alpha-Bromo-p-tolunitrile: Conformational stability, vibrational spectroscopic studies, NBO analysis and thermodynamic functions based on density functional theory

作者：Janaki A; Balachandran V^*; Lakshmi A

来源：Journal of Molecular Structure, 2013, 1042: 15-24.

DOI：10.1016/j.molstruc.2013.03.040

• alpha-Bromo-p-tolunitrile
• Density functional theory
• FT-IR
• FT-Raman spectra
• Vibrational frequencies

In this work, the experimental and theoretical study on molecular structure and vibrational spectra of alpha-bromo-p-tolunitrile (alpha BpTN) are studied. The energies of possible conformers obtained from DFT theory with 6-31+G(d) and 6-311++G(d) basis sets identified the most stable conformer of alpha BpTN as C2 conformer. The differences between the observed and scaled wavenumber values of most of the fundamentals are very small in B3LYP/6-311++G(d) than B3LYP/6-31+G(d). The first hyperpolarizability (beta 0) of this novel molecular system and related properties (beta and mu) of alpha BpTN are calculated using B3LYP/6-31+G(d) and B3LYP/6-311++G(d) method on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis. The results show that charge in electron density (ED) in the sigma* and pi* antibonding orbital and second order delocalization energies conforms the occurrence of intramolecular charge transfer within the molecule. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. Finally the vibrations of C N and CH2-Br groups coupled with skeletal vibrations are also investigated.

• 出版日期2013-6-24