Spectroscopic scale protection factor (SSPF) of solar ultraviolet radiation molecular screens.: I. Salicylidene compounds

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 1998-12, Vol.119 (2), p.143-146
• Main Authors: Morales, Raúl G.E., Jara, Gregorio P., Vargas, Vı́ctor
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Molecular screens; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Salicylidenes; Solar actinic flux; Spectral bands; Sun protection factor (SPF)
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/S1010-6030(98)00396-7

We have found a new absolute scale of solar ultraviolet radiation protection factor for molecular screens, called spectroscopic scale protection factor (SSPF). This scale, based on the solar-action spectra of these molecular screens, is obtained under a 20° zenith angle of the sun actinic flux spectra at the earth's surface. In order to compare this scale versus the usual sun protection factor (SPF) scale which uses homosalate (SPF = 4.2) as a standard compound, we have determined the electronic absorption spectral properties of a salicylidene compound series. Since these aromatic compounds present a good photostability behavior, a broad absorption band and a high molar absorption coefficient in the UV-A and UV-B regions, we have established their potential use as a solar ultraviolet radiation molecular screen according to the SSPF data.