ORGN 517 |
| A series of tetraarylcyclopentadienones have been synthesized, with varying substituents on the para positions of the 2- and 5-phenyl rings. The UV-VIS spectra have been measured and correlated with specific electronic transitions calculated at the HF/6-31G* and B3LYP/6-31G* levels of theory. Three distinct absorptions are observed in the spectra of the tetraarylcyclopentadienones, which can be attributed to transitions between electronic states made up of electronic configurations involving the four frontier orbitals. In particular, the presence of phenyl substituents on the cyclopentadienone chromophore lowers the energy difference between the HOMO-1 – LUMO gap and the HOMO – LUMO+1 gap, and allows additional transitions not available to the unsubstituted cyclopentadienone. A good fit of the measured transition energies to those calculated is observed, with the general trend that electron-withdrawing substituents exhibit a bathochromic shift.
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Physical Organic Chemistry, Metal-Mediated Reactions, Asymmetric Reactions and Syntheses
8:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |
