Study on mixed LB films of triple-decker sandwich rare earth phthalocyaninato complex

Monolayers and Langmuir-Blodgett(LB) films of the sandwich-type complex [PcDyPc(OC8H17)(8)DyPc(OC8H17)(8)] and its mixture with stearic acid (SA) have been studied. Surface pressure-area isotherm indicates that a stable monolayer was formed. The monolayer morphology was investigated by transmission electron microscopy (TEM). The aggregates of the (Pc)Dy[Pc(OC8H17)(8)]Dy[Pc(OC8H17)(8)] molecules was dispersed effectively by SA molecules as observed from TEM. Columnar domains were well ordered with the width of ca 40 nm and the length of several hundreds of nanometers as seen in the micrograph. The monolayer of the complex mixed with SA was successfully deposited on hydrophobic substrates by Langmuir-Blodgett method. The UV-Vis absorption peaks of LB film were red shifted compared with those in solution, indicating the formation of J-aggregates. The orientation angle of the phthalocyanine ring with respect to the substrate was evaluated to be ca 52degrees according to the Polarized UV-Vis spectra. The low-angle X-ray diffraction pattern showed a periodic distance of 2.41 nm for the mixed LB film. Based on all these considerations, a schematic arrangement of the complex molecules in LB films was suggested.