INTRAMOLECULAR EXCITATION TRANSFER IN 1,4-DIMETHOXY-5,8-METHANO-6,7-EXO-[FLUORENE-9'-SPIRO-1''-CYCLOPROPANE]NAPHTHALENE

The recent reports1,2 that no excitation transfer takes place between the chromophores in the title compound (I) are unexpected from theory and past experience, and, indeed upon investigation we found entirely different results. Because of the nature of the absorption spectrum of I, it is dangerous to consider excitation transfer within that molecule, at least in the very weak coupling limit. However, assuming that such considerations are legitimate our measurements of the emissions from I and proper models are consistent with a scheme which requires very efficient singlet excitation transfer from the p-methoxybenzene group to the fluorene moiety in I. © 1969, American Chemical Society. All rights reserved.