Coordination induced monolayer formation and fabrication of a novel conductive Langmuir-Schaefer film of benzimidazole-containing Schiff bases without a substituted alkyl chain

Two benzimidazole-containing Schiff bases: 2-[(2'-hydroxybenzylidene)amino] benzimidazole (HBA) and 2-[(2'-hydroxynaphthylmethylidene)amino]benzimidazo le (HNA), which have no substituted long alkyl chain, have been found to fo rm stable monolayers at the air-water interface when Ag(I) ions are present in the subphase. The monolayers can be further transferred onto solid subs trates using the horizontal lifting method. The transferred films were char acterized by UV-Vis absorption, X-ray photoelectron spectra (XPS) and X-ray diffraction. It has been found that monolayers were formed through the coo rdination between the benzimidazole moiety and Ag(I) ions. The transferred Langmuir-Schaefer (LS) films thus formed showed a relatively large conducti vity in the order of 10(-1) S cm(-1). In addition, photoirradiation upon th e film can cause a change in the conductivity.