TY - JOUR
T1 - Near-infrared high resolution diode laser spectrum of the CH2 b̃1B1 ← ã1A1 transition
AU - Fockenberg, Christopher
AU - Marr, Andrew J.
AU - Sears, Trevor J.
AU - Chang, Bor Chen
N1 - Funding Information:
The authors thank Professor Per Jensen for providing details of his calculations of CH2 energy levels. The experimental work was carried out at Brookhaven National Laboratory under Contract DE-AC02-76CH00016 with the U.S. Department of Energy and support by its Division of Chemical Sciences, Office of Basic Energy Sciences. B.C.C. also thanks the National Science Council, Taiwan, for its support of this work under Grant NSC86-2112-M-008-032-T.
PY - 1998/2
Y1 - 1998/2
N2 - A new diode laser-based spectrometer operating at wavelengths close to 1 μm has been constructed for transient absorption measurements in the gas phase. Using a dual beam detection system for noise cancellation, the minimum detectable absorption was found to be 1 × 10-4 in 0.5 μsec. The sensitivity of the instrument is illustrated by the observation of previously undetected spectra of singlet methylene (CH2) between 9780 and 10070 cm-1. Rovibronic transitions involving two Ka = 1 levels, nominally associated with v2(bent) = 1 and 2, in the upper, b̃1B1, state have been assigned. These levels are the lowest so far observed for methylene in this electronic state and their positions provide new information on the shape of the bending potential for the molecule at energies approaching that at which the two lowest singlet states (ã1A1 and b̃1B1) of the molecule become degenerate at the linear configuration.
AB - A new diode laser-based spectrometer operating at wavelengths close to 1 μm has been constructed for transient absorption measurements in the gas phase. Using a dual beam detection system for noise cancellation, the minimum detectable absorption was found to be 1 × 10-4 in 0.5 μsec. The sensitivity of the instrument is illustrated by the observation of previously undetected spectra of singlet methylene (CH2) between 9780 and 10070 cm-1. Rovibronic transitions involving two Ka = 1 levels, nominally associated with v2(bent) = 1 and 2, in the upper, b̃1B1, state have been assigned. These levels are the lowest so far observed for methylene in this electronic state and their positions provide new information on the shape of the bending potential for the molecule at energies approaching that at which the two lowest singlet states (ã1A1 and b̃1B1) of the molecule become degenerate at the linear configuration.
UR - http://www.scopus.com/inward/record.url?scp=0032002405&partnerID=8YFLogxK
U2 - 10.1006/jmsp.1997.7476
DO - 10.1006/jmsp.1997.7476
M3 - 期刊論文
AN - SCOPUS:0032002405
SN - 0022-2852
VL - 187
SP - 119
EP - 125
JO - Journal of molecular spectroscopy
JF - Journal of molecular spectroscopy
IS - 2
ER -