Syntheses, characterization and properties of soluble and liquid phenanthralocyanines

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Phenanthralocyanine compounds with cumylphenoxy, nonylphenoxy and oligodimethylsiloxane phenoxy peripheral substitution were synthesized by nucleophilic aromatic substitution reaction between 3,6-difluoro-9,10-dicyanophenanthrene and the corresponding phenolic precursor. Structural characterization includes IR, NMR, UV-vis and mass spectroscopies. The nonylphenoxy and oligodimethylsiloxane phenoxy phenanthralocyanines were soluble in common organic solvents, and the siloxane product was an isotropic liquid. Compared with the phthalocyanine analog, the Q bands of the Pb , H 2 and Cu phenanthralocyanine were slightly red shifted and variably broadened (small for the Pb compound but large for the H 2 and Cu compounds). The nominal red shift is a consequence of an angular annelation of the benzene rings to the phthalocyanine system. Aggregation was not detected in toluene solution, and the Q band broadening was attributed to a distortion of the tetraazaporphyrin ring to a nonplanar conformation. The siloxane substituted lead phenanthralocyanine neat liquid was evaluated as an optical limiter material. As a neat film a substantial broadening and weakening of the Q band results in a broad visible transmission window and a relatively neutral light olive hue. Upon excitation, there is a rapid decay of the initially excited state so the initial optical limiting is predominately due to a thermorefractive effect rather than a nonlinear absorption.