Enhanced Orientation in Langmuir–Blodgett Films of Tetra-tert-butyl Phthalocyanines

We report the results of structural investigations on Langmuir (L) and Langmuir–Blodgett (LB) films of tetra-tert-butyl phthalocyanine (MTBPC) containing various transition metal ions. Techniques were developed for fabricating well-ordered L-monolayers using a flow-orientation method that dramatically enhances the molecular orientation of MTBPC in L-monolayers as compared to other techniques. The dilution procedure for developing solutions enables the formation of a well-defined single L-monolayer at the air–water interface. The tilt angles of MTBPCs in the L-monolayers are estimated by the limiting area technique. The tilting structure of LB films of MTBPCs on glass substrates as measured by X-ray diffraction (XRD) method is in good agreement with the estimate obtained by the limiting area technique on the corresponding L-monolayers. An annealing procedure significantly improves the ordering of the LB films as measured by XRD.