Photoexcited states of UV absorbers, benzophenone derivatives

Ryo Kumasaka, Azusa Kikuchi, Mikio Yagi

    • 10 Citations

    Abstract

    The UV absorption, phosphorescence and phosphorescence-excitation spectra of benzophenone (BP) derivatives used as organic UV absorbers have been observed in rigid solutions at 77 K. The triplet-triplet absorption spectra have been observed in acetonitrile at room temperature. The BP derivatives studied are 2,2,4,4-tetrahydroxybenzophenone (BP-2), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,2-dihydroxy-4,4-dimethoxybenzophenone (BP-6), 5-chloro-2-hydroxybenzophenone (BP-7) and 2-hydroxy-4-n-octyloxybenzophenone (BP-12). The energy levels and lifetimes of the lowest excited triplet (T1) states of these BP derivatives were determined from the first peak of phosphorescence. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. The possible mechanism of the observed phosphorescence enhancement is discussed. The T1 states of 2-hydroxy-5- methylbenzophenone, 4-methoxybenzophenone and 2,4-dimethoxybenzophenone have been studied for comparison. The energy levels and lifetimes of the lowest excited triplet states of benzophenone (BP) derivatives, BP-2, BP-3, BP-6, BP-7 and BP-12, used as organic UV absorbers in cosmetic sunscreens were determined in rigid solutions at 77 K. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. © 2014 The American Society of Photobiology.

    Original languageEnglish
    Pages (from-to)727-733
    Number of pages7
    JournalPhotochemistry and Photobiology
    Volume90
    Issue number4
    DOIs
    StatePublished - 2014 Jan 1

    Fingerprint

    Temperature
    Photosensitivity Disorders
    Singlet Oxygen
    Ethanol
    Sunscreening Agents
    Cosmetics

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Biochemistry
    • Medicine(all)

    Cite this

    Photoexcited states of UV absorbers, benzophenone derivatives. / Kumasaka, Ryo; Kikuchi, Azusa; Yagi, Mikio.

    In: Photochemistry and Photobiology, Vol. 90, No. 4, 01.01.2014, p. 727-733.

    Research output: Contribution to journalArticle

    Kumasaka, Ryo; Kikuchi, Azusa; Yagi, Mikio / Photoexcited states of UV absorbers, benzophenone derivatives.

    In: Photochemistry and Photobiology, Vol. 90, No. 4, 01.01.2014, p. 727-733.

    Research output: Contribution to journalArticle

    @article{e4e2a928ea2346508948d1fb2f45aa72,
    title = "Photoexcited states of UV absorbers, benzophenone derivatives",
    author = "Ryo Kumasaka and Azusa Kikuchi and Mikio Yagi",
    year = "2014",
    month = "1",
    doi = "10.1111/php.12257",
    volume = "90",
    pages = "727--733",
    journal = "Photochemistry and Photobiology",
    issn = "0031-8655",
    publisher = "Wiley-Blackwell",
    number = "4",

    }

    TY - JOUR

    T1 - Photoexcited states of UV absorbers, benzophenone derivatives

    AU - Kumasaka,Ryo

    AU - Kikuchi,Azusa

    AU - Yagi,Mikio

    PY - 2014/1/1

    Y1 - 2014/1/1

    N2 - The UV absorption, phosphorescence and phosphorescence-excitation spectra of benzophenone (BP) derivatives used as organic UV absorbers have been observed in rigid solutions at 77 K. The triplet-triplet absorption spectra have been observed in acetonitrile at room temperature. The BP derivatives studied are 2,2,4,4-tetrahydroxybenzophenone (BP-2), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,2-dihydroxy-4,4-dimethoxybenzophenone (BP-6), 5-chloro-2-hydroxybenzophenone (BP-7) and 2-hydroxy-4-n-octyloxybenzophenone (BP-12). The energy levels and lifetimes of the lowest excited triplet (T1) states of these BP derivatives were determined from the first peak of phosphorescence. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. The possible mechanism of the observed phosphorescence enhancement is discussed. The T1 states of 2-hydroxy-5- methylbenzophenone, 4-methoxybenzophenone and 2,4-dimethoxybenzophenone have been studied for comparison. The energy levels and lifetimes of the lowest excited triplet states of benzophenone (BP) derivatives, BP-2, BP-3, BP-6, BP-7 and BP-12, used as organic UV absorbers in cosmetic sunscreens were determined in rigid solutions at 77 K. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. © 2014 The American Society of Photobiology.

    AB - The UV absorption, phosphorescence and phosphorescence-excitation spectra of benzophenone (BP) derivatives used as organic UV absorbers have been observed in rigid solutions at 77 K. The triplet-triplet absorption spectra have been observed in acetonitrile at room temperature. The BP derivatives studied are 2,2,4,4-tetrahydroxybenzophenone (BP-2), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,2-dihydroxy-4,4-dimethoxybenzophenone (BP-6), 5-chloro-2-hydroxybenzophenone (BP-7) and 2-hydroxy-4-n-octyloxybenzophenone (BP-12). The energy levels and lifetimes of the lowest excited triplet (T1) states of these BP derivatives were determined from the first peak of phosphorescence. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. The possible mechanism of the observed phosphorescence enhancement is discussed. The T1 states of 2-hydroxy-5- methylbenzophenone, 4-methoxybenzophenone and 2,4-dimethoxybenzophenone have been studied for comparison. The energy levels and lifetimes of the lowest excited triplet states of benzophenone (BP) derivatives, BP-2, BP-3, BP-6, BP-7 and BP-12, used as organic UV absorbers in cosmetic sunscreens were determined in rigid solutions at 77 K. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K. © 2014 The American Society of Photobiology.

    UR - http://www.scopus.com/inward/record.url?scp=84903819545&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84903819545&partnerID=8YFLogxK

    U2 - 10.1111/php.12257

    DO - 10.1111/php.12257

    M3 - Article

    VL - 90

    SP - 727

    EP - 733

    JO - Photochemistry and Photobiology

    T2 - Photochemistry and Photobiology

    JF - Photochemistry and Photobiology

    SN - 0031-8655

    IS - 4

    ER -