SPECTROSCOPIC STUDY OF ANTHRACENE CATION TRAPPED IN BORIC-ACID GLASS

The electronic absorption spectrum of anthracene in the boric-acid glass, irradiated with uv light and x rays at room temperature, has been obtained in the region 2200-7000 A. The spectrum of the irradiated film of anthracene has been attributed to the molecular monopositive ion of anthracene. The electronic energy levels of the ion of anthracene have been calculated by FE-MO method and compared with the LCAQ-MO calculations of earlier workers. FE-MO calculations have been found to give satisfactory agreement with the experimentally observed energy levels. On the basis of these calculations, assignment of the observed bands is discussed and an attempt is made to remove the discrepancies in the assignment by earlier workers. The state of aggregation of anthracene in the boric acid along with the effect of temperature on the trapped ionic species is discussed.