Knowledge Bank

The reaction of $NFCI2$ with metastable argon atoms was investigated. When $NFCI2$ was admitted to a stream of argon metastables ($\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}P2$), visible and UV emission was observed. Two sources of the visible emission were identified. A sharp peak at 528 nm was assigned to the $\Delta$v=0 sequence band of the $b1\Sigma 1\leftarrow X3\Sigma$ transition in NF and a peak at 664 nm was assigned to the $\Delta v=0$ sequence band of the $\Sigma +-X2\Sigma$ transition in NCI. The $\Delta v=-1,+1,+2$, and +3 sequence bands of the NCI b-X transition were also observed with up to $v\prime =12$ levels populated. The vibrational excitation in the NF and NCl fragments has implications for the geometry of the excited state of $NFCI2$ formed in the $Ar(3P2)+NFCl2$ reaction. The UV emission spectrum consisted of two bands with maxima at 256 nm and 198 nm. The intensity distribution of the UV emission was identical to the emissionthat was observed when $CI2$ was added to the stream of argon metastables and was assigned to electronically excited $Cl2$ formed via $Cl2+Ar(3P2$) . The source of the $Cl2$ is either $Cl2$ is either $Cl2$ contamination in the $NFCL2$ sample, or $Cl2$ formed during the reaction of $NFCI2$ with $Ar3P2$. To examine the energetics of the $NFCl2+Ar(3P2)$ reaction. G1 and G2 methods were used to calculate the $\Delta Hform$ of $NFCI2$.