  Here we report the design and synthesis of an imidazole derivative namely
1-benzyl-2,4,5-triaryl imidazole and its switching behaviour assembled onto
Langmuir-Blodgett films. Monolayer characteristic of imidazole at the air-water
interface has been studied by surface pressure vs area per molecule isotherm,
hysteresis analysis and insitu Brewster Angle Microscopy . These studies
indicated the formation of stable floating Langmuir film at the water subphase.
Atomic Force Microscopy investigation confirmed the successful deposition of
the Langmuir film onto solid substrate. Device consisted of 60 layers LB films
of imidazole showed resistive bipolar switching behaviour irrespective of the
first applied bias voltage polarity. Observed bipolar switching has been
explained in terms of reduction oxidation process. Due to the presence of
strong reducible group C double bond N in the imidazole core, reduction
oxidation process takes place easily during bias. Presence of sharp reduction
and oxidation peaks in the Cyclic Voltammetry measurement of 2 also supported
this hypothesis. Presence of benzyl group with the imidazole core played the
crucial rule in the reduction oxidation process and hence the switching
behaviour. When benzyl group was replaced by a H then bipolar switching was not
observed. In that case oxidizable group NH opposed the reduction process during
bias. This type of bipolar switching is very promising for future technological
applications in organic electronics.
