Dinuclear Copper(I) and Copper(I)/Silver(I) Complexes with Condensed Dithiolato Ligands¹

Abstract

The Cu(III) complex Pr 4N[Cu{S 2C=( t-Bu-fy)} 2] ( 1) ( t-Bu-fy = 2,7-di- tert-butylfluoren-9-ylidene) reacts with [Cu(PR 3) 4]ClO 4 in 1:1 molar ratio in MeCN to give the dinuclear complexes [Cu 2{[SC=( t-Bu-fy)] 2S}(PR 3) n ] [ n = 2, R = Ph ( 2a); n = 3, R = To ( 3b); To = p-tolyl]. The analogue of 2a with R = To ( 2b) can be obtained from the reaction of 3b with 1/8 equiv of S 8. Compound 2b establishes a thioketene-exchange equilibrium in solution leading to the formation of [Cu 4{S 2C=( t-Bu-fy)} 2(PTo 3) 4] ( 4b) and [Cu 2{[SC=( t-Bu-fy)] 3S}(PTo 3) 2] ( 5b). Solid mixtures of 4b and 5b in varying proportions can be obtained when the precipitation of 2b is attempted using MeCN. The reactions of 1 with AgClO 4 and PPh 3, PTo 3 or PCy 3 in 1:1:4 molar ratio in MeCN afford the heterodinuclear complexes [AgCu{[SC=( t-Bu-fy)] 2S}(PR 3) 3] [R = Ph ( 6a), To ( 6b), Cy ( 6c)]. Complex 6c dissociates PCy 3 in solution to give the bis(phosphine) derivative [AgCu{[SC=( t-Bu-fy)] 2S}(PCy 3) 2] ( 7c), which undergoes the exchange of [M(PCy 3)] (+) units in CD 2Cl 2 solution to give small amounts of [Cu 2{[SC=( t-Bu-fy)] 2S}(PCy 3) 2] ( 2c) and [Ag 2{[SC=( t-Bu-fy)] 2S}(PCy 3) 2] ( 8c). Complexes 6a and b participate in a series of successive equilibria in solution, involving the dissociation of phosphine ligands and the exchange of [M(PCy 3)] (+) units to give 2a or 3b and the corresponding disilver derivatives [Ag 2{[SC=( t-Bu-fy)] 2S}(PR 3) 2] [R = Ph ( 8a), To ( 8b)], followed by thioketene-exchange reactions to give [AgCu{[SC=( t-Bu-fy)] 3S}(PR 3) 2] [R = Ph ( 9a), To ( 9b)]. Complexes 9a and b can be directly prepared from the reactions of 1 with AgClO 4 and PPh 3 or PTo 3 in 1:1:3 molar ratio in THF. The crystal structures of 3b, 6b, 6c, 7c, and 9a have been solved by single-crystal X-ray diffraction studies and, in the cases of 7c and 9a, reveal the formation of short Ag...Cu metallophilic contacts of 2.8157(4) and 2.9606(6) A, respectively.

Synthesis and Characterization of a Series of New Luminescent NHC‐Coordinated AuI–AgI Tetra‐ and Polymetallic Complexes Containing Benzoate‐Bridged Ag2 Dimers

“…Comparative views of their cores are presented in Figure 6. In 3, the asymmetric unit consists of one-half of the tetrametallic Au 2 Ag 2 core associated to one-half of an Ag 2 (CO 2 Ph) 2 …”

“…In the acetonitrile polymer, the d 10 -d 10 metal-metal separations between the alternating Au I and Ag I centers are small and range from 2.8633(6) to 2.9239(6) Å. The intermetallic angles deviate significantly from linearity and range from 135.20 (2) to 175.37(3)°. Replacement of the acetonitrile solvent with benzonitrile produces a similar type of polymer, but the metal-metal separations are much more uniform and range from 2.833(1) to 2.835(1) Å.…”

“…It is well established [1][2][3] that closed-shell, d 10 metal ions often exhibit attractive interactions. These interactions, although weaker than ionic bonds, are stronger than simple van der Waals interactions.…”

“…[15] One such species is derived from the precursor 1-methyl-3-(2-pyridinyl)-1H-imidazolium hexafluorophosphate, [H(CH 3 impy)]PF 6 . It was observed [15b] (Scheme 1) before that the Au complex of this ligand, when treated with AgBF 4 in presence of a nitrile solvent such as CH 3 CN, produced polymeric species {[AuAg(CH 3 impy) 2 (S)](BF 4 ) 2 } n , where S stands for solvent. In these mixed-metal, one-dimensional polymers, the Au I centers are bonded to two carbene moieties, and the Ag I centers are coordinated to two alternating pyridyl groups and a solvent molecule.…”

Shedding Light on the Photochemistry of Coinage-Metal Phosphorescent Materials: A Time-Resolved Laue Diffraction Study of an AgI–CuI Tetranuclear Complex

“…5,9–17,19–41 A number of examples of short argentophilic contacts down to 2.637(1) Å, found in [Et 4 N] 2 [(Ag-(Sn 2 B 11 H 11 )bipy) 2 ], 41 have been reported. 19,21,42–44 In particular, heterometallic complexes 9,12,27,29,32,45–49 have recently attracted interest because of their efficient luminescence.…”