Heterocyclic-2-thione Derivatives of Silver(I): The Methyl Substituent at N~1atom of a Imidazoline-2-thione/Imidazolidine-2-thione Alters a Dimer [Ag_2(HL)_4(PPh_3)_2](NO_3)_2 into a Monomer [Ag(HL)_2(PPh_3)](NO_3)

摘要

Reactions of silver(I) nitrate with 1,3-imidazolidine-2-thiones (L~I-NH, L~I-NMe), 1,3-imidazoline-2-thiones (L~(II)-NH, L~(II)-NMe), and that of silver(I) acetate with thiazolidine-2-thione (L~(III)-NH), or benz-imidazoline-2-thione (L~(IV)-NH) and triphenylphosphine (PPh_3) as co-ligand (1:2:2 molar ratios) in acetonitrile, acetonitrile-methanol, or acetonitrile-acetone mixtures have yielded monoand dinuclear complexes of stoichiometry: [Ag_2{μ-(L~I-NH-S)}_2(L~I-NH-S)_2(PPh_3)_2](NO_3)_2·2CH_3OH (1), [Ag(L_I-NMe-S)_2(PPh_3)](NO_3) (2), [Ag_2{μ-(L~(II)-NH-S)}_2(L~(II)-NH-S)_2(PPh_3)_2](NO_3)_2·2CH_3OH (3), [Ag(L~(II)-NMe-S)_2(PPh_3)](NO_3) (4), [Ag(L~(III)-NH-S)(L~(III)-N-S)(PPh_3)_2] (5), and [Ag(L~(IV)-NH-S)_2(PPh_3)_2](OAc)·H_2O (6). In complex 5, one thio ligand is anionic (L~(III)-N~–), whereas all other complexes have neutral thio ligands bonded to Ag~I ion. The complexes were characterized using elemental analysis, IR, ~1H and ~(31)P NMR spectroscopy and single crystal X-ray crystallography. It is interesting to note that L~I-NH and L~(II)-NH ligands formed dinuclear complexes 1 and 3 with four-coordination around each metal center, whereas the presence of a methyl group at one nitrogen atom (i.e. L~I-NMe and L~(II)-NMe) yielded mononuclear complexes 2 and 4 with three-coordination around each metal center. The ligands L~(III)-NH and L~(IV)-NH behaved differently.