Journal of Chemical Physics, Vol.100, No.11, 7916-7927, 1994
High-Resolution Study of Methanes 3-Nu(1)+nu(3) Vibrational Overtone Band
Methane’s 3v(1)+v(3) vibrational overtone spectrum has been recorded at room temperature, 100 KI and approximately 15 K using laser intracavity photoacoustic and molecular beam techniques. Although rotational congestion renders the room temperature spectrum undecipherable, the 100 K data suggest possible rovibrational assignments that are confirmed in the 15 K spectrum;by their individual temperature dependences. Molecular beam Stark spectroscopy is used to unambiguously identify the E symmetry components of the R(2), P(2), and e (2) transitions. These results indicate the presence of several other bands whose intensities are derived through interactions with the 3v(1)+v(3) vibrational overtone transition. Quantitative analysis of these interactions suggests a bright state origin of 11 277.0 cm(-1).
Keywords:EXTENSIVELY PERTURBED SPECTRA;MOLECULAR EIGENSTATE SPECTRUM;DOUBLE-RESONANCE OBSERVATION;GROUND-STATE;FORCE-FIELD;ABSORPTION SPECTROSCOPY;TETRAHEDRAL MOLECULES;DIRECT DECONVOLUTION;ROTATIONAL ANALYSIS;LASER-ABSORPTION