INTRA-MOLECULAR ELECTRONIC-ENERGY TRANSFER IN 1,8(6',7'-DIOXODODECAMETHYLENE) PHENANTHRENE

The absorption spectrum of 1,8 (6′, 7′-dioxododecamethylene)phenanthrene (I) is composed of a superposition of the phenanthrene and biacetyl chromophores. The band at 340 nm corresponds to the phenanthrene absorption and that at 450 nm can be assigned to the biacetyl chromophore. Excitation at 337.1 nm results in emission from both chromophores. The lifetime of the phenanthrene moiety in I is 10 ns compared to 60 ns in phenanthrene. This is indicative of an intramolecular energy transfer process. Two-photon excitation of the biacetyl chromophore results in emission from the phenanthrene moiety. The mechanism for these energy transfer processes is probably of the Dexter type. © 1979.