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Tetrakis-4-(2,4-di-tert-amylphenoxy)phthalocyaninato-polysiloxane was synthesized. Its molecular structure was confirmed by elemental analysis, IR and UV-vis spectra. The gas-sensitive properties of its Langmuir–Blodgett films exposed to NH₃, I₂ and NO₂ in air were measured. The results showed that the detection sensitivity on exposure to NH₃ in air can reach 0.1 ppm, while it can reach 100 ppm on exposure to NO₂ and I₂ in air.

Tetrapyridotetraazaporphyrinatozinc (TPyTAPZn) can be looked at as a substituted phthalocyanine. Thin films of TPyTAPZn were prepared on quartz glass by physical vapour deposition under high-vacuum conditions. During the deposition, island growth was observed by a characteristic change in the electrical conduction, indicating an increasing number of conduction pathways along the film. Deposition conditions could be optimized to yield an ordered rather than amorphous growth as detected by a characteristic absorption band in the visible range, strongly red-shifted from the absorption of the monomeric molecule in solution. A negative Seebeck coefficient confirmed n-type conduction for TPyTAPZn. In temperature-dependent measurements of the electrical conductivity and thermopower across the samples an activation energy of 0.31 eV was established for the conductivity and of 0.04 eV for charge carrier generation. From this difference it is concluded that a thermally activated charge carrier transport mechanism (hopping) rather than delocalized conduction (band model) is dominant in TPyTAPZn. Photoconduction turned out to be rather small in these samples, although light was absorbed quite efficiently. The time dependence of photoconduction indicated a significant trap density. Interaction with ammonia or triethylamine in the gas phase led to an increase in the conductivity; oxygen or water led to a decrease. The time dependence of these interactions indicated that triethylamine and water were only reacting with the surface region, whereas NH₃ and O₂ were also diffusing into the bulk of the films.

Several recent studies of phthalocyanines and porphyrins as materials in emerging technologies are reviewed here. Emphasis is placed on the use of these materials as components in building materials where the symmetry, optical and electrical properties of the molecule are important. Aggregates or polymers of these molecules have been known for some time to possess interesting electrical conductivities, and more recently interesting optical properties. Their optical properties as isolated species in condensed phases have also recently become interesting, and their ability to form new hybrid materials, by mixing or by thin film deposition, with other molecules with different electron affinities and ionization potentials, now appears to be extremely attractive. Device technologies in which we can anticipate these molecules appearing in the near future include organic light-emitting diodes, organic field effect transisitors, organic photovoltaics, optical limiters and optically based chemical sensors.