High-Coordinate Gold(I) Complexes with Dithiocarboxylate Ligands

Abstract

Ferrocene dithiocarboxylate has been introduced into the chemistry of gold(I) and copper(I). First, a modified synthesis of piperidinium ferrocene dithiocarboxylate (1) is reported. Reaction of this reagent with [Au(tht)Cl] in the presence of different phosphines resulted in monomeric, dimeric, and polymeric structures. Although gold(I) is usually two coordinate, mainly three- and four-fold coordinated compounds were obtained by using ferrocene dithiocarboxylate as ligands. The isolated compounds are [(FcCSS)Au(PPh3)2] (2) (FcCSS = ferrocene dithiocarboxylate), [(FcCSS)Au2(dppm)2] (3) (dppm = bis(diphenylphosphino)methane), and [(FcCSS)Au(dppf)]n (4) (dppf = bis(diphenylphosphino)ferrocene) [{(FcCSS)Au}2(dppp)] (5) (dppp = bis(diphenylphosphino)propane). The FcCSS ligand shows a remarkable flexible coordination mode. It coordinates either in a monodentate, a chelating, or in a metal bridging mode. In the four gold(I) complexes 2-5 four different coordination modes of the FcCSS ligand are seen. Attempts to extend this rich coordination chemistry to other coinage metals were only partly successful. [(FcCSS)Cu(PPh3)2] (6) was obtained from the reaction of piperidinium ferrocene dithiocarboxylate with [(Ph3P)3CuCl]. (57)Fe-Mössbauer spectroscopy was performed for compounds 2-4. The spectra show isomer shifts and quadrupole splittings that are typical for diamagnetic ferrocenes.

Bis(6‐methylene‐2,2′‐bipyridine)phenylphosphine—A Flexible Ligand for the Construction of Trinuclear Coinage‐Metal Complexes

“…These compounds exhibit aurophilic contacts and their photophysical properties have been investigated. In other contributions, we reported heterobimetallic compounds of gold and zirconium or iron and gold . Braunstein et al.…”

“…In other contributions,w e reportedh eterobimetallic compounds of gold and zirconium or iron and gold. [24,25] Braunstein et al also preparedr elated carbene/phosphine ligands in whicht he phosphorusa toms are directly attached to the N-heterocyclic carbene (NHC) scaffold, resulting in complexes with very short intermetallic distances. [26] Although the design of these complexes can be rationalized very well, their photophysical properties are not fully understood.…”

New π‐Extended 1,1′‐Disubstituted Ferrocenes with Thioate and Dithioate End Groups

“…In a first attempt, we followed the route devised by Roesky et al [75] and treated 1,1'-dibromoferrocene with magnesium followed by carbon disulfide, hydrochloric acid, and piperidine in order to obtain the 1,1'-disubstituted analog of 6. However, we could not isolate any defined product.…”

“…The anion of 6 was coordinated at gold by reaction with chloro (tetrahydrothiophene)gold(I) in the presence of either triphenylphosphane or bis(diphenylphosphino)methane giving complexes 7 and 8 in 58 % and 61.5 % yield, respectively (Scheme 2). [75] While the ferrocenyldithioate ligand is known, this is not the case for ferrocene-1,1'-bis(dithioates) nor for ferrocene-based molecular wires with dithioate end groups. Therefore we investigated ferrocene-based molecular wires with two dithioate end groups.…”

“…The anion of 6 was coordinated at gold by reaction with chloro(tetrahydrothiophene)gold(I) in the presence of either triphenylphosphane or bis(diphenylphosphino)methane giving complexes 7 and 8 in 58 % and 61.5 % yield, respectively (Scheme 2). [75] …”