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Ab Initio Prediction of Vibrational Absorption and Circular Dichroism Spectra of Chiral Natural Products Using Density Functional Theory: α-Pinene

1997; American Chemical Society; Volume: 101; Issue: 51 Linguagem: Inglês

10.1021/jp971905a

1520-5215

F. J. Devlin, Philip J. Stephens, James R. Cheeseman, Michael J. Frisch,

Photosynthetic Processes and Mechanisms

Ab initio density functional theory (DFT) is used to analyze the vibrational unpolarized absorption and circular dichroism spectra of the chiral monoterpene, α-pinene. Large (TZ2P) basis set calculations using the hybrid functionals B3PW91 and B3LYP are in excellent overall agreement with experiment and permit the assignment of a large fraction of the fundamental frequencies. The quantitative accuracy of DFT in predicting the frequencies, dipole strengths, and rotational strengths of the fundamentals of α-pinene is documented for the B3PW91 and B3LYP functionals at both TZ2P and 6-31G* basis set levels. Hartree−Fock/self-consistent field (HF/SCF) calculations have also been carried out in parallel. The accuracy of the HF/SCF methodology is markedly inferior to that of DFT. In particular, HF/SCF predictions of the vibrational circular dichroism (VCD) spectrum of α-pinene are in very poor agreement with experiment.