Knowledge Bank

The infrared and Raman spectra of gaseous and solid nitrosyl chloride, ONCl, have been recorded from 30 to $2200cm-1$. In the spectrum of the gas, the fundamentals $v2$ and $v3$ for the isotopic species $ON37Cl$ have been determined from the Raman spectra. Large shifts from gaseous frequencies were observed for the solid material. New force constants have been calculated and compared to previously reported constants. The pure infrared rotational spectrum of ONCl has been recorded (20 to $120cm-1$) and interpreted in terms of a slightly asymmetric prolate top with centrifugal distortion. Two series of seventeen and ten sharp Q-branches were observed for the ground state and first excited state, respectively. $A-B¯$ and $Dk$ have been determined for the two states in this study. The vibrational-rotational structure for two fundamentals was analyzed and excited vibrational state rotational constants have been obtained. Band centers were determined to be at 595.79 and $331.97cm-1$ for $v2$ and $v3$, respectively, for $ON35Cl$.