Spectroscopic investigation of cyanovinyl-diethylaniline dyes in solutions

Saturable absorption dynamics of a cyanovinyl-diethylaniline dye

“…The low fluorescence quantum efficiencies may be due to fast internal conversion caused by the rotational movement of flexible molecular groups [10,11,13,16,17,24]. In this case, the fluorescence signal is emitted from the vibrational^ relaxed excited S!…”

“…The fluorescence quantum efficiencies q in the vapor phase [15] and in liquid solutions [9][10][11][12]16] were found to be very small (q< 10 ~3). Temperature-dependent fluorescence-quantum-efficiency measurements indicated an intrinsic barrierless deactivation [16].…”

“…The fluorescence quantum efficiencies q in the vapor phase [15] and in liquid solutions [9][10][11][12]16] were found to be very small (q< 10 ~3). Temperature-dependent fluorescence-quantum-efficiency measurements indicated an intrinsic barrierless deactivation [16]. Since the viscous drag of the dye surroundings determines the fluorescence lifetime of these dyes [9][10][11][12][13][17][18][19][20][21], they are applied as micro-viscosity probes and free-volume probes in micellar emulsions [9] and polymers [10][11][12][13][17][18][19][20][21].…”

“…The absorption and emission spectroscopic properties of 4-dicyanovinyl-N,N-diethylaniline (DCVA) [9][10][11][12][13][14][15][16] and 4-tricyanovinyl-N,N-diethylaniline (TCVA) [15,16] have been investigated recently. The fluorescence quantum efficiencies q in the vapor phase [15] and in liquid solutions [9][10][11][12]16] were found to be very small (q< 10 ~3).…”

“…Since the viscous drag of the dye surroundings determines the fluorescence lifetime of these dyes [9][10][11][12][13][17][18][19][20][21], they are applied as micro-viscosity probes and free-volume probes in micellar emulsions [9] and polymers [10][11][12][13][17][18][19][20][21]. The analysis of the solvent-dependent spectral absorption and emission shifts revealed a partial intramolecular charge transfer in the excited Si state [9,10,13,16,18,22,23].…”