Synthesis and structures of dinuclear palladium complexes with 1,3-benzimidazolidine-2-thione and 1,3-imidazoline-2-thione

Abstract

The synthesis and structures of dinuclear palladium complexes with 1,3-benzimidazolidine-2-thione (bzimtH) and 1,3-imidazoline-2-thione (imtH) are reported, namely, bis(μ-1H-benzimidazole-2-thiolato)-κ2 N 3:S;κ2 S:N 3-bis[cyanido(triphenylphosphine-κP)palladium(II)], [Pd2(C7H5N2S)2(CN)2(C18H15P)2] or [Pd2(μ-N,S-bzimtH)2(CN)2(PPh3)2] (1), and bis(μ-1H-imidazole-2-thiolato)-κ2 N 3:S;κ2 S:N 3-bis[cyanido(triphenylphosphine-κP)palladium(II)] acetonitrile 0.58-solvate, [Pd2(C3H3N2S)2(CN)2(C18H15P)2]·0.58C2H3N or [Pd2(μ-N,S-imtH)2(CN)2(PPh3)2]·0.58C2H3N (2). The compound [Pd2(μ-N,S-bzimtH)2(CN)2(PPh3)2] is located on a crystallographic twofold axis while [Pd2(μ-N,S-imtH)2(CN)2(PPh3)2]. 0.58(C2H3N) contains two partially occupied acetonitrile solvent molecules with occupancies of 0.25 and 0.33. In both of these compounds, the anionic bzimtH− and imtH− ligands coordinate through N,S-donor atoms in a bridging mode, covering four coordination sites of two metal centers and other two sites are occupied by two PPh3 ligand molecules. Finally, the remaining two sites of two metal centers are occupied by cyano groups, abstracted by the metals from the solvent during reaction. In the packing of the 1,3-benzimidazolidine- 2-thione and 1,3-imidazoline-2-thione complexes, there are intramolecular π–π interactions involving the thione moiety as well as an N—H...N hydrogen bond linking the thione and cyano ligands. In addition, in 2, as well as the π–π interaction involving the thione moieties, there is an additional π–π interaction involving one of the thione moieties and an adjacent phenyl ring from the triphenylphosphine ligand. There are also C—H...N interactions between the imidazoline rings and the acetonitrile N atoms.