Supramolecular self-organisation and conformational isomerism of a binuclear O,O′-dipropyl dithiophosphate gold(I) complex, [Au2{S2P(OC3H7)2}2]: Synthesis, 13C and 31P CP/MAS NMR spectroscopy, single-crystal X-ray diffraction study and thermal behaviour

Abstract Crystalline one-dimensional polymeric catena -poly[bis(μ 2 - O , O ′-dipropyldithiophosphato- S , S ′)digold(I)] (Au–Au) ( 1 ) was prepared and studied using 13 C and 31 P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. To elucidate the structural function of Dtph ligands in crystalline gold(I) O , O ′-dipropyl dithiophosphate, the chemical shift anisotropy parameters ( δ aniso and η ) were calculated from spinning sideband manifolds in 31 P MAS NMR spectra. A novel structure of the gold(I) compound comprises two isomeric, non-centrosymmetric binuclear molecules of [Au 2 {S 2 P(OC 3 H 7 ) 2 } 2 ] (isomers ‘A’ and ‘B’), whose four Dtph groups display structural inequivalence. In each isomeric binuclear molecule of 1 , a pair of μ 2 -bridging dipropyl Dtph ligands almost symmetrically links two neighbouring gold atoms, forming an extensive eight-membered metallocycle [Au 2 S 4 P 2 ], while the intramolecular aurophilic Au⋯Au bond additionally stabilises this central cyclic moiety. At the supramolecular level of complex 1 , intermolecular aurophilic Au⋯Au bonds yield almost linear infinite polymeric chains (⋯‘A’⋯‘B’⋯‘A’⋯‘B’⋯) n . The thermal behaviour of this compound was studied by the simultaneous thermal analysis (STA) technique (a combination of TG and DSC) under an argon atmosphere.