Abstract
A step-scan Fourier-transform infrared spectrometer was used to detect time-resolved spectrum of ClSO. The rotational structure with the Q-branch at 1162.9 cm -1 was revealed by a spectrum with a resolution of 0.3 cm -1 . The geometry, vibrational and rotational parameters of ClSO were predicted by calculations with density-functional theory. The results show that the CISO produced from photolysis of Cl 2 SO at 248 nm is internally hot.