The anisotropic gas response behavior of LB films of an amphiphilic asymmetrically substituted phthalocyanine

1,4-Di(2-hydroxyethoxy)-9,10,16,17,23,24-hexapentyloxy phthalocyanine (asy- Pc) has been deposited as well-ordered Langmuir-Blodgett (LB) films on a gl ass substrate and glass-bearing interdigital electrodes. The molecular orie ntation of the asy-Pc LB films has been characterized by polarized UV-vis a bsorption spectra and in-plane dichroism has been observed. The LB films sh ow good room temperature response to NO2 gas and the recovery is almost com plete. It has been found that the magnitude of the response increases with increasing gas concentration and is also dependent upon the LB dipping dire ction relative to the arms of the electrodes, consistent with conduction be ing favored along the axes of the stacks of asy-Pc molecules. (C) 1999 Else vier Science S.A. All rights reserved.