Informative secondary chiroptics in binary molecular organogel systems for donor–acceptor energy transfer

Pyrene-doped l-glutamide-based lipidic derivatives with different alkyl lengths ( C n-g -Pyr; n = 4, 8 and 12) were newly synthesized. All of the C n-g -Pyr dissolved and showed thermotopically and lyotropically-induced excimer formations accompanied by induction of the positive Cotton effect in their CD spectra, indicating chirally ordered stacking. However, when C 4-g -Pyr and C 12-g -Pyr were mixed in a certain molar ratio, an unusual CD pattern from positive to negative ones was observed. In this study, energy transfer efficiency was investigated in a binary system of C n-g -Pyr with C 12-g -TPP. The results revealed that simple modification of the alkyl length of C n-g -Pyr enables enhancement of the energy transfer efficiency with C 12-g -TPP.