Orientation effect on distance dependent energy transfer from 1-hexadecyl pyrene to anthracene and perylene Langmuir-Blodgett layers

Abstract

Absorption and emission spectra of 1-hexadecylpyrene (HDP), 9, 10 diphenylanthracene (DPA) and perylene (PE) in stearic acid (SA) mixed Langmuir-Blodgett films have been studied and compared with that in solution. The results indicate the formation of aggregates. The energy transfer from HDP donor to DPA and PE acceptors, where the donor and acceptor could be precisely separated by inert spacers is shown to satisfy Kuhn's quadratic equation. This suggests delocalisation of donor excitation energy. This work further suggests that apart from the formation of donor aggregates, the orientation between the donor and acceptor affect the energy transfer process appreciably.