文摘
For the first time, the structural and optoelectronic properties of a new complex formulated as CuBrb>2b>(Cb>6b>Hb>7b>N)b>2b> (<b>1b>) [trans-dibromidobis(3-methylpyridine-κN) copper(II)] were studied by density functional theory (DFT) calculations. They are performed using B3LYP through the Gaussian 09 program and also with full potential linearized augmented plane wave (FP-LAPW) methods within the Generalized Gradient Approximation (GGA) and Hartree-Fock (HF) theory by the Wien2k package. The neutral monomeric complex participates in a variety of non-covalent interactions, including hydrogen bonding and π stacking to create a 2D coordinate plane. The binding energy value of the non-covalent interactions responsible for the crystalline network formation of <b>1b> were calculated using the method of dispersion corrected density functional theory (DFT-D). In this method, the independent smallest fragment (monomer) and subsequently the related network, including seven monomers bearing all non-covalent interactions were optimized. The results demonstrate that hydrogen bonds, especially non-conventional C–H<b>···b>Br interactions, govern the network formation along the a and c axes. It can be mentioned because of these directed interactions, increasing of charge transfer along x and z directions results in increasement of the absorption and refractive index along y and z directions, and vice versa. The results of band structure show indirectly and directly the nature of the bandgap within GGA and HF, respectively. The bandgap value of CuBrb>2b>(Cb>6b>Hb>7b>N)b>2b> is comparable to those of binary semiconductor compounds. DOSs spectra reveal that 3d Cu, 4p Br, and 2p C states play important roles in the optical transitions of the electrons. The calculated electronic absorption of the UV/Vis spectrum shows six major electron-transition bands derived from d → d (ligand field) n → n, n → π*, π → n, and σ → n MLCT and LMCT transitions. The calculated absorption spectrum of the titled complex through FP-LAPW within GGA method shows good consistency with the B3LYP/def2-TZVP/6-311+G(d,p) method. Our calculated birefringence results show that <b>1b> has capability of nonlinear optical, which can be used in the nonlinear optoelectronic devices.
