The control of molecular self-association in spin-coated films of substituted phthalocyanines

Uniform thin films are needed for the exploration and exploitation of the f ascinating optical and electronic properties of the phthalocyanine (Pc) mac rocycle. Spin-coating has been demonstrated to be a simple, fast and reprod ucible method of fabricating uniform films. However, solubility in a volati le organic solvent is a prerequisite for this technique and previous studie s have shown that groups placed on the Pc macrocycle can have a profound ef fect on the nanoscale structure of the resulting film. In this paper we att empt to establish some fundamental structure-property relationships which d etermine the molecular packing within such films. Previous studies are revi ewed and the film forming properties of a number of Pc derivatives are exam ined. In particular, the formation of films in which the Pc cores are isola ted from each other by the use of novel, sterically crowded hexadeca-substi tuted Pcs is examined.