Detail of "13558-31-1"

Reference

Triplet-triplet absorption spectra and the spectra of the photoreduced states of Rhodamine B and Rhodamine 110

Triplet-triplet absorption spectra and the spectra of the photoreduced states of Rhodamine B and Rhodamine 110. Dunne, A.; Quinn, M. F. (Dep. Phys., Coll. Technol., Dublin, Ire.). J. Chem. Soc., Faraday Trans. 1, 73(7), 1104-10 (English) 1977. CODEN: JCFTAR. DOCUMENT TYPE: Journal CA Section: 40 (Dyes, Fluorescent Whitening Agents, and Photosensitizers) Section cross-reference(s): 73 UV absorption spectra and extinction coeffs. for triplet-triplet absorption in alc. solns. of Rhodamine B [81-88-9] and Rhodamine 110 [13558-31-1] are presented with the quantum yields for prodn. of the triplet states in soln. and the 1st- and 2nd-order rate consts. for triplet decay in deaerated solns. Absorption spectra for the semireduced forms of the dyes are also reported.

Photoreduction of Rhodamine dyes in ethanol

I. Optical and EPR spectra of primary reduced forms. Ryl'kov, V. V.; Krymskii, Sh. Z. (USSR). Khim. Vys. Energ., 12(3), 237-41 (Russian) 1978. CODEN: KHVKAO. ISSN: 0023-1193. DOCUMENT TYPE: Journal CA Section: 40 (Dyes, Fluorescent Whitening Agents, and Photosensitizers) Section cross-reference(s): 22 Irradn. of dil. solns. (10-3-10-5M) of Rhodamine 6Zh (I) [7325-85-1], Rhodamine S [12627-64-4], or Rhodamine 110 [13558-31-1] in degassed 95% EtOH at 30° with light of wavelength corresponding to the absorption max. (546 nm for I) caused accumulation of unstable photoredn. products with lmax 412, 420, or 393 nm, resp., each of which gave a weak singlet EPR signal of line width ~8 G. The presence of electron acceptors (10-2-10-3M) had no effect on the rate of formation of these photochem. products but decreased their steady-state concn. under illumination, whereas the presence of electron donors at similar concn. levels led to an increased formation rate and steady-state concn., the greatest effect (~3 orders of magnitude) occurring with triphenylamine [603-34-9]. The disappearance of the photoredn. products when irradn. was terminated (regeneration of the initial dye) was a bimol. reaction. Reversion to the initial dye also occurred upon irradn. near the absorption max. of the reduced form (405 nm for I) or (partially) upon admission of O to the system. The initial photoredn. products were assumed to result from addn. of an electron to the dye mol. Slow irreversible consumption of the Rhodamines was attributed to interaction of the photoionized electron with the EtOH, forming hot H atoms and peroxides, which react with the dye.