Magnetically active coordination polymers containing VO2+ and Na+ cations linked by substituted malonic acid anions

The interaction of vanadyl sulfate VOSO4·3H2O and dimethylmalonic (H2Me2mal = = C3H6(CO2H)2), butylmalonic (H2Bumal = C4H10(CO2H)2), and cyclobutane-1,1-dicarboxylic (H2cbdc = C4H6(CO2H)2) acids with Na2CO3 at pH ∼4 in aqueous solutions gives crystals of compounds [Na4(VO)2(Me2mal)4(H2O)] n (1), {[Na6(VO)3(Bumal)6(H2O)15]· ·3H2O} n (2), and [Na2(VO)(cbdc)2(H2cbdc)(H2O)3] n (3), whose structures were determined by X-ray diffraction analysis. The formation of 3D (for 1) and 2D (for 2 and 3) polymer networks occurs in crystals of the compounds. These networks are constructed of mononuclear bis-chelate dianionic fragments [VOL2]2− (L is the corresponding dicarboxylic acid dianion) linked by the Na atoms. The magnetic properties of the obtained compounds were studied. The solid samples and solutions of complexes 1–3 were characterized by ESR spectroscopy.