Molecular and vibrational structure of 2,2'-dihydroxybenzophenone

Infrared linear dichroism spectroscopy and quantum chemical calculations

Kristine Birklund Andersen, M. Langgård, Jens Spanget-Larsen

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskning

    Resumé

    2,2'-dihydroxybenzophenone (DHBP) contains similar bifold intramolecular H-bonding as the psoriatic drug anthralin, but because of steric interference the phenolic rings are twisted in a propeller-like manner, resulting in a molecular structure of C2 symmetry. In contrast to the case of C2v anthralin, the description of the vibrational structure of the compound is thus complicated by the circumstance that moment directions for transitions polarized perpendicular to the C2 axis (z) are not uniquely determined by symmetry, but can take any direction in the xy plane. The molecular vibrations of DHBP were investigated by IR polarization spectroscopy on samples aligned in stretched polyethylene. The observed Linear Dichroic (LD) absorbance curves, corresponding to absorbance measured with the electric vector of the sample beam parallel (U) and perpendicular (V) to the stretching direction, were analyzed by the stepwise reduction procedure, and in spite of relatively poor alignment, approximate orientation factors K could be determined for 27 vibrational transitions. On the basis of the polarization data and with the help of theoretical predictions it was possible to assign the most important fundamentals observed in the IR spectra. Theoretical predictions at the HF/6-31G* level did not lead to satisfactory agreement with the observed transitions, but the results obtained with B3LYP/6-31G* was in excellent consistency with the general appearance of the observed spectra.
    OriginalsprogEngelsk
    TidsskriftPolarization Spectroscopy of Ordered Systems - PSOS
    StatusUdgivet - 1999

    Citer dette

    @article{adb0620052ce11db8236000ea68e967b,
    title = "Molecular and vibrational structure of 2,2'-dihydroxybenzophenone: Infrared linear dichroism spectroscopy and quantum chemical calculations",
    abstract = "2,2'-dihydroxybenzophenone (DHBP) contains similar bifold intramolecular H-bonding as the psoriatic drug anthralin, but because of steric interference the phenolic rings are twisted in a propeller-like manner, resulting in a molecular structure of C2 symmetry. In contrast to the case of C2v anthralin, the description of the vibrational structure of the compound is thus complicated by the circumstance that moment directions for transitions polarized perpendicular to the C2 axis (z) are not uniquely determined by symmetry, but can take any direction in the xy plane. The molecular vibrations of DHBP were investigated by IR polarization spectroscopy on samples aligned in stretched polyethylene. The observed Linear Dichroic (LD) absorbance curves, corresponding to absorbance measured with the electric vector of the sample beam parallel (U) and perpendicular (V) to the stretching direction, were analyzed by the stepwise reduction procedure, and in spite of relatively poor alignment, approximate orientation factors K could be determined for 27 vibrational transitions. On the basis of the polarization data and with the help of theoretical predictions it was possible to assign the most important fundamentals observed in the IR spectra. Theoretical predictions at the HF/6-31G* level did not lead to satisfactory agreement with the observed transitions, but the results obtained with B3LYP/6-31G* was in excellent consistency with the general appearance of the observed spectra.",
    author = "{Birklund Andersen}, Kristine and M. Langg{\aa}rd and Jens Spanget-Larsen",
    year = "1999",
    language = "English",
    journal = "Polarization Spectroscopy of Ordered Systems - PSOS",
    publisher = "Roskilde University, Department of Science, Systems and Models & Roskilde University Library",

    }

    TY - JOUR

    T1 - Molecular and vibrational structure of 2,2'-dihydroxybenzophenone

    T2 - Infrared linear dichroism spectroscopy and quantum chemical calculations

    AU - Birklund Andersen, Kristine

    AU - Langgård, M.

    AU - Spanget-Larsen, Jens

    PY - 1999

    Y1 - 1999

    N2 - 2,2'-dihydroxybenzophenone (DHBP) contains similar bifold intramolecular H-bonding as the psoriatic drug anthralin, but because of steric interference the phenolic rings are twisted in a propeller-like manner, resulting in a molecular structure of C2 symmetry. In contrast to the case of C2v anthralin, the description of the vibrational structure of the compound is thus complicated by the circumstance that moment directions for transitions polarized perpendicular to the C2 axis (z) are not uniquely determined by symmetry, but can take any direction in the xy plane. The molecular vibrations of DHBP were investigated by IR polarization spectroscopy on samples aligned in stretched polyethylene. The observed Linear Dichroic (LD) absorbance curves, corresponding to absorbance measured with the electric vector of the sample beam parallel (U) and perpendicular (V) to the stretching direction, were analyzed by the stepwise reduction procedure, and in spite of relatively poor alignment, approximate orientation factors K could be determined for 27 vibrational transitions. On the basis of the polarization data and with the help of theoretical predictions it was possible to assign the most important fundamentals observed in the IR spectra. Theoretical predictions at the HF/6-31G* level did not lead to satisfactory agreement with the observed transitions, but the results obtained with B3LYP/6-31G* was in excellent consistency with the general appearance of the observed spectra.

    AB - 2,2'-dihydroxybenzophenone (DHBP) contains similar bifold intramolecular H-bonding as the psoriatic drug anthralin, but because of steric interference the phenolic rings are twisted in a propeller-like manner, resulting in a molecular structure of C2 symmetry. In contrast to the case of C2v anthralin, the description of the vibrational structure of the compound is thus complicated by the circumstance that moment directions for transitions polarized perpendicular to the C2 axis (z) are not uniquely determined by symmetry, but can take any direction in the xy plane. The molecular vibrations of DHBP were investigated by IR polarization spectroscopy on samples aligned in stretched polyethylene. The observed Linear Dichroic (LD) absorbance curves, corresponding to absorbance measured with the electric vector of the sample beam parallel (U) and perpendicular (V) to the stretching direction, were analyzed by the stepwise reduction procedure, and in spite of relatively poor alignment, approximate orientation factors K could be determined for 27 vibrational transitions. On the basis of the polarization data and with the help of theoretical predictions it was possible to assign the most important fundamentals observed in the IR spectra. Theoretical predictions at the HF/6-31G* level did not lead to satisfactory agreement with the observed transitions, but the results obtained with B3LYP/6-31G* was in excellent consistency with the general appearance of the observed spectra.

    UR - http://rudy.ruc.dk/psos/99/990302.htm

    M3 - Journal article

    JO - Polarization Spectroscopy of Ordered Systems - PSOS

    JF - Polarization Spectroscopy of Ordered Systems - PSOS

    ER -