Publication Details (including relevant citation information):
S. Jeon, J. Choo, S. Kim, Y. Kwon, J.-Y. Kim, Y.-I. Lee, H. Chung;
Journal of Molecular Structure, 2002, 159, 609.
The conformational property of phthalan has been investigated using ab initio calculation and natural bond orbital (NBO) analysis methods. Geometry optimizations for the planar (C2v) and puckered (Cs) conformers have been carried out using the HF, B3LYP, and MP methods, and the results indicate that this molecule has a tiny ring-puckering barrier. This barrier appears to be in good agreement with the previous experimental result. NBO analysis shows that the tiny ring-puckering barrier is closely related to the molecular orbital interactions around the C-O bonds of the five-membered ring. The gas-phase infrared and liquid-phase Raman spectra of phthalan and 1,3-benzodioxole have been recorded and analyzed in terms of C2v symmetry. Vibrational frequency calculations using the B3LYP method have also been performed to compare with the spectroscopic data. The B3LYP frequency calculations do a reasonable job of estimating the frequencies.
Address (URL): https://dx.doi.org/10.1016/S0022-2860(01)00968-1