Enhanced orientation in Langmuir-Blodgett films of tetra-tert-butyl phthalocyanines

We report the results of structural investigations on Langmuir (L) and Lang muir-Blodgett (LB) films of tetra-tert-butyl phthalocyanine (MTBPC) contain ing various transition metal ions. Techniques were developed for fabricatin g well-ordered L-monolayers using a how-orientation method that dramaticall y enhances the molecular orientation of MTBPC in L-monolayers as compared t o other techniques. The dilution procedure for developing solutions enables the formation of a well-defined single L-monolayer at the air-water interf ace. The tilt angles of MTBPCs in the L-monolayers are estimated by the lim iting area technique. The tilting structure of LB films of MTBPCs on glass substrates as measured by X-ray diffraction (XRD) method is in good agreeme nt with the estimate obtained by the limiting area technique on the corresp onding L-monolayers. An annealing procedure significantly improves the orde ring of the LB films as measured by XRD.