Structural diversity in silver(I) and gold(I) complexes with 2,5-bis(diphenylphosphinomethyl)thiophene

Abstract

Polynuclear silver(I) and gold(I) complexes with 2,5-bis(diphenylphosphinomethyl)thiophene (dpmt) [Ag₂(µ-dpmt)₃][BPh₄]₂·2MeCN 1, [Ag₂Cl₂(µ-dpmt)] 2, [Ag₃Br₃(µ-dpmt)₂] 3, [Ag₃I₃(µ-dpmt)₂] 4, [Au₂Cl₂(µ-dpmt)] 5, [Au₂Cl₂(µ-dpmt)₂] 6, [Au₂Cl₂(µ-dpmt)₃] 7 and [(Au₂S)(µ-dpmt)] 8 were synthesised and 1, 4, 5 and 8 structurally characterised by X-ray crystallography. Complex 1 consists of a binuclear triple-helical [Ag₂(µ-dpmt)₃] cation with two three-co-ordinated Ag^I bridged by three dpmt ligands in a staggered-conformation with respect to the two AgP₃ moieties. Complex 4 has a ‘three-runged ladder’ Ag₃(µ₃-I)(µ-I)₂ unit which is bridged by two dpmt ligands above and below the trinuclear plane. Two of the Ag^I are tetrahedrally co-ordinated and one, in the middle of the structure unit, has trigonal co-ordination geometry. In 5, a pair of AuCl is bridged by one dpmt in which both Au^I exhibit linear, two co-ordinated geometry. Complex 8 has a binuclear cyclic structure with a narrow Au–S–Au angle of 86.2(1)° and short Au· · ·Au distance of 3.131(1) Å indicating a certain amount of intra-molecular Au· · ·Au interaction.