Determination of the Assignment of Triplet States in Catacondensed Aromatic Hydrocarbons
- 15 March 1962
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 36 (6), 1608-1621
- https://doi.org/10.1063/1.1732789
Abstract
The assignment of the triplet states in benzene plays a central role in the determination of the assignment of triplet states of all the catacondensed aromatic hydrocarbons. In this paper two tests of the assignment of triplet states, based on (i) the prediction of triplet state energies in catacondensed aromatic hydrocarbons calculated using a perimeter model developed by Moffitt, and (ii) the prediction of the lowest singlet‐triplet transitions in substituted benzenes calculated using perturbation theory, are developed and applied to existing data. A number of possible benzene triplet state assignments were considered. However, the above tests are in agreement with the generally accepted assignment in which the lowest triplet state in benzene as well as the linear catacondensed aromatic hydrocarbons is assigned to 3La (in the Platt notation). The first test (i) virtually rules out all alternative assignments. The second test (ii) is consistent with the favored assignment (lowest triplet state in benzene assigned 3La) and provides fairly strong evidence against the assignment which, on theoretical grounds, is considered the next most likely assignment (lowest triplet state in benzene assigned 3Lb). More crucial experiments are proposed which should lead to an even more definitive selection of the correct assignment of the triplet states in the catacondensed aromated hydrocarbons.Keywords
This publication has 26 references indexed in Scilit:
- Changes in the Electronic Transitions of Aromatic Hydrocarbons on Chemical Substitution. I. Perturbation Theory for Substituted Cyclic PolyenesThe Journal of Chemical Physics, 1961
- Electronic Interaction in the Free-Electron Network Model for Conjugated Systems. I. TheoryThe Journal of Chemical Physics, 1956
- Theory of the Electronic Spectra and Structure of the Polyacenes and of Alternant HydrocarbonsThe Journal of Chemical Physics, 1956
- The Electronic Spectra of Cata-Condensed HydrocarbonsThe Journal of Chemical Physics, 1954
- Classification and Assignments of Ultraviolet Spectra of Conjugated Organic MoleculesJournal of the Optical Society of America, 1953
- Effect of Polar Solvents on the Absorption Frequency of n→π Electronic TransitionsThe Journal of Chemical Physics, 1952
- Experimental Determination of Even-Odd Character of Excited Electronic States of Molecules with a Center of SymmetryThe Journal of Chemical Physics, 1951
- Characterization of electronic transitions in complex moleculesDiscussions of the Faraday Society, 1950
- Classification of Spectra of Cata-Condensed HydrocarbonsThe Journal of Chemical Physics, 1949
- Molecular Orbital Treatment of the Ultraviolet Spectra of Benzene and BorazoleThe Journal of Chemical Physics, 1948