Structures of 2-amino-3-methylpyridinium bis(1,2–dithiooxalato-S,S')metallates(II) (M = Ni, Pd and Pt)

Abstract

Three 2-amino-3-methylpyridinium salts of planar inorganic dithiooxalato anions, (C6HaNE)E[Ni($2C202)2] (1), (C6H9Na)E[Pd(S2C202)2] (2) and (C6HaN2)E[Pt(S2C202)2] (3) have been prepared. Complexes (1) and (3) are isomorphous with (2) which crystallizes in the monoclinic space group P21/c with Z = 2 so that the anion straddles a crystallographic centre of symmetry. The crystal structure of (2) is built by mixed layers of quasi-planar complex [Pd($2C202)2] 2- anions and (C6H9N2) ÷ cations linked through electrostatic interactions, an extensive network of hydrogen bonds of types N--H...O and C--H...O, and weak 7r-~r interactions. It is clear that the packing in this type of compound is affected by the cation shape and by the hydrogen-bonding network since it is the nature of the cation rather than the metal which determines the geometry of the interactions.