PHOTOINDUCED ELECTRON-TRANSFER IN RIGIDLY LINKED DIMETHOXYNAPHTHALENE-N-METHYLPYRIDINIUM DONOR-ACCEPTOR MOLECULES

Photoinduced electron transfer (ET) is studied in a series of novel molecules containing a dimethoxynaphthalene (DMN) donor and either a pyridine (P) or N-methylpyridinium (P-Me+) acceptor covalently linked via a rigid norbornalogous bridge (n sigma bonds in length). ET rates of the order of 10(10) s-1 were measured for the DMN-n-P-Me+ series (n = 4, 6), while no appreciable ET was observed for the DMN-n-P compound. Electronic and nuclear factors are discussed and the results rationalized in terms of Marcus-Hush and non-adiabatic ET theories.