Determination of Kamlet-Taft solvent parameters π* of high pressure and supercritical water by the UV-Vis absorption spectral shift of 4-nitroanisole

Kimitaka Minami, Masamichi Mizuta, Muneyuki Suzuki, Takafumi Aizawa, Kunio Arai

    Research output: Contribution to journalArticlepeer-review

    16 Citations (Scopus)

    Abstract

    Kamlet-Taft solvent parameters, π*, of high pressure and supercritical water were determined from 16-420 °C based on solvatochromic measurements of 4-nitroanisole. For the measurements, an optical cell that could be used at high temperatures and pressures was developed with the specification of minimal dead space. The low dead space cell allowed us to measure the absorption spectra of 4-nitroanisole at high temperature conditions before appreciable decomposition occurred. The behavior of π* in terms of water density (π* = 1.77ρ- 0.71) was found to be linear, except in the near critical region, in which deviations were observed that could be attributed to local density augmentation. Excess density, which was defined as the difference between local density and bulk density, showed a maximum near the critical density of water. The frequencies of UV-Vis spectra of 4-(dimethylamino)benzonitrile and N, N-dimethyl-4-nitroaniline were correlated with π* based on a linear solvation energy relationship (LSER) theory. Local density augmentation around 4-nitroanisole and that around 4-(dimethylamino)benzonitrile were similar but the augmentation observed around N, N-dimethyl-4-nitroaniline was larger.

    Original languageEnglish
    Pages (from-to)2257-2264
    Number of pages8
    JournalPhysical Chemistry Chemical Physics
    Volume8
    Issue number19
    DOIs
    Publication statusPublished - 2006 May 11

    ASJC Scopus subject areas

    • Physics and Astronomy(all)
    • Physical and Theoretical Chemistry

    Fingerprint Dive into the research topics of 'Determination of Kamlet-Taft solvent parameters π* of high pressure and supercritical water by the UV-Vis absorption spectral shift of 4-nitroanisole'. Together they form a unique fingerprint.

    Cite this