The electronic and molecular structures of some new Cu(II) complexes with tripodal amine ligands: DFT studies

The new anticancer complexes with tripodal ligands formulated [Cu(pmea)Cl] (1) (pmea = Bis[(2-pyridyl)methyl]-2-(2-pyridyl)]ethylamine), [Cu(pmap)Cl] (2) (pmap = Bis[2-(2-pyridyl)ethyl]-(2-pyridyl)]methylamine), and [Cu(bpdmpz)Cl] (3) (bpdmpz = bis[((2-pyridylmethyl)-di(3,5-dimethyl-1H-pyrazolyl)methyl)]amine) have been used for calculations at B3LYP/LANL2DZ/6-311+G (d, p) level of density functional theory (DFT)[1]. Their CIFs with CCDC (1) 1491458 (2) 1491471, and (3) 1558493 show that they crystallizes in triclinic, monoclinic, and monoclinic systems with P1, P21/c, and C2/c space groups, respectively[2]. The structural comparison of the mentioned complexes could followed through their physicochemical properties such as, electronic transmission in UV-Visible spectroscopy, chemical shift of metal center NMR, total energy, and frontier molecular orbitals (FMOs) energy. The relation of structure especially ligand electron donating ability with these properties has been discussed. The calculated electronic absorption spectra confirm the experimental data with electron-transition bands of intra-ligand charge transfer (ILCT) with π → π*, metal to ligand charge transfer (MLCT) with π* → n (d), and ligand to metal charge transfer (LMCT) with π →n(d) character for 1, 2, and 3, respectively.