Synthesis and characterization of a new cyanato-N cadmium(II) Meso-arylporphyrin complex by X-ray diffraction analysis, IR, UV/vis, 1H MNR spectroscopies and TDDFT calculations, optical and electrical properties

Abstract

Herein, we have presented a new cadmium(II) pentacoordinate porphyrin complex obtained by the reaction of the [(meso‑tetra(para-methoxyphenyl)porphyrinato]cadmium(II) starting material ([Cd(TMPP)]) with an excess of potassium thiocyanate (KSCN) and crystand-222 (cryst-222) in the dichloromethane solvent leading to the coordination compound with the formula: [K(crypt-222)(H2O)][Cd(TMPP)(NCO)]·2(CH2Cl2)·0.5(C6H14)·H2O (symbolized by complex I). This species was characterized by elemental analysis, UV/Vis, FT-IR, and single crystal X-ray diffraction studies. The intermolecular interactions responsible of the cohesion of the crystal lattice of complex I were investigated using the Hirshfeld surface approach. DFT/TDDFT calculations on complex I were carried out including (i) Molecular structure optimization using the DFT/B3LYP-D3/lanl2dz level of theory, (ii) the frontier molecular orbitals (FMOs) calculations, (iii) the Mulliken charges distribution calculations, (iv) the Molecular electronic potential analysis (MEP), (v) an ab initio UV/Vis and IR calculations and (vi) the QTAIM and NCI-RDG analyses. These latter DFT/B3LYP-D3/lanl2dz calculations studies confirmed, inter alia, the strong hydrogen bond linking the NCO− axial ligand and the water molecule coordinated to the potassium counterion. Furthermore, the electrical conductance and dielectric properties of complex I were investigated shown firstly that the frequency dependence of electrical conductivity, follows the Jonscher's universal dynamic law and secondly that the obtained results have been discussed in terms of the OLPT and NSPT models, which is well adapted to our Cd(II)-porphyrin-NCO semiconductor material.