Carbon vibrationally excited, emission from

Electronic excitation from atom-transfer reactions appears to be relatively uncommon, with most such reactions producing chemiluminescence from vibrationaHy excited ground states (188—191). Examples include reactions of oxygen atoms with carbon disulfide (190), acetylene (191), or methylene (190), all of which produce emission from vibrationaHy excited carbon monoxide. When such reactions are carried out at very low pressure (13 mPa (lO " torr)), energy transfer is diminished, as with molecular beam experiments, so that the distribution of vibrational and rotational energies in the products can be discerned (189). Laser emission at 5 p.m has been obtained from the reaction of methylene and oxygen initiated by flash photolysis of a mixture of SO2, 2 2 6 (1 )-... 

By using a time-of-flight method to distinguish between the C, C2 and C3 components of a thermal (2550 K) carbon beam, it was possible to measure the visible emission from the CN (B2S+) product of the four-centre exchange reaction C2 + NO [614], Vibrational states up to v - 4 are populated and can be fitted by a temperature of TvIb 6900 ( 700) K. The rotational excitation of the CN (B2 +) decreases as the vibrational excitation increases (7000 > Trot > 3500 K for 0 < i> < 4). An information theory analysis of the data shows agreement of the experimental distributions with the prior forms. 

Determination of the temperatures reached in cavitating bubbles has remained a difficult experimental problem. As a spectroscopic probe of the cavitation event, MBSL provides a solution. High-resolution MBSL spectra from silicone oil under Ar have been reported and analyzed. The observed emission comes from excited states of diatomic carbon (C2) and has been modeled with synthetic spectra as a function of rotational and vibrational temper-... 

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