TY - JOUR
T1 - Spectroscopy of high vibrational levels in pyramidal molecules
T2 - C-H stretching overtones of N(CH3)3, P(CH3)3, and as(CH3)3
AU - Manzanares I, Carlos
AU - Yamasaki, N. L.S.
AU - Weitz, Eric
PY - 1987
Y1 - 1987
N2 - Photoacoustic spectra of the overtones of the C-H stretches of N(CH3)3, P(CH3)3, and As(CH3)3 in the gas phase are reported. The observed spectral features are assigned on the basis of the local-mode model. Two bands are observed for each overtone which are assigned to nonequivalent methyl C-H bonds. The higher energy absorption band in each overtone region (Δν = 5, 6, and 7) is assigned to the out-of-plane methyl C-H bonds while the lower energy absorption band is assigned to the in-plane C-H bond. Deconvolution of the overtone bands for Δν(C-H) = 5, 6, and 7 provides additional information with respect to peak position, profile, and line width of the overtone absorptions. Local-mode harmonic frequencies (ωe) and anharmonicities (ωexe) are obtained from an analysis of the spectra. Data suggest that the major factor contributing to the width of P(CH3)3 and As(CH3)3 overtone absorptions is the rotational envelope of the molecule while line widths obtained for N(CH3)3 indicate there is also a major contribution to the width from homogeneous broadening.
AB - Photoacoustic spectra of the overtones of the C-H stretches of N(CH3)3, P(CH3)3, and As(CH3)3 in the gas phase are reported. The observed spectral features are assigned on the basis of the local-mode model. Two bands are observed for each overtone which are assigned to nonequivalent methyl C-H bonds. The higher energy absorption band in each overtone region (Δν = 5, 6, and 7) is assigned to the out-of-plane methyl C-H bonds while the lower energy absorption band is assigned to the in-plane C-H bond. Deconvolution of the overtone bands for Δν(C-H) = 5, 6, and 7 provides additional information with respect to peak position, profile, and line width of the overtone absorptions. Local-mode harmonic frequencies (ωe) and anharmonicities (ωexe) are obtained from an analysis of the spectra. Data suggest that the major factor contributing to the width of P(CH3)3 and As(CH3)3 overtone absorptions is the rotational envelope of the molecule while line widths obtained for N(CH3)3 indicate there is also a major contribution to the width from homogeneous broadening.
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U2 - 10.1021/j100299a009
DO - 10.1021/j100299a009
M3 - Article
AN - SCOPUS:0842321608
VL - 91
SP - 3959
EP - 3969
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 15
ER -