Synthesis and characterization of cerium(III), praseodymium(III), gadolinium(III) and erbium(III) coordination polymers with zwitterionic ligand

Four new 2D coordination polymers based on 4-carboxy-1-(4-carboxybenzyl)pyridinium bromide (H(2)cbpyBr), formulated as {[Ce(mu-cbpy)(mu(4)-cbpy)(H2O)(2)]Br center dot 7H(2)O center dot CH3CN} n (1), {[Pr(mu-cbpy)(mu(4)-cbpy)(H-2 O)(2)]Br center dot 2H(2)O center dot CH3CN}(n) (2), {[Gd(mu-cbpy)(mu-cbpy)(mu-CHOO)]center dot 4H(2)O center dot C2H5OH}(n) (3) and {[Er(mu-cbpy)(mu-cbpy)(mu-CHOO)]center dot 2H(2)O center dot C 2H5OH}(n) (4) were synthesized under solvothermal conditions and their characterizations were carried out with single crystal X-ray diffraction, IR spectroscopy, elemental and thermal analyses. Single-crystal X-ray diffraction analyses revealed that compounds 1-4 displayed 2D structures with 44.62 point symbol and sql topology. The adjacent 2D layers were extended to 3D supramolecular framework through the O-H center dot center dot center dot pi and pi center dot center dot center dot pi interactions between pyridine and phenyl rings. The cbpy ligand in compounds 1-4 adopted four different coordination modes. (C) 2021 Elsevier B.V. All rights reserved.