(Tnmethylphosphine)(triphenylsilyl)gold(I) and Related Compounds

Abstract

M ig u el M o n g e O ro za, A n n ette S chierb, H u b ert S ch m id b au r1 ' "' Gold-Silicon Compounds, Silyl-Gold Compounds, (Phosphine)gold(I) Complexes M ononuclear coordination compounds of the type (R3P)AuSiR'3 with R = R' = Ph and R = Me, R' = Ph have been obtained from reactions of the corresponding halide complexes (RiPjAuCl with the silyllithium reagent LiSiPh.v The fully phenylated species undergoes ligand redistribution in solution to give homoleptic ionic species. (M e.^A u S iP h i is less susceptible to this process and crystallizes from solutions as the heteroleptic complex. The crystal structure of this compound has been determined by X-ray diffraction. In the crystal lattice the molecules are not associated.

Synthesis, Structure, and Reactivity of an NHC Silyl Gold(I) Complex

“…The Au–C bond is elongated in complex 1 compared with [(IPr)­AuCl] (from 1.942(3) to 2.091(4) Å), even more than in the hydride complex [(IPr)­AuH] (2.045(3) Å) . The Au–Si bond of 1 (2.344(1) Å) is similar to those reported for phosphine silyl gold­(I) complexes (2.354(4) to 2.3629(16) Å). ,,,, The gold atom is strongly shielded by the flanking bulky Dipp groups of the NHC, likely imparting kinetic stabilization to the complex.…”

“…23 The Au-Si bond of 1 (2.344(1) Å) is similar to those reported for phosphine silyl gold(I) complexes (2.354(4) Å to 2.3629(16) Å). 9,10,29,30,33 The gold atom is strongly shielded by the flanking bulky Dipp groups of the NHC, likely imparting kinetic stabilization to the complex. Subsequently, the reactivity of the NHC silyl gold(I) complex 1 towards methyl propiolate was investigated (Scheme 3).…”

“…The commercially available complex [(IPr)­AuCl] (IPr = 1,3-bis­(2,6-diisopropyl)­phenylimidazol-2-ylidene) was chosen as the precursor. Phosphine silyl­(I) gold complexes require important steric protection at silicon to be isolated, typically SiPh 3 , Si­( t Bu)­Ph 2 , or Si­(SiMe 3 ) 3 . ,,, We surmised that the strong σ-donor character and high steric demand of IPr might enable the synthesis of an NHC silyl gold­(I) complex featuring relatively small substituents at silicon. Starting from chlorodimethylphenylsilane and lithium metal, the corresponding lithiosilane was prepared and in situ reacted with [(IPr)­AuCl] (Scheme ).…”

Electronic and steric control over Au⋯Au, C–H⋯O and C–H⋯π interactions in the crystal structures of mononuclear triarylphosphinegold(i) carbonimidothioates: R3PAu[SC(OMe)=NR′] for R = Ph, o-tol, m-tol or p-tol, and R′ = Ph, o-tol, m-tol, p-tol or C6H4NO2-4

“…For example, of the 16 77,[94][95][96][97][98][99][100][101][102][103][104][105][106][107][108] structures with the general formula Et 3 PAuX, in only six examples 77,98,99,103,104,108 are aurophilic interactions featured. In the Me 3 PAuX complexes, 20,71,[109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124] aurophilic interactions are more pervasive, being observed in the majority, i.e. 15 20,71,[109][110][111][112][113][114][115][116]…”

16 The noble metals

“…319 Treatment of the known [Au(PMePh 2 ) 2 ]-[AuCl(SiPh 3 )] with PPh 3 gave [Au(SiPh 3 )(PPh 3 )], but this very quickly converted into [Au(PPh 3 ) 2 ][Au(SiPh 3 ) 2 ]. However, using PMe 3 gave stable [Au(SiPh 3 )(PMe 3 )](crystal structure) 320. Low oxidation statesRare gold(0) complexes of some macrocyclic phosphines such as L21 have been made starting with AuGaCl 4 .…”