![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
We report on absorption and fluorescence of single crystals of the unsymmetrically substituted diacetylene TS/FBS during UV-photopolymerization and thermal polymerization. All the observed reaction intermediates have been identified as diradicals, carbenes and stable oligomers. We compare these results with the well-known diacetylene TS6. The quantum yield of the initiation step as well as the activation energy of the following dark reaction have been determined. Well-separated yellow zones are characteristic for TS/FBS crystals: An additional blue-shifted polymer absorption and a strong fluorescence are typical for these regions. We compare this phenomenon with other chromism effects found with polydiacetylenes and discuss its origin.
