A novel Cu(II) Complex of Picolinate and 1,10-Phenanthroline: Preparation,Crystal Structure Determination,Spectroscopic Characterization and Nonlinear Optical Studies

A newly synthesized copper (II) complex of picolinic acid (also known as 2-pyridinecarboxylic acid) and 1,10-phenanthroline, [Cu(pic)₂(phen)]·H₂O, has been prepared, and its crystal structure has been fully characterized by means of X-Ray diffraction method. The spectroscopic and electronic properties have been also investigated by the applying of FT-IR, Raman and UV–Vis spectroscopies. Density functional theory (DFT) calculations have been performed by using hybrid B3LYP level in order to provide a deep understanding on the relation of the structural, spectroscopic and electronic properties with nonlinear optical properties. The intensive interactions between the bonding orbitals of donor O/N atoms and antibonding orbitals of Cu(II) lone pairs confirm crystal structure characterized with distorted octahedron. Each of the parameters such as small energy gap between HOMO and LUMO, high second order perturbation energies, elongation of the conjugated π system and d⁹ electron configuration of Cu(II) ion induce the first static hyperpolarizability (β) parameter of [Cu(pic)₂(phen)]·H₂O.