Original Articles: 2013 Vol: 5 Issue: 5
Conformational stability, vibrational spectral studies, HOMO-LUMO and NBO analyses of 2-bromo-1-Indanol based on quantum chemical calculations
Indanol is most stable molecule it’s stabilized by internal hydrogen bonding, which exists between the hydroxyl hydrogen and the π–cloud of the benzene ring. A comprehensive ab initio calculation using the DFT/ 6-31+G (d) level theory showed that 2-bromo1-Indanol can exist in eight possible conformations, which can interchange through the OH group on the five-membered ring. Density functional theory calculations were used to predict the vibrational frequencies and to help in normal mode assignments. The spectral intensities indicate that, at 90°C, 82% of the molecules exist in its most stable form with the intramolecular hydrogen bonding. Furthermore, a natural bond orbitial analysis was performed describing each hydrogen bond as donor-accepter interaction. The Fourier transform infrared spectra (4000–400 cm-1) and the Fourier transform Raman spectra (3500–100 cm-1) of the title molecule in the solid space have been recorded. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The calculated ESP contour map shows the electrophilic and nucleophilic region of the molecule.