15194-15-7Relevant academic research and scientific papers
Generation and high-resolution photoelectron spectroscopy of small organic radicals in cold supersonic expansions
Willitsch, Stefan,Dyke, John M.,Merkt, Frederic
, p. 1152 - 1166 (2003)
A general method of generating radicals in cold supersonic expansions in the gas phase is presented. The method relies on excimer laser photolysis of suitable precursor molecules in a thin quartz capillary mounted at the orifice of a pulsed gas nozzle and can easily be combined with vacuum-UV photoionization mass spectrometry and high-resolution photoelectron spectroscopy to study the reactivity and the rovibronic energy level structure of neutral radicals and their ions, as well as to determine highly accurate adiabatic ionization energies. The characteristics of the radical source are described in detail, and its performance is illustrated by mass spectrometric and high-resolution photoelectron spectroscopic investigations of NH2, CH2, CH3, C2H, C2H3, and C2H5. The radical source is not only suitable to produce cold samples (rotational temperature of ca. 30 K) of radicals of moderate reactivity, such as NH2, CH3, or C2H5, but it is also useful to prepare highly reactive radicals (e.g., C2H) for spectroscopic investigations.
Difference frequency laser spectroscopy of the ν3 fundamental band of NH2+
Okumura, M.,Rehfuss, B. D.,Dinelli, B. M.,Bawendi, M. G.,Oka, T.
, p. 5918 - 5923 (1989)
The ν3 band of NH2+ in the 3B1 ground electronic state was observed in direct absorption with a tunable difference frequency laser spectrometer in the 3 μ region, using velocity modulation detection.NH2+ and NH3+ ions were generated in an ac discharge of He and NH3, or of He, N2, and H2.Fifty-three rovibrational transitions were measured and fit to a triplet A-reduced Hamiltonian to determine rotational, centrifugal distortion, and spin-rotation constants.The band origin was found to be ν0=3359.932 cm-1, in excellent agreement with a recentcalculation of Jensen, Bunker, and McLean.Indirect evidence from the spectrum suggested that NH2+ is quasilinear, but selection rules prevented a determination of the A rotational constant.
