Photoinduced Charge Separation in Linked Donor-acceptor-chromophore Systems . Final Report

Book excerpt: A major experimental challenge in any study of intramolecular donor/acceptor (D/A) interactions is separating the variables which affect coupling. This is especially difficult when trying to evaluate the extent of through-bond superexchange. The systems of dinuclear complexes described below are unique in that the D/A connectivity can be varied without concomitant changes in D/A separation and relative orientation. Consequently, it has been possible to experimentally evaluate the effect of D/A linkage on coupling without introducing ambiguities from other structural changes. Furthermore, some of these systems are amenable to detailed theoretical treatment which allows quantitative comparisons between experiment and theory. A much more detailed picture of the D/A interaction is, thus, provided. Sections of this report include: unique structural aspects of[M(BBA)[sub 3]M[prime]] complexes; energy transfer in photoexcited[Ru(II)(BBA)[sub 3]Fe(II)][sup 4+] complexes; electrochemical investigation of[Fe(BBA)[sub 3]Fe][sup 4+]; optically-induced electron transfer in[Fe(II)(BBA)[sub 3]Fe(III)][sup 5+] mixed-valent complexes, where BBA=[alpha], [omega]-bisbipyridylalkane.