Imaging by Sensitized Oxygenations of Photochromic Anthracene Films: Examination of Effects That Improve Performance and Reversibility

Abstract

The aliphatic anthracene compound 1 and the oligomeric anthracene 2 were synthesized. Thin films of 1 and 2 mixed with the sensitizers tetraphenylporphyrin (TPP) and methylene blue (MB) were irradiated with visible light in air. Upon formation of singlet oxygen, the anthracene units were converted quantitatively to the corresponding endoperoxides. Heating of the irradiated samples afforded the parent anthracenes with high yields. Here, we demonstrate that the kinetics and reversibility of this reaction strongly depend on the microenvironment of the anthracene groups in the two compounds. The photooxidation of thin films of 1 is accompanied by interesting changes in the morphology of the film and allows the first application of 1 as a nondestructive negative-tone photoresist for lithography and as an oxidizing ink. The morphology of 2 remained unchanged after photooxidation as a result of the stabilizing oligomer backbone. This stabilizing effect significantly improves the photochromic performance of 2. The reversibility of the photooxidation is very high (>90 %) for oligomeric films of 2 after several cycles of irradiation and heating. Decomposition of the anthracene and a loss of the activity of the sensitizer diminish slightly the performance of the monomeric species.

Reversible oxygen addition on a triplet sensitizer molecule: protection from excited state depopulation

“…Residual solid was recrystallized from ethanol to give 10-phenyl-9bromoanthracene (4.59 g, 95%) as yellow crystals with m.p. 35 A mixture of 10-phenyl-9-bromoanthracene (2.5 g, 7.5 mmol), 4-formylphenylboronic acid (1. 153-155 o C).…”

Surface energy gradient driven convection for generating nanoscale and microscale patterned polymer films using photosensitizers

“…The chemical mechanism is shown in Figure . Light exposure in the presence of ambient O 2 produces an endoperoxide form of DBA by (4π + 2π) cycloaddition with singlet oxygen . Subsequent heating yields free radicals that chemically modify the PiBMA film in a number of potential ways.…”

Mechanism for the photodegradation of 9,10-dibutoxyanthracene in the presence of air

“…Wilkinson et al investigated the mechanism of singlet oxygen production from anthracene derivatives, revealing that the change in the singlet oxygen production efficiency depended on the substituents at positions 9 and 10 [16]. Anthracene derivatives can also combine with singlet oxygen to form an EPO, which has been investigated both theoretically and experimentally [18,19].…”