Molecular Orientation and Photoelectric Properties of Alloxazine Monolayer Assemblies

Langmuir‐Blodgett (LB) films of an alloxazine derivative with two dodecyl chains at 1,3‐positions showed UV/vis dichroism at normal incidence. Spectral shifts indicating aggregation of chromophores were also observed. Angular dependences of polarized absorption spectra indicated that alloxazine rings were biaxially oriented with respect to the film plane and to the dipping direction. The molecular orientation of alloxazine rings in the film plane was suggested to be induced during the transferring process of monolayers. Alloxazine LB films showed photoelectric responses corresponding to the absorption spectra. The in‐plane photoconductivity was almost isotropic and was greater than that of the through‐plane one by about five orders of magnitude.