Synthesis and characterisation of N-coordinated pentafluorophenyl gold(i) thiazole-derived complexes and an unusual self-assembly to form a tetrameric gold(i) complex

Abstract

Treatment of [Au(C₆F₅)(SC₄H₈)] (1) (SC₄H₈ = tetrahydrothiophene or tht) with HCNC(CH₃)C(H)S, CH₃SCNC(CH₃)C(H)S, (I) or piperidine yields the neutral mononuclear imine complexes [Au(C₆F₅){NC(H)SC(H)CCH₃}] (2) and [Au(C₆F₅){NC(SCH₃)SC(H)CCH₃}] (3), or the amine complex [Au(C₆F₅){N(H)CH₂(CH₂)₃CH₂}] (4). The reaction of 1 with SCN(H)C(CH₃)C(H)S, (II) affords the thione complex [Au(C₆F₅){SCN(H)C(CH₃)C(H)S}] (5), which, in CH₂Cl₂via spontaneous intermolecular deprotonation of the thione ligand, self-assembles to an unique tetramer of Au(I), [Au{SCNC(CH₃)C(H)S}]₄ (6) containing a folded rectangle of Au-atoms with aurophlilic interactions [av. Au⋯Au distance, 3.02(4) Å and av. Au–Au–Au angle, 87(2)°]. N-coordination of the imine complexes has been confirmed by ¹⁵N NMR and the crystal structure determination of 2 which exhibits the expected linear N-coordination and intermolecular Au⋯Au [3.345(1) Å] contacts. The crystal structure of 5 shows thione S-coordination of II to the central Au atom.