A new one-dimensional 3D supramolecular coordination polymer of CdII based on pyrazine and 3-nitropththalic acid: Synthesis, characterization, crystal structure, thermal analysis

Abstract

ABSTRACTA one-dimensional coordination polymer of CdII based on pyrazine (pz) and 3-nitrophthalic acid (3-nphaH2), namely poly[[diaqua bis(3-nitro-2-carboxylato-1-carboxylic acid)(µ2-pyrazine) cadmium(II)]dihydrate], {[Cd(3-nphaH)2(pz)(H2O)2]. 2H2O}n, was prepared and characterized. The asymmetric unit consists of one CdII center, two (3-nphaH)– anions, two halves of two crystallographically distinct pz ligands, two coordinated and two uncoordinated water molecules. The CdII cation is surrounded by four oxygen atoms from two (3-nphaH)– and two water molecules as well as two nitrogen atoms from two pz ligands in distorted octahedral geometry. Complicated hydrogen bonding network accompanied with N–O···π and C–O···π stacking interactions leads to formation of a 3D supramolecular network. Commonly, this kind of C–O–π and N–O···π interaction is detected in electron-rich CO/NO groups of (3-nphaH)– ligand and electron-deficient π-system of pyrazine.