A combined theoretical and experimental study of chelidamate cadmium (II) complex, [Cd2(dpa)2(chel)2]⋅2[Cd(dpa)(chel)]⋅6H2O

•The geometries of the monomeric and dimeric units were optimized with HF and DFT-B3LYP method using SDD basis set.•The available experimental results were compared with theoretical data.•The seven-coordinate Cd (II) ions display a distorted monocapped trigonal prismatic coordination environment.•The absorption band at 313 nm for the tree solvents corresponds to the HOMO → LUMO+1 transition.

A new chelidamate complex of Cd (II) ion, [Cd2(dpa)2(chel)2]⋅2[Cd(dpa)(chel)]⋅6H2O [(chel: chelidamate or 4-hydroxypyridine-2,6-dicarboxylate, dpa: di (2-picolyl)amine)] was synthesized and characterized by spectroscopic (UV–Vis and FT-IR spectroscopy) and structural (single-crystal X-ray diffraction) methods. Quantum chemical calculations were carried out by using Hartree Fock (HF) and Density Functional Theory (DFT)/B3LYP methods Stuttgart/Dresden (SDD) basis set. The asymmetric unit of the title compound contains two symmetry unrelated monomeric units, one dimeric unit and six water molecules of crystallization. The geometries around the Cd (II) metal centers in the units can be described as distorted octahedral for the monomeric units and distorted monocapped trigonal prism for the dimeric unit. The electronic structure of the complex was calculated using time dependent DFT (TD-DFT) method with polarizable continuum model (PCM). Molecular stability and bond strength were investigated by applying natural bond orbital analysis (NBO). The computed frequencies were compared with experimental frequencies.

Graphical abstractA detail of the coordination environment around the dimeric unit, illustrating the monocapped trigonal-prismatic geometry.Figure optionsDownload full-size imageDownload as PowerPoint slide