Excitation Energy Transfer between a First Generation Dendrimer and a Pyrene Derivative in Langmuir−Blodgett Multilayers

Abstract

A first generation dendrimer D1 was placed onto defined surfaces to study the excitation energy transfer between D1 as donor molecule and a pyrene containing polymer 213 as acceptor molecule in Langmuir−Blodgett (LB) multilayers. Fluorescence experiments were carried out at several excitation wavelengths (220, 260, 312, and 341 nm). D1 formed a closed LB layer with a collapse area of 73 A2 on an aqueous subphase, and a successful incorporation of D1 in LB multilayers onto quartz plates was possible. At 220 nm excitation wavelength the adjacent donor and acceptor layers showed a dramatically increased fluorescence activity of the pyrene group in 213, which is about 20 times higher than that of the acceptor layer 213 without the present donor layer D1. 213 quenches the fluorescence activity of D1 more than 90% although only 5% of the maleic acid groups in 213 are labeled with pyrene. The excitation energy transfer between D1 and 213 may be assumed as a Forster energy transfer which was examined versus dista...