Probing Based on Solvatochromism

N-Dimethylamino)stiIbene (DS), 4-(l-aza-15-Crown-5)stilbene (DS-Crown) and regioselectively bridged 4-(N,N-dialkylamino)stUbene derivatives (DS-B2, DS-B4, DS-B24, DS-B34) have been synthesized and their solvatochromism was measured [31]. In ethanol, the fluorescence quantum yields were obtained at room 

The fluorescent probes, 4-(dimethylamino)-4 -(methylsulfonyl)stilbene, 4-(dimethylamino)-4 -(methylsulfonyl)diphenylbutadiene, and 4-(dimethylarriino)-4 -nitrostUbene, were incorporated in polymeric networks formed by photopolymerization of dimethacrylates of different molecular sizes and polarities [32]. The response of the probe s emission to changes in its environment during photopolymerization was detected and compared with the emissions in solvents oflow viscosity of differing polarities. A comparison between these data revealed that the blueshifts observed during polymerization were roughly proportional to the solvatochromism of each probe. 

The sensitive solvatochromism of 2,5-dicyano-4-methyl-4 -(9-carbazolyl)stUbene (1) and 2,5-dicyano-4-methyl-4 -bis-(hydroxyethyl) aminostilbene (2) was described [33]. The emission maximum and two-photon absorption cross section (8TPA) of 1 and 2 vary from 412 and 453 nm in cyclohexane to 534and 629 nm in DMSO and from 6930 GM in cyclohexane and 2880 GM in 1,4-dioxane to 1050 and 130 GM in 

Strongly redshifted fluorescence, as the solvent polarity was increased, demonstrated the formation of an intramolecular charge transfer state. Compounds under study were used as fluorescence probes for monitoring the kinetics of thermally initiated polymerization of methyl methacrylate and photoinitiated polymerization of 2-ethyl-2-(hydroxymethyl)propane-l,3-diol triacrylate. 

---