Fabrication of Langmuir-Blodgett films of metallo- phthalocyanines by flow-orientation and dilution methods

Abstract

This paper reports on novel fabrication techniques for well-ordered Langmuir (L) and Langmuir-Blodgett (LB) films of metallo tetra-tert-butyl phthalocyanines (MTBPcs) containing various transition metal ions, i.e. Co 2+, Cu 2+, Zn 2+ and VO 2+. An extreme dilute concentration of a developing solution releases the aggregation state of MTBPcs. Furthermore, the flow-orientation adjusts in-plane ordering of MTBPcs. Both procedures enable the fabrication of well-ordered L-monolayers of MTBPcs at the air-water interface. For the LB films prepared by the vertical dipping method, an annealing procedure dramatically improves the ordering of MTBPcs. Electron paramagnetic resonance spectroscopy also reveals that a spin-chain system in the MTBPc LB films possesses a two-dimensional order.