Synthesis and Structure of Zn(II) Complexes with Cyclobutane-1,1-Dicarboxylic Acid Anions and Calcium and Barium Cations

New zinc(II) compounds with cyclobutane-1,1-dicarboxylic acid (H2Cbdc) anions and calcium [CaZn(Cbdc)2(H2O)3]n (I) and barium [BaZn(Cbdc)2(H2O)2]n (II) cations were obtained. According to X-ray diffraction data (CIF files CCDC nos. 2055176 (I), 2055177 (II)), compounds I and II are coordination polymers in which zinc atoms are connected by bridging and chelating-bridging acid dianions to form 2D architectures with a square lattice topology. Alkaline earth metal atoms do not affect the dimensionality of compound packing.