Binding of mercury(II) by N-(2-mercaptopropionyl) glycine. Synthesis, IR and NMR characterization. crystal structure of the 1 : 2 solvate of bis[N-(propionyl-2-thiolato)glycine]mercury(II) with 4-methylpyridine

Bis[N-(propionyl-2-thiolato)glycine]mercury(II), Hg[SCH(CH3)CO-NHCH2COOH](2 ), was obtained by the reaction of an aqueous solution of N-(2-mercaptoprop ionyl)glycine and mercury(II) acetate. From the 4-methylpyridine (gamma-pic oline) solution it crystallizes as a 1:2 solvate, Hg[SCH(CH3)CONHCH2COOH](2 ) . 2C(6)H(7)N, in the triclinic system, space group P (1) over bar with a = 4.810(5) Angstrom, b = 9.711(4) Angstrom, c = 15.615(8) Angstrom, alpha = 105.76(4)degrees, beta = 103.44(4)degrees, gamma = 94.01(4)degrees, Z = 1, R = 0.027. Two N-(propionyl-2-thiolato)glycine molecules are bonded centro symmetrically to mercury over sulfur atoms as mercaptide at a distance of 2 .341(2) Angstrom. Hg(mpgH)(2) molecules are connected by centrosymmetricall y related hydrogen bonds N1-H ... O3 of 2.922(5) Angstrom into chains along [100]. Each molecule also forms two hydrogen bonds O1-H ... N2 of 2.612(6) Angstrom with two gamma-picoline molecules. The structure of complexes and binding to sulfur were substantiated by H-1 and C-13 NMR spectroscopy on t he basis of mercury induced chemical shifts, H-H and C-H coupling constants and connectivities in two-dimensional homo- and heteronuclear correlated s pectra.