ONE-DIMENSIONAL COLUMNAR STRUCTURE IN CONDUCTIVE LANGMUIR-BLODGETT-FILMS OF LONG-CHAIN PYRIDINIUM-(TCNQ)2 SALTS STUDIED BY ELECTRON-SPIN-RESONANCE

Langmuir-Blodgett (LB) films of a long-chain pyridinium-(TCNQ)2 salt ( where TCNQ denotes tetracyanoquinodimethane), APT(8-12), exhibit a pho toinduced conductivity change associated with the trans cis isomerizat ion of the azobenzene group in the molecule. Recently the development of a one-dimensional (1D) columnar structure in the LB films of a simi lar long-chain pyridinium-(TCNQ)2 salt, C22PT, was indicated through q uantitative analyses of the temperature-dependent spin susceptibility and the angular-dependent electron spin resonance line shape. The appl ication of these methods to the APT(8-12) films has provided another e xample of a quasi-1D spin system realized in the LB film system.