KINETIC-ANALYSIS OF THE PHOTOCHROMIC BEHAVIOR OF A NATURALLY-OCCURRING CHROMENE (LAPACHENOLE) UNDER STEADY IRRADIATION

Authors
FAVARO G MAZZUCATO U OTTAVI G BECKER R
Citation
G. Favaro et al., KINETIC-ANALYSIS OF THE PHOTOCHROMIC BEHAVIOR OF A NATURALLY-OCCURRING CHROMENE (LAPACHENOLE) UNDER STEADY IRRADIATION, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 297, 1997, pp. 413-420
Citations number
9
Categorie Soggetti
Crystallography
Journal title
Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals → ACNP
ISSN journal
1058725X
Volume
297
Year of publication
1997
Pages
413 - 420
Database
ISI
SICI code
1058-725X(1997)297:<413:KOTPBO>2.0.ZU;2-N
Abstract
The photokinetic behavior of a naturally occurring chromene, lapacheno le (2,2-dimethyl-6-methoxy-7,8-benzo(2H)chromene, Ch), has been invest igated by using monochromatic irradiation in the UV and visible ranges . Two colored photoproducts were identified: one is thermoreversible, the other is thermostable and photoreversible. The quantum yields of t he color-forming and color-bleaching photoreactions were determined by a spectrokinetic method. The kinetic parameters of the thermal steps were measured (285 - 325 K). The sensitized color-forming reaction was also investigated, using thioxantone as a triplet sensitizer. A plaus ible reaction mechanism is proposed.