Excited States of Saturated Molecules
Advances in computational technology and quantum mechanical methodology have brought accurate calculations on molecular structure and electronic spectroscopy within the realm of feasibility for moderate sized molecules. It is noteworthy, however, that in the area of excited states the great bulk of calculations have been carried out on unsaturated molecules. This can be understood in two ways. First, in the early years of quantum chemistry, prior to the availability of fast computers, planar conjugated molecules allowed the investigator to concentrate on the π-electron network, thereby, reducing the computational effort. In recent years, the natural inclination has been to re-evaluate the early results with more accurate techniques. Second, the electronic spectra of saturated molecules, especially those of acyclic alkanes, are difficult to interpret and therefore, provide less comparative information. Consequently, theoretical investigations of excited states of saturated molecules have been few. In particular, with the exception of a preliminary study of methane surfaces using a minimal basis set, ab initio calculations on alkane excited states have been limited to the vertical excitations in methane[3,4] and ethane.
Unable to display preview. Download preview PDF.
- 11.R.B. Woodward and R. Hoffmann, The Conservation of Orbital Symmetry, Academic Press, N.Y., 1970.Google Scholar
- 12.L. Salem, J.Am.Chem.Soc., 96, 3486 (1974); Science, 191, 822 (1976); W.G. Dauben, L. Salem and N.J. Turro, Accts.Chem.Res., 8, 41 (1975).Google Scholar
- 13.M.S. Gordon and J.W. Caldwell, in preparation.Google Scholar