14644-45-2Relevant articles and documents
Laser spectroscopy and dynamics of the jet-cooled AsH2 free radical
He, Sheng-Gui,Clouthier, Dennis J.
, p. 1 - 9 (2009/02/02)
The A2A1-X2B1 electronic transition of the jet-cooled AsH2 free radical has been studied by laser-induced fluorescence (LIF), wavelength-resolved emission, and fluorescence lifetime measurements. The radical was produced by a pulsed electric discharge through a mixture of arsine (AsH3) and high pressure argon at the exit of a pulsed valve. Nine vibronic bands wereidentified by LIF spectroscopy in the 505-400 nm region, including a lo ng progression in the bending mode and two bands (101 and 101201) involving the excited state As-H symmetric stretch. Single vibronic level emission spectra showed similar activity in the bending and symmetric stretching frequencies of the ground state. High-resolution spectra of the 000 band exhibited large spin splittings and small, resolved arsenic hyperfine splittings, due to a substantial Fermi contact interaction in the excited state. The rotational constants obtained in the analysis gave effective molecular structures of r″0 = 1.5183(1) ?, θ″0=90.75(1) ° and r′0=1.4830(1) ?, θ′0= 123.10(2)°. The excited state fluorescence lifetimes vary dramatically with rovibronicstate, from a single value of 1.4 μs to many with lifetimes less tha n 10 ns, behavior which the authors interpret as signaling the onset of a predissociative process near the zero-point level of the ground state.
Submillimeter-wave spectrum of the AsH2 radical in the 2B1 ground electronic state
Fujiwara, Hideo,Kobayashi, Kaori,Ozeki, Hiroyuki,Saito, Shuji
, p. 5351 - 5355 (2007/10/03)
The pure rotational spectrum of the AsH2 radical in its 2B1 ground electronic state was observed for the first time by microwave spectroscopy. The AsH2 radical was generated in a free-space cell by dc-glow discharge of a mixture of H2 and O2 gases over arsenic powder. Fifty-five fine and hyperfine components of six rotational transitions were measured in the frequency region of 304-374 GHz, and were analyzed by least-squares methods. Molecular constants, including the rotational constants, the centrifugal distortion constants, the spin-rotation coupling constant incorporating the centrifugal distortion term, and the hyperfine coupling constants associated with the arsenic and hydrogen nuclei, were precisely determined. The bonding in AsH2 was discussed on the basis of the hyperfine coupling constants, first determined in the present study.
