A dual approach to study the synthesis, crystal structure, thermal, optical and nonlinear optical properties of copper (II) malonate complex {(C7H8O2N)2[Cu(C3H2O4)2(H2O)2]}

A copper (II) malonate complex{[(C7H8O2N)(2)][Cu(C3H2O4)(2)(H2O)(2)]}, 1 has been synthesized and characterized by IR spectroscopy, elemental analysis, TGA/DSC and X-ray crystallography. The X-ray analysis reveals that the complex is anionic species in which copper is coordinated by six oxygen atoms having octahedral coordination geometry that is tetragonally compressed due to Jahn Teller effect. To balance the charge on the complex ion two molecules of 4-carboxybenzeneammonium ions are present as counter ions. The density functional theory methods are applied to explore the linear and nonlinear optical (NLO) properties of 1 using M06 method and 6-31G*/LANL2DZ basis set. The calculated linear molecular polarizability and third-order NW polarizability of 1 are found to be 43.98 x 10(-24) esu and 33.93 x 10(-36) esu, respectively, which interestingly better than some standard NLO molecules. To comprehend more understanding, the optical properties from molecule to material levels, we also calculated the optical properties (dielectric function, refractive index and absorption spectrum) in solid-state at bulk-level within periodic boundary conditions (PBC). The calculated optical properties show that the complex 1 possesses static dielectric function and refractive index values of 2.0 and 1.4, respectively. The absorption wavelength from 3 eV to 6 eV illustrates that the complex 1 has strong absorption and larger reflectivity values in UV region, which may be potential for using complex 1 as coating materials. It is credible that the synthesized complex 1 may possess reasonable potential for its application as optical and NLO material.