Aminkomplexe des Golds, Teil 8: Zwei Pyridinderivate des Gold(I)-thiocyanats [1] / Amine Complexes of Gold, Part 8: Two Pyridine Derivatives of Gold(I) Thiocyanate

Abstract

Abstract The reaction between (tht)AuCl (tht = tetrahydrothiophene) and KSCN leads to a mixture possibly consisting of gold(I) thiocyanate and [Au(tht)2]+ [Au(SCN)2]-. This can be treated with pyridine to give the ionic derivative [Au(py)2]+ [Au(SCN)2]- (1), for which the structures of two polymorphs were determined. Orthorhombic polymorph 1a (space group Pbcn, Z = 4) consists of infinite chains of alternating cations and anions with all gold atoms lying on a twofold axis, whereas triclinic polymorph 1b (space group P1̅, Z = 2) contains isolated tetranuclear units cation···anion···anion···cation with inversion symmetry. In both patterns the gold atoms are linked by short aurophilic contacts. Attempts to recrystallize 1b from dichloromethane-diethyl ether led to small quantities of tetrapyridinium bis(dithiocyanatogold(I)) sulfate (2), (pyH)4[Au(SCN)2]2(SO4), which was identified by crystal structure analysis. The cations are associated with the sulfate ions by classical hydrogen bonds; aurophilic interactions between the anions lead to dimers, which further associate to chains by Au···S contacts.