Coordination behavior of dimethyl pyridine-2,6-dicarboxylate towards mercury(II), cadmium(II) and chromium(III) in the solid- and gaseous state supported by CSD studies

Three complexes of dimethyl pyridine-2,6-dicarboxylate (MPC) including [Hg(MPC)Cl2] (1), [Cd(MPC)3][CdBr4] (2) and a coordination polymer, {K[Cr(PDC)2]}n (3) were prepared and identified by elemental analysis, FT-IR, Raman, 1H NMR spectroscopies and single-crystal X-ray diffraction. All coordination modes of MPC derivatives were studied by CSD and then optimized by DFT. A new formula for determination of geometry around the metals with coordination number four is presented.180