Synthesis, X-Ray crystal structure, photophysical characterization and nonlinear optical properties of the unique manganese complex with picolinate and 1,10 phenantroline: toward the designing of new high NLO response crystal

Abstract

The first manganese complex of picolinic acid (also known as 2-pyridinecarboxylic acid) and 1,10 phenantroline has been synthesized, and its structure has been fully characterized by means of X-Ray diffraction method as well as FT-IR, Raman and UV-vis spectroscopies. In order to provide a deep understanding about the relation among the nonlinear optical properties, structural, spectroscopic and electronic behaviors, density functional theory (DFT) calculations have been performed by using hybrid B3LYP level. The intensive interactions between the bonding orbitals of donor O/N atoms and anti bonding orbitals of Mn(II) lone pairs confirm the X-Ray diffraction results. Each of,the conditions such as small energy gap between HOMO and LUMO, high energy second order perturbation interaction, elongation of conjugated pi system and high spin Mn(II) ion induce the first static hyperpolarizability (beta) parameter of investigated complex. The beta parameter for [Mn(pic)(2)(phen)]center dot H2O complex has been found to be approximately 22 times higher than p-nitroaniline. (C) 2016 Elsevier Ltd. All rights reserved.