Synthesis, molecular structure, spectroscopic characterization and dielectric properties of new cobalt(II) meso-tetraphenylporphyrin-based coordination complex

Abstract

In this work, a new 5,10,15,20-tetrakis[4-(benzoyloxy)phenyl]porphyrin (H2TPBP)-based cobalt(II) complex involving DABCO ligand [CoII(TPBP)(DABCO)2] (1), has been prepared and characterized. The single crystal structure of (1) was obtained with a space group of P-1 and this study provides further information about the structure of the octahedral complex. This six-coordinate complex is close to a perfect plane in H2TPBP, and the molecules are interconnected through C–H⋯O and C–H⋯π interactions to form 1D and 3D architectures. Spectroscopic characterizations such as Mass spectroscopy, elemental analysis, infrared, and 1HNMR in solution demonstrate the contiguity of the paramagnetic Co(II) center. The photophysical properties were investigated by UV–visible absorption and emission spectroscopies. The dielectric properties such as dielectric constant (ε′), dielectric loss (ε″), conductivity (σ), real (M′) and imaginary part (M″) of dielectric modulus were investigated as a function of temperature and frequency. The impedance analysis was carried out using Cole-Cole plots to elucidate the electrical conduction mechanism.