Supramolecular aggregation patterns in the crystal structures of the dinuclear phosphinegold(i) thiolates, (Ph2P(CH2) 4PPh2){AuSC(OR)=NC6H4Y-4} 2 for R = Me, et or iPr and y = H, NO2 or Me: The influence on intermolecular interactions exerted by R and y

Abstract

The molecular structures of all but the R = Et/Y = NO2 derivative of the series of structures (Ph2P(CH2) 4PPh2){AuSC(OR)NC6H4Y-4} 2 for R = Me, Et or iPr and Y = H, NO2 or Me, display anti-conformations with the carbonimidothioate ligands external to the dppb (Ph2P(CH2)4PPh2) bridge. In the exceptional structure, the thiolate ligands occupy positions proximate to the dppb bridge, an observation rationalized in terms of the dictates of crystal packing. Aurophilic (Au⋯Au) interactions are not observed in their molecular or in their crystal structures. In the Y = NO2 structures, C-H⋯O interactions dominate the crystal packing leading to chain (R = Me or iPr) and layer (R = Et) motifs. Synthons of the type {Au⋯S} 2 dominate the crystal packing, leading to a chain, in one example, i.e. R = Me and Y = H. Similar {Au⋯S}2 synthons potentially appear in all the remaining structures except for R = Et and Y = H, but the Au⋯S distances are too long to be considered significant so that C-H⋯S interactions clearly dominate the crystal packing. With the exception of the layer motif found for the R = Et and Y = NO2 derivative, chain motifs, mediated by {Au⋯S}2, C-H⋯O or C-H⋯S interactions persist in the crystal structures. © The Royal Society of Chemistry 2007.