Sh. Pullen et al., Experimental verification of the through-bond mechanisms of electron transfer in bridged donor-acceptor complexes, J PHYS CH A, 103(15), 1999, pp. 2740-2743
Two rigid bischromophoric systems featuring identical donor and acceptor mo
ieties have been studied in order to directly determine the relative import
ance of through-space and through-bond mechanisms for electron-transfer rea
ctions. The two molecular systems studied have the unique feature that the
through-bond distance between any pair of atoms in the two molecules is hel
d constant while the spatial distance between the donor and acceptor is cha
nged. Time-resolved laser measurements reveal that back-electron-transfer d
ynamics following photoexcitation of the ground-state charge-transfer absor
ption band are the same in the two systems. The results provide direct evid
ence for the through-bond mechanism of electron transfer in bridged organic
donor-acceptor systems.