Strukturen zweier Salze des Bis(thioharnstoff)gold(I)-Kations

Abstract

Abstract Attempts to isolate the compound (tu2Au)SCN 1 (tu=thiourea), first reported in 1949, at first led to [(tu)2Au]2SO4·CH3OH 2 after crystallization from methanol-petroleum ether. Crystallization from isopropanol led to the required compound 1. The crystal structure analysis of 1 confirmed its ionic nature, (tu2Au)+ SCN−. The tu ligands are mutually trans (torsion angle C–S···S–C 175.4(2)°), and the entire cation is approximately planar (r.m.s. deviation 0.08 Å). Eight classical hydrogen bonds connect the residues to form layers parallel to the bc plane at x≈⅛, ⅜, ⅝ and ⅞; the layers are connected by aurophilic contacts, which link the cations to form chains parallel to the a axis. In the structure of compound 2 the S=C groups are synclinal to each other; two NH2 groups are connected via a bifurcated hydrogen bonding system to a sulfate oxygen, forming a ring of graph set R 2 1 ( 10 ) . ${\rm{R}}_2^1(10).$ In a complex three-dimensional packing, the cations are connected by various interactions to form layers parallel to the ac plane at y≈½, whereas the sulfates are the centres of hydrogen-bonded double layers on both sides of the mirror plane at y≈¾. The structure contains a convincing example of a hydrogen bond to a gold centre.