Spectroscopy of high vibrational levels in pyramidal molecules: C-H stretching overtones of N(CH3)3, P(CH3)3, and as(CH3)3

Carlos Manzanares I*, N. L.S. Yamasaki, Eric Weitz

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)3959-3969
Number of pages11
JournalJournal of physical chemistry
Issue number15
StatePublished - 1987

ASJC Scopus subject areas

  • Engineering(all)
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Spectroscopy of high vibrational levels in pyramidal molecules: C-H stretching overtones of N(CH<sub>3</sub>)<sub>3</sub>, P(CH<sub>3</sub>)<sub>3</sub>, and as(CH<sub>3</sub>)<sub>3</sub>'. Together they form a unique fingerprint.

Cite this