PRODUCTION OF NCL(A) BY THERMAL-DECOMPOSITION OF CLN3

Thermal decomposition of ClN3 by pulsed CO2 laser pyrolysis has been investigated by using SF6 as a sensitizer. The electronically excited decomposition products, NCl(a) and NCl(b), were monitored by absolute time-resolved emission spectroscopy while ClN3 was followed by ultraviolet absorption. The results indicate a higher barrier to dissociation of ClN3 than FN3, consistent with ab initio calculations, and an NCl(a) yield of order unity, based on a nominal 0.7/s radiative rate for the NCl(a-X) transition. Studies of simultaneous dissociation of FN3 and ClN3 have also revealed that NCl(a), when coproduced with NF(a), upconverts the latter species to NF(b) efficiently (in the presence of trace I2) and cooperatively pumps the IF(B) state (upon addition of CF3I) by an energy pooling mechanism that does not involve NF(b) as an intermediate. These results indicate a potential for development of chemical lasers that operate on either the NF(b→X) or IF(B→X) transitions at visible wavelength. © 1990 American Chemical Society.