Specific solute-solute and solute-solvent interactions in organic solutions of indole

Singlet and triplet quenching of indole by heavy atom containing molecules in a low temperature glassy matrix. Evidence for complexation in the triplet state

“…The spectrum of indole in the ethanol-ether mixture is typical of those indole spectra published in polar low temperature matrices. 22,23 In din-propyl ether at -184 °C it was suggested that an indole-ether complex exists and is responsible for the decrease in the xLa band intensity compared to that of the band, when the temperature is lowered. The same behavior was observed in ethanol.22"23 The 0-0 ^band intensity at 287 nm is not affected by the external heavy atom perturbers which do not absorb at this wavelength in the concentration range used here.…”

Questioning the photophysical model for the indole chromophore in the light of evidence obtained by controlling the non-specific effect of the medium with 1-chlorobutane as solvent

“…In 1970, Strickland et al 50 compared the first absorption band of indole in the gas phase, as well as in perfluorinated hexane and methylcyclohexane solutions, and found that switching from the gas phase to the condensed phase resulted in a red shift in the series of peaks in the first absorption band for gaseous indole in the 260 nm region; they assigned such peaks to the 1 L a state of indole and all others to its 1 L b state. In research conducted in the same direction, Cazeau-Dubroca et al 51 compared the behaviour of the first absorption band of indole in 3-methylpentane (3MP) and di-n-propyl ether (PE), and found a wide zone in the first absorption band falling at a shorter (bluer) wavelength than that at ca. 260 nm to undergo a red shift in going from 3MP to PE.…”

Two‐colour two‐photon confocal microscopy with isotropic three‐dimensional resolution and parallel excitation

“…The two excitation wavelengths are related in the following manner: 1/λ e = 1/λ 1 + 1/λ 2 , where λ e is the single‐photon excitation wavelength of the sample. In the simulation of our paper, we consider the case λ 1 = 400 nm, λ 2 = 800 nm, λ e = 267 nm and assume indole as the sample that has a one‐photon excitation peak of 260 nm (Caseau‐Dubroca et al , 1973) and fluorescence emission maximum at 337 nm (Gryczynski et al , 1997). Other parameters for our numerical experiment are as follows: the collecting lens (L6) is oil‐immersion with a numerical aperture of 1.3 and a refractive index of 1.518; and sample is idealized with a uniform refractive index of 1.518.…”