The preparation and electrochemistry of gold(III), palladium(II) and platinum(II) complexes with 2-(diphenylphosphino)thiobenzene: X-ray crystal structure of [Au(Ph2PC6H4S)(Ph2][BPh4]

Abstract

Tetrachloroaurate(/II) reacts with two equivalents of the bidentate (1-) mixed phosphinothiol ligand 2-(diphenylphosphino)benzenethiol (DPPBTH) in mildly alkaline MeOH to give a cation that can be precipitated from solution as the tetraphenylborate salt, the title complex [Au(DPPBT)2] I-BPh4] (I). The X-ray crystal structure of the complex shows it has a square planar geometry. Kz[PtCI J or PtC12 react with DPPBTH in mildly alkaline MeOH to give the 16 electron platinum(II) complex [Pt(DPPBT)2] (2), whilst reaction of Na 2 [PdC14] with DPPBTH under similar conditions gives the 16 electron palladium complex [Pd(DPPBT)z ] (3). The complexes have been studied by u.v., i.r. and n.m.r. The electrochemical behaviour of complex (I) was also investigated.

The Chemistry of Gold

“…The reaction of tetrachloroaurate(III) with two equivalents of 2-(diphenylphosphino)benzenethiol gives a cation that can be precipitated from solution as tetraphenylborate salt, [Au(2-PPh 2 C 6 H 4 S) 2 ]BPh 4 (Figure 1.73b). Surprisingly, the electrochemical behavior corresponds to a reversible single-electron transfer process and indicates that this gold(III) can be reduced to gold(II) and that the gold(II) state has reasonable stability on the electrochemical time scale [340]. The methanide carbon of [Au(C 6 F 5 )(PPh 2 CHPPh 2 Me)] reacts with carbon disulfide affording the gold(III) derivatives [Au{PPh 2 C(PPh 2 Me)C(S)S} 2 ] þ through a carbon-carbon coupling reaction.…”

Tris(pentafluorophenyl)[2-(diphenylphosphino)thiophenol-κP]gold(III) dichloromethane solvate

“…cis-[Au(CH 3 ) 2 (PPh 3 )(OPh)] 2.402 (4) A Ê (Sone et al, 1991); cis-[Au(CH 3 ) 2 {Ph 2 P(O)CH 2 PPh 2 }Cl] 2.389 (2) A Ê (Paul & Schmidbaur, 1996); [Au(2-PhNNC 6 H 4 ){3,4,5-(CH 3 O) 3 -C 6 H 2 -COCH 2 }(PPh 3 )Cl] 2.386 and 2.390 (2) A Ê (Vicente et al, 1993). Typical examples without such ligands are [Au(C 6 F 5 )(S 2 -C 6 H 4 )PPh 3 ] 2.340 (1) A Ê (Cerrada et al, 1995); [AuCl 3 (PPh 3 )] 2.335 (4) A Ê (Bandoli et al, 1973); [AuMe 3 (PPh 3 )] 2.350 (6) and 2.347 (6) A Ê (Stein et al, 1981); [Au(SC 6 H 4 PPh 2 ) 2 ]BPh 4 2.325 (4) and 2.332 (4) A Ê (Dilworth et al, 1994). The AuÐC bond lengths, 2.056 (5)±2.073 (5) A Ê , are similar to those of other tris(penta¯uorophenyl)gold(III) complexes: [Au(C 6 -F 5 ) 3 (S 2 CÐPEt 3 )] 2.037 (3) and 2.076 (4) A Ê (Uso  n et al, 1987); [("-S 2 CÐPEt 3 ){Au(C 6 F 5 ) 3 } 2 ] 2.048 (16) and 2.090 (13) A Ê (Uso  n et al, 1987); NBu 4 [{Au(C 6 F 5 ) 3 PPh 2 CHPh 2 } 2 Au] 2.057 (8) and 2.080 (8) A Ê (Ferna  ndez et al, 1995).…”

“…[Au(SC 6 H 4 PPh 2 ) 2 ]BPh 4 2.325 (4) and 2.332 (4) Å (Dilworth et al, 1994). The Au-C bond lengths, 2.056 (5)-2.073 (5) Å, are similar to those of other tris(pentafluorophenyl)gold(III) complexes: [Au(C 6 F 5 ) 3 (S 2 C-PEt 3 )] 2.037 3…”

Synthesis and coordination chemistry of thiophenol-based heterodonor ligands containing P,S, As,S and P,SAs donor atoms

“…Reaction of PSwith H[AuCl 4 ] gave the square-planar Au III complex [Au{(PS)-κ 2 S,P} 2 ] BPh 4 , which has been crystallographically characterised and shows a reversible oneelectron reduction in acetonitrile solution [124]. The crystal structure of [Au(C 6 F 5 ) 3 {(PSH)-κP}] was also reported.…”

“…Analogously to the palladium bis-chelate, [Pt{(PS)-κ 2 S,P} 2 ] was also synthesised for the first time by an S-dealkylation process [123], but its stereochemistry could not be determined. Later it was assumed to be trans [124], but in 2003 cis-[Pt{(PS)-κ 2 S,P} 2 ] was reported, as the product of a transmetallation reaction [121]. trans-[Ni{(PS)-κ 2 S,P} 2 ] has been structurally characterised in green, monoclinic [125] and brown, triclinic [126] modifications, while the cis geometry of the nickel complex could not be unequivocally confirmed by X-ray diffraction studies [121].…”