in Ternary Nanocluster Assembly

“…Compounds 1 and 2 display as lightly less distorted linear coordination geometry (C-Ag-E % 1758)c ompared to their copper analogues (C-Cu-E % 1718). [8] Expectedly, 1 and 2 display longer metal-chalcogen and metal-carbon bonds versus [(IPr)CuÀ ESiMe 3 ]. These longer metal-chalcogen andm etal-carbon distancesa re accompanied by al arger torsion angle between the pendent trimethylsilyl group and the plane defined by the imidazolin-2-ylidene ring of the carbene ligand.T he M-E-Si angles in 1 and 2 are slightly larger than those for [(IPr)CuÀSSiMe 3 ] and [(IPr)CuÀSeSiMe 3 ].…”

“…We also demonstrated that the strong bonding of IPr with Cu I would enhancet he kinetic stability first formed CuÀSÀM' complexes. [8] More recently,Z hai and coworkersr eported the synthesis of the dimetallic Cu I 2 (m-S) complex via ligation of the bulkierc arbene 1,3-bis(2,6-(diphenylmethyl)-4-methlphenyl)imidazol-2-ylidene as the ancillary ligand. [9] In this vein, access to ar ange of [(NHC)MÀESiMe 3 ]( NHC = Nheterocyclic carbene;M= Cu, Ag;E= S, Se) is of fundamental importance for the formation of new ternary metal chalcogenide nanocluster architectures.…”

A Controlled Route to a Luminescent 3 d10–5 d10 Sulfido Cluster Containing Unique AuCu2(μ3‐S) Motifs

“…[7] In as imilarv ein, ap romising, general methodf or the synthesisofternary metal-chalcogenide frameworks uses metal trimethylsilylchalcogenolates [L n M(ESiMe 3 ) y ]( L = ancillaryl igand; E = S, Se, Te ;M= metal) as precursors to ternary metal-chalcogenides. [8] With ap reformed gold-chalcogen bond, gold(I)t rimethylsilylchalcogenolate complexes would allow for the delivery of "AuÀE À "f ragments in the controlled assembly of heterometallicc halcogenide clusters via reaction with M'X y (X = Cl, OAc, OTf), resulting in the formation of AuÀEÀM' and XÀSiMe 3 . Herein, we describe our initial findings with the synthesis of the gold(I)t rimethylsilylchalcogenolates [Ph 3 PAuESiMe 3 ] 1 (E = S 1a,S e1b)a nd the preparation, photoluminescence properties and electronic structure elucidation of the mixed-metal cluster [Au 4 Cu 4 S 4 (dppm) 2 ]( 2)( dppm = bis(diphenylphosphino)-methane), prepared in good yield from 1a.C luster 2 displays rich photophysical properties, the nature of which are ad irect consequence of incorporating the two different Group 11 metals.…”

“…The cluster crystallizes as ad imethylformamide (DMF) solvate with molecular symmetry C i .T he molecule consists of ac entral Cu 4 square, linked together and shielded with four sulfide ligands that are themselves bonded to their respective Au. All gold(I) and copper(I) atoms adopt the typical distortedl inear coordination geometry.A u···Cu bond lengths between 2.8539(8) and 2.9174 (8) indicates ignificant metallophilic interactions, [1b, 4a, 10] the nature of which were probed by density functionalt heory (DFT) methods. [11] Respective shared electronn umberso btained with the population analysisb ased on occupation numbers [12] amount to 0.05, which is even less than in (hypothetical) model compound Cu-S-Au,0 .15, indicating the absence of ac ovalent chemical bond.…”