Synthesis and solid-state structures of gold(i) complexes of diphosphines

Abstract

A series of functionalized diphosphine bisgold(I) complexes have been prepared from the corresponding diphosphine ligands Ar₄P₂ (Ar = MeC₆H₄, MeOC₆H₄, Me₂NC₆H₄) and characterized by NMR spectroscopy and APCI mass spectrometry. Single-crystal X-ray diffraction analyses were performed to study the presence and importance of unsupported aurophilic interactions for the structure formation of these compounds. In general, the complexes featured monomeric structures with an antiperiplanar arrangement of the two AuCl units. The crystal packing greatly depended on the position of the substitution pattern (ortho vs. para). While for the ortho-substituted systems (OMe and NMe₂) no ordered 3-dimensional networks were observed, the para-functionalized compounds formed regular layer structures. Here, aurophilic Au⋯Au interactions only played a minor role compared to intermolecular π⋯π interactions and hydrogen bonds.