On the diversity of reversible products of phototransformations in ethanol solutions of rhodamines at stepwise quantum excitation

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Optics and Spectroscopy

OSTI ID:457035

Aristov, A V; Kozlovskii, D A; Nikolaev, A B ^[1]

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1. Vavilov State Optical Inst., St. Petersburg (Russian Federation)

The formation of various reversible products of phototransformations (RPP) in rhodamine 6G (R6G), rhodamine C (RC), and unsubstituted rhodamine (UR) solutions at pulsed stepwise quantum excitation is investigated. The dependence of the type of RPP on the specific system of molecular orbitals (MO), within the bounds of which light quanta are absorbed, is revealed. The excitation of molecules in the MO system responsible for absorbing the light with the wavelength {lambda} = 353 nm leads to formation of RPP, mainly as semioxidized forms of R6G, RC, an UR with a lifetime {tau} = 10{sup {minus}10}-10{sup {minus}9} s. The excitation of molecules in another system of orbitals, namely, in the system responsible for absorbing the light with {lambda} = 532 nm, is accompanied by formation of RPP with {tau} = 10{sup {minus}7}-10{sup {minus}6} s in the form of lactone modifications of RC and UR. Under similar conditions of exciting R6G molecules, the dye is converted not to the lactone form, but to another type of RPP with the same lifetime and with a much larger activation energy for its formation. The prospects of applying RPP in rhodamine solutions for the real-time optical control of spectral properties of these solutions are evaluated. 14 refs.

• OSTI ID: 457035
• Journal Information: Optics and Spectroscopy, Journal Name: Optics and Spectroscopy Journal Issue: 3 Vol. 78; ISSN OPSUA3; ISSN 0030-400X
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
ETHANOL
EXCITATION
FLUORESCENCE
PHOTOCHEMICAL REACTIONS
RHODAMINES
SOLITONS