Contrast effect of hydrogen bonding on the acceptor and donor OH groups of intramolecularly hydrogen-bonded OH pairs in diols.
We studied the influence of hydrogen bonding on the fundamental and overtone bands of the OH-stretching vibration of each OH group in the intramolecularly hydrogen-bonded OH(I)::OH(II) pair in 1,2-, 1,3- and 1,4-diols. The hydrogen bonding between the two OH groups significantly increases in strength from the five-membered ring of a 1,2-diol to the seven-membered ring of a 1,4-diol. Although the hydrogen bonding does not affect the vibrational property of the OH(II) (or acceptor), it significantly influences the OH(I) (or donor). As the hydrogen bonding becomes stronger from a 1,2- to a 1,4-diol, the fundamental band of the OH-stretching shifts downwards by from about 50 to 140 cm(-1), and the overtone band markedly decreases in intensity, although the effect on the intensity and bandwidth of the fundamental band varies among 1,2-, 1,3- and 1,4-diols. The quantum-mechanically calculated normal frequencies of the acceptor and donor OH groups in the hydrogen-bonded ring are in good agreement with the observed frequencies. The calculated interatomic distance between the O of an acceptor OH and the H of a donor OH is the shortest for a 1,4-diol, which is consistent with the largest frequency shift caused by the hydrogen bonding.
Iwamoto
Reikichi
R
KRI Inc., Energy and Processing Research Laboratory, Chudoji-minamimachi 134, Shimogyoku, Kyoto 600-8813, Japan. iwamoto@kri-inc.jp
Matsuda
Toshihiko
T
Kusanagi
Hiroshi
H
D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared
D006878:Hydroxides; C031356:hydroxide ion