Synthesis, Molecular, and Supramolecular Structures of Two Azide-Bridged Cd(II) and Cu(II) Coordination Polymers

Two 1D coordination polymers were synthesized by reaction of two ligands, 2-amino-4-picoline (2A4Pic) and quinoline-6-carboxylic acid (Qu-6-COOH) with metal (II) nitrate (M = Cd Cu) in the presence azide as a linker. The complexes [Cd(2A4Pic)2(N3)2]n; (1) [Cu(Qu-6-COO)(N3)(H2O)]n; (2) isolated single crystals their X-ray structures revealed polymeric structure. Due to symmetry considerations, asymmetric formula is half [Cd(2A4Pic)2(N3)2] unit for 1 one [Cu(Qu-6-COO)(N3)(H2O)] 2. In complex 1, Cd(II) hexa-coordinated 2A4Pic molecules four μ(1,1) units. Hence, CdN6 environment has slightly distorted octahedral geometry. 2, Cu(II) three different ligands (Qu-6-COO¯, H2O N3¯) where all are connectors between crystallographically related sites. Additionally, 2 CuN2O4 both complexes, polymer arrays connected N…H hydrogen bonds π–π stacking interactions. Based on Hirshfeld analysis, percentages contacts 43.1 27.4% respectively, while %C...C 5.6 9.3%, respectively. Analysis Cu-N, Cu-O, Cd-N using DFT calculations showed predominantly closed-shell interactions little covalent characters. negatively charged ligand groups found compensate positive charge central ion larger extent than electrically neutral ligands.