TY - JOUR
TI - Low-frequency Raman spectroscopy of n-alcohols. LAM vibration and crystal structure
AU - Soutzidou, M.
AU - Glezakou, V.-A.
AU - Viras, K.
AU - Helliwell, M.
AU - Masters, A.J.
AU - Vincent, M.A.
JO - JOURNAL OF PHYSICAL CHEMISTRY B: CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES, AND BIOPHYSICAL (THE)
PY - 2002
VL - 106
TODO - 17
SP - 4405-4411
PB - 
SN - 1089-5647
TODO - 10.1021/jp025586l
TODO - Longitudinal acoustic modes (LAM), Crystal structure;  Dimers;  Hydrogen bonds;  Raman spectroscopy, Alcohols
TODO - Low-frequency Raman spectra of even and odd n-alcohols have been recorded. The longitudinal acoustic modes (LAM) are described, and the effects of hydrogen-bonding, chain length, and temperature on the frequencies of these vibrations are discussed. The frequencies of the LAMs are interpreted in terms of the one-dimensional crystal model of Minoni and Zerbi and also ab initio calculations on isolated single chains. The low-frequency LAM-1 mode of the hydrogen-bonded dimer exhibited an odd-even effect, and to gain insight into this, the crystal structures of the C17 and C20 alcohols were determined by single-crystal X-ray diffractometry. C17H35OH packs in the β form, with half the oxygen atoms trans and half gauche, with respect to the alkyl chains. C20H41OH adopts an all trans conformation and the packing is in the γ form. The hydrogen-bonding interactions differ in the two structures. We therefore ascribe the odd-even effect in the LAM-1 frequencies to an odd-even effect in crystal structure.
ER -