Reactions in Polymers and Other Matrices

Dendrimers with terminal ( )-stilbene moieties based either on a hexamine core or on a benzenetricarboxylic acid core were prepared under irradiation [38]. Both types of dendrimers were found to undergo photochemical reactions to yield cross-linked products lacking styryl moieties. 

Photochemical and photophysical properties of a poly(propylene amine) dendrimer (2) functionalized with -stilbene units have been studied [39]. The E Z photoisomerization and photocyclization of the Z-isomer of the stilbene units were investigated in air equilibrated acetonitrile solutions. The quantum yields of the E Z photoisomerization reaction and the fluorescence quantum yield of the E were found to be equal to 0.30 and 0.014, respectively. The stilbene moiety underwent the photocyclization to phenanthrene with quantum yield 0.015. Photochemical processes of the main-chain nematic LC polymer containing trans-4,4 -stilbene-bis-carboxylate chromophore/mesogen was studied in solvents and in spin cast thin 

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