Photophysical properties and estimation of ground and excited state dipole moments of 7-diethylamino and 7-diethylamino-4-methyl coumarin dyes from absorption and emission spectra

Abstract

Photophysical properties and estimation of ground and excited state dipole moments of 7-diethylamino and 7-diethylamino-4-methyl coumarin dyes from absorption and emission spectra

MitoBlue: A Nontoxic and Photostable Blue-Emitting Dye That Selectively Labels Functional Mitochondria

“…Application of the Lippert–Mataga model allowed us to calculate the difference between the dipole moments in the ground and the excited states as a measure of the sensitivity to the polarity. 25 − 28 The resulting value of Δμ = 7.8 D is of the same order as those measured for most environment-sensitive fluorophores, such as NBD (Δμ = 3.6) 29 or 6-DMN (Δμ = 5.5), 30 and accounts for the significant sensitivity to the solvent polarity. Furthermore, as expected for this type of cationic bisamidines, 15 , 31 compound 1 behaved in vitro as a DNA minor groove binder, exhibiting good affinity for extended A/T-rich sites ( Supporting Information ).…”

“…As expected for a push–pull conjugated system, this fluorophore is environment-sensitive, displaying a relatively weak emission in aqueous media (Φ­[H 2 O] = 0.49), but increasing its quantum yield in more hydrophobic solvents (Φ­[iPrOH] = 0.78; Φ­[EtOH] = 0.67) and particularly in nonprotic media (Φ­[dioxane] = 0.94; Φ­[THF] = 0.92). Application of the Lippert–Mataga model allowed us to calculate the difference between the dipole moments in the ground and the excited states as a measure of the sensitivity to the polarity. − The resulting value of Δμ = 7.8 D is of the same order as those measured for most environment-sensitive fluorophores, such as NBD (Δμ = 3.6) or 6-DMN (Δμ = 5.5), and accounts for the significant sensitivity to the solvent polarity. Furthermore, as expected for this type of cationic bisamidines, , compound 1 behaved in vitro as a DNA minor groove binder, exhibiting good affinity for extended A/T-rich sites (Supporting Information).…”

The Influence of Push–Pull States on the Ultrafast Intersystem Crossing in Nitroaromatics

“…We attempted an estimation of the dipole moments of the ground and fluorescent states through the method of Kawski, where the Stokes shifts (ν abs – ν fluor ) and the sum of the absorption and emission band positions (ν abs + ν fluor ) are plotted against the solvent polarity functions f (ε, n ) and f (ε, n ) + 2 g (ε, n ), respectively, as shown in Figures S17 (Supporting Information) and (see details of the method in the Supporting Information). − This analysis produced reasonable correlations for the SWB giving dipole moments of 6.9 D for the ground state and 12.1 D for the fluorescent state associated to this transition (SWB). On the contrary, the Kawski method does not produce a reasonable systematic trend for the LWB (see inset of Figure S17, Supporting Information), so that the Kawski analysis could not be performed for this state.…”

Photophysical Properties of Coumarin 1 in Bile Salt Aggregates: An Insight into the Role of Bile Salt Structure on the Aggregation Behavior

“…Fluorescence behavior of Cou1 is known to be very sensitive to the solvent properties. − Hence, to evaluate the influence of different bile salts on Cou1 photophysics, steady-state fluorescence spectra of Cou1 with increasing concentrations of bile salts were recorded. Cou1 exhibits weak fluorescence in pure aqueous medium with a broad and structureless emission around 470 nm.…”