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-mercaptopropionyl)glycine and mercury(II) acetate. From the 4-methylpyridine (γ-picoline) solution it crystallizes as a 1:2 solvate, Hg[SCH(CH3)CONHCH2COOH]2 ⋅ 2C6H7N, in the triclinic system, space group P1̅ with a = 4.810(5) Å, b = 9.711(4) Å, c = 15.615(8) Å, α = 105.76(4)°, β = 103.44(4)°, γ= 94.01(4)°, Z = 1, R = 0.027. Two N-(propionyl-2-thiolato)glycine molecules are bonded centrosymmetrically to mercury over sulfur atoms as mercaptide at a distance of 2.341(2) Å. Hg(mpgH)2 molecules are connected by centrosymmetrically related hydrogen bonds N1−H⋅⋅⋅O3 of 2.922(5) Å into chains along [100]. Each molecule also forms two hydrogen bonds O1−H⋅⋅⋅N2 of 2.612(6) Å with two γ-picoline molecules. The structure of complexes and binding to sulfur were substantiated by 1H and 13C NMR spectroscopy on the basis of mercury induced Chemical shifts, H−H and C−H coupling constants and connectivities in twodimensional homo- and heteronuclear correlated spectra