Abstract: A process for preparing film structures comprising phthalocyanine oligomers having metal coordinating atoms in adjacent rings connected along a central axis through oxygen atoms. The ligands on the outermost rings of the structures are hydrophilic. The preferred coordinating atom is germanium and the structures may be prepared on a Langmuir-Blodgett balance using phthalocyanine oligomers in which one of the outermost rings is connected to a hydrophobic ligand while the other outermost ring is connected to a hydrophilic ligand. The pH of the subphase in the trough of the balance is maintained at a pH of from about 2 to 6, and the hydrophobic ligand is converted to a hydrophilic ligand during the process of coating a substrate by passing it upward through the film on the subphase.