SOLVATOCHROMIC FLUORESCENT-PROBES FOR MONITORING THE PHOTOPOLYMERIZATION OF DIMETHACRYLATES

The fluorescent probes 7-(dimethylamino)-4-(trifluoromethyl)coumarin (1), N,N-di-n-butyl-5-(dimethylamino)-1-naphthalenesulfonamide (2), 4-(dimethylamino)-4'-(methylsulfonyl)st (3), 4-(dimethylamino)-4'-(methylsulfonyl)diphenyl (4), and 4-(dimethylamino)-4'-nitrostilbene (5) (Figure 2) were incorporated in polymeric networks formed by photopolymerization of dimethacrylates of different molecular sizes and polarities (Figure 3). The response of the probe's emission to changes in its environment during photopolymerization was determined and compared with the emissions in solvents of low viscosity of differing polarities (solvatochromism). A comparison between these data reveals that the blue shifts observed during polymerization are roughly proportional to the solvatochromism of each probe.