Dicyanovinyl-julolidine

Fig. 4 Ground-state and excited-state energies of the TICT complexes thioflavin T (a) and 9-(dicyanovinyl)-julolidine (DCVJ) (b) as a function of the intramolecular rotation angle (data from Stsiapura et al. [13] and Allen et al. [14]). In both cases, energy levels were determined by quantum mechanical simulations. For thioflavin T, the energy difference between Si and S0 corresponds to approximately 400 nm in the planar state and 470 nm in the twisted state. In the case of DCVJ, the energy differences correspond to 310 and 960 nm, respectively. The DCVJ energy levels reflect a rotation around the vinyl double bond...

Fig. 6.7. Viscosity sensitive fluorophores molecular rotors. DCVJ = 9-(dicyanovinyl)-julolidine, CCVJ = 9-(carboxy-2-cyano)vinyl julolidine, CMAM = 2-cyano-3-(p-dimethyl-aminophenyl)acrylic acid, methyl ester.

Dispersion polymerizations of methyl methacrylate ntUizing poly(l,l,-dihydroper-fluorooctyl acrylate) as a steric stabilizer in snpercritical CO2 were carried out in the presence of helium. Particle size and particle size distribution were found to be dependent on the amonnt of inert helium present. Particle sizes ranging from 1.64 to 2.66 pm were obtained with varions amounts of helium. Solvatochromic investigations using 9-(a-perflnoroheptyl-p,p-dicyanovinyl)julolidine indicated that the solvent strength of CO2 decreases with increasing helium concentration. This effect was confirmed by calcnlations of Hildebrand solubility parameters (Hsiao and DeSimone, 1997). 

Lemert, R. M., and J. M. DeSimone. 1991. Solvatochromic characterization of near-and supercritical ethane, propane, and dimethyl ether using 9-(a-perfluoroheptyl-/8,/S-dicyanovinyl)julolidine. J. Supercritical Fluids. 4 186. 

The use of similar molecular probes in various supercritical fluids has been reported (27-34), e.g., 9-(a-perfluoroheptyl-P,P-dicyanovinyl)julolidine dye for supercritical ethane, propane, and dimethyl ether (27) nile red dye for 1,1,1,2-tetrafluoroethane (28) 4-nitroanisole and 4-nitrophenol for ethane and fluori-nated ethanes (29) 4-aminobenzophenone for fluoroform and CO2 (30) phenol blue for CO2, CHF3, N2O, and ethane (31) and coumarin-153 dye for CO2,... 

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