Biomimetic electron transfer using low energy excited states: A green perylene-based analogue of chlorophyll a

We have prepared a green chromophore, 1,7-bis(pyrrolidin-1-yl)-3,4:9,10-perylene-bis(dicarboximide) (5PDI), that exhibits photophysical and redox properties similar to those of chlorophyll a (Chl a), yet unlike Chl a, it can be easily functionalized and incorporated into a wide variety of biomimetic electron donor−acceptor systems. The N,N‘-dicyclohexyl derivative (5PDI) absorbs strongly (e = 46 000 M-1 cm-1) at 686 nm in toluene and fluoresces at 721 nm with a 35% quantum yield. Additionally, 5PDI is both oxidized and reduced in CH2Cl2 at 0.57 V and −0.76 V vs SCE, respectively, making it a facile electron donor or acceptor. Rodlike covalent electron donor−acceptor molecules 5PDI−PI, 5PDI−NI, and 5PDI−PDI were prepared by linking the imide group of the 5PDI donor to pyromellitimide (PI), 1,8:4,5-naphthalenebis(dicarboximide) (NI), and 1,7-bis(3,5-di-tert-butylphenoxy)-3,4:9,10-perylene-bis(dicarboximide) (PDI) acceptors via an N−N bond. Following femtosecond laser excitation of 5PDI, 5PDI−PI, 5PDI−NI, an...