MONOLAYER BEHAVIOR OF MONOVALENT AND DIVALENT SALTS OF LONG-CHAIN ALKYLAMMONIUM [NI(DMIT)2] AND ALKYLAMMONIUM [NI(MNT)2]

Monovalent and divalent long-chain alkylammonium salts of [Ni(dmit)2] and [Ni(mnt)2] are shown to form monolayers at the air-water interface albeit with difficulty. Reproducible pressure-area isotherms are only obtained after monolayers are left fully expanded at the air-water interface for long periods of time. Surface potential measurements and phase contrast microscopy have been used to show that the quality of LB films of these charge transfer salts are greatly improved by long spreading times on the water surface. Mixing the pure salt with a long-chain fatty acid is found to improve the spreading characteristics of the salt but the resulting mixed monolayer is likely to be composed of two separate phases.