Reactions of a gold(i) thiolate complex [Au(Tab)2]2(PF6)2 (Tab = 4-(trimethylammonio)benzenethiolate) with diphosphine ligands

Abstract

Reactions of a gold(I) thiolate complex [Au(Tab)₂]₂(PF₆)₂ (Tab = 4-(trimethylammonio)benzenethiolate) with equimolar 1,2-bis(diphenylphosphine)ethane (dppe), 1,3-bis-(diphenylphosphine)propane (dppp) or 1,4-bis-(diphenylphosphine)butane (dppb) in MeOH–DMF–CH₂Cl₂ gave rise to three polymeric complexes [Au₂(Tab)₂(dppe)]₂(PF₆)₄·2MeOH (1·2MeOH), [Au₂(Tab)₂(dppp)]Cl₂·0.5MeOH·4H₂O (2·0.5MeOH·4H₂O), and [Au₄(μ-Tab)₂(Tab)₂(dppb)](PF₆)₄·4DMF (3·4DMF), respectively. Analogous reaction of 1 with dppb in DMF/C₂H₄Cl₂ produced one tetranuclear complex [Au₂(μ-Tab)(Tab)₂]₂Cl₄·2DMF·4H₂O (4·2DMF·4H₂O). Complexes 1–4 were characterized by elemental analysis, IR spectra, UV-vis spectra, ¹H and ³¹P{¹H} NMR and single crystal X-ray analysis. Compounds 1 and 2 consist of [Au(Tab)]₂ dimeric fragments that are bridged by dppe or dppp ligands to form a 1D linear chain extending along the a axis. For 3, each [Au₄(Tab)₂(μ-Tab)₂] fragment is linked by a pair of dppb ligands to afford another 1D chain extending along the c axis. For 4, the four [Au(Tab)]⁺ fragments are linked by two Au–Au bonds and two doubly bridging Tab ligands to form a {[Au(Tab)]₄(μ-Tab)₂} chair-like cyclohexane structure. Hydrogen-bonding interactions in 2 and 4 lead to the formation of interesting 2D hydrogen-bonded networks. The luminescent properties of 1–4 in solid state were also investigated.