Silver(I) complexes with heterocyclic thiones and tertiary phosphines as ligands. Part 4. Dinuclear complexes of silver(I) bromide: the crystal structure of bis[bromo-(pyrimidine-2-thione)(triphenylphosphine)silver(I)]

Mixed-ligand complexes of the formula [Ag(PPh3)(L)Br]2 were obtained by treatment of various heterocyclic thiones L {L=pyridine-2-thione (py2SH), pyrimidine-2-thione (pymtH), benz-1,3-imidazoline-2-thione (bzimtH2), benz-1,3-thiazoline-2-thione (bztztH), 1-methyl-1,3-imidazoline-2-thione (meimtH) and 5-methoxy-benz-1,3-imidazoline-2-thione (5MeObzimtH2)} with equivalent quantities of silver(I) bromide and triphenylphosphine in dry acetone. The compounds were characterized by their IR, far-IR, UV–Vis and 1H NMR spectroscopic data. The crystal structure of [Ag(PPh3)(pymtH)Br]2 was determined by single-crystal X-ray diffraction methods. The complex exhibits a planar Ag2Br2 moiety in which each of the doubly bromine-bridged Ag(I) centres is further bonded to one phosphine P and one thione S atom.