Ortorombik metaborik asit molekülünün moleküler yapısı ve elektronik özellikleri üzerindeki konformasyonel etkinin teorik olarak incelenmesi

Abstract

In the present study, conformational analysis, Nonlinear Optical (NLO) behavior, vibrational spectra, electronic and the molecular structure of orthorhombic metaboric acid have been investigated comprehensively by using ab initio Hartree Fock (HF) and Density Functional Theory DFT at the B3LYP level with 6-311++G(d, p) basis set. The conformational analysis was performed in detail for the first time as a function of both the φ (B1-O1-H) bond angle and the ψ (O6-B1-O1-H) dihedral angle. The results of calculated potential energy curves show that the molecule has two conformers (C-I and C-II Conformer) with minimum energies in a stable form. C-I conformer is a more stable form than C-II conformer. Linear and nonlinear optical properties of conformer C-I and C-II of the orthorhombic metaboric acid molecule are examined by the determination of the electric dipole moment μ, the polarizability α, and the hyperpolarizability β both methods. The optimized molecular structures of C-I and C-II conformer of the molecule belong to C3h and Cs symmetry, respectively. The dipole moment values for conformer C-II with Cs symmetry obtained using B3LYP/6-311++G(d, p) and HF/6-311++G(d, p) methods were found to be 2.95 and 3.07 Debye, Whereas, for C-I conformer with C3h symmetry, the values obtained using the same methods are found equal (0.0 Debye). Total energy distributions (TED) were calculated to find assignments of calculated vibration modes of both conformers by using VEDA 4f program. It was observed that there is a good agreement between the experimental data in the literature and the calculated structural parameters.