Absorption spectra of AsH2 radical in 435-510Â nm by cavity ringdown spectroscopy

The absorption spectra of jet-cooled AsH2 radicals were recorded in the wavelength range of 435-510 nm by cavity ringdown spectroscopy. The AsH2 radicals were produced by pulsed DC discharge in a molecular beam of a mixture of AsH3, SF6, and argon. Seven vibronic bands with fine rotational structures have been identified and assigned as the 000, 20n, and 21n (n = 1-3) bands of the A∼2A1-X∼2B1 electronic transition. Based on the previous studies of AsH2 radical, rotational assignments and rotational term values for each band were obtained, and the molecular parameters including vibrational constants, rotational constants, centrifugal distortion constants, and spin-rotation interaction constants were also determined.