Knowledge Bank

Laser induced fluorescence spectroscopy of IF isolated in an Argon matrix at 12K has been investigated. Following laser excitation at 355 nm, long-lived emission is observed in the near infra-red region. This emission, resolved with a monochromator, shows a vibrational progression at wavelengths of 721 nm up to 1333 nm. Spectral analysis indicates that the emission comesfrom the lowest vibrational level of a new low lying electronic state and terminates on the vibrational levels $v\prime \prime =12$ up to $v\prime \prime =25$ of the ground state $(X\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +)$. This analysis provides an estimate for Te of about $20,800cm-1$ and an approximate equilibrium distance of 2.5 \AA. The lifetime for this emission was also measured and found to be 7 msec. Details of these experiments and a possible assignment for this new low lying electronic state will be presented.