Diaquabis(dimethyl sulfoxide)bis(3,5-dinitrobenzoato)zinc(II) and the synthesis of the Cu, Ni and Co analogs

In order to model processes of chemisorption in organic salts formed between dinitrobenzoic acids (DNBH) and secondary amines (R2NH), a series of compounds of composition [M-II(3,5-DNB)(2)(DMSO)(2)(H2O)(2)] (where M-II is Zn, Cu, Ni or Co, 3,5-DNB is the 3,5-dinitrobenzoate ion, and DMSO is dimethyl sulfoxide) have been prepared. In diaquabis(dimethyl sulfoxide) bis(3,5-DNB) zinc(II), [Zn(C7H3N2O6)(2)(C2H6OS)(2)(H2O)(2)], the 3,5-DNB ions and molecules of DMSO are monodentate ligands that are coordinated to the Zn atom through their O atoms. These ligands, together with two molecules of water, form a slightly distorted octahedral coordination environment for the Zn atom, which lies on a center of symmetry.