Products of the quenching of NO A super(2) capital sigma super(+) (v= 0) by N sub(2)O and CO sub(2)

• Published in: Physical chemistry chemical physics : PCCP Vol. 15; no. 7; pp. 2554 - 2564
• Main Authors: Burgos Paci, Maximiliano A, Few, Julian, Gowrie, Sarah, Hancock, Gus
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: Bonding; Carbon dioxide; Channels; Excitation; Fourier transforms; Infrared; Nitrous oxides; Quenching
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c2cp43878j

Collisional quenching of NO A super(2) capital sigma super(+) (v= 0) by N sub(2)O and CO sub(2) has been studied through measurements of vibrationally excited products by time resolved Fourier transform infrared emission. In both cases vibrationally excited NO X super(2) capital pi (v) is seen and quantified in levels v greater than or equal to 2 with distributions which are close to statistical. However the quantum yields to produce these levels are markedly different for the two quenchers. For CO sub(2) such quenching accounts for only ca.26% of the total: for N sub(2)O it is ca.85%. Far more energy is seen in the internal modes of the CO sub(2) product than those of N sub(2)O. The results are rationalised in terms of cleavage of the N sub(2)-O bond being dominant in the latter case, with either a similar O atom production or a specific channel producing almost exclusively NO in low vibrational levels (v= 0,1) for quenching by CO sub(2). Minor reactive channels yielding NO sub(2) are seen in both cases, and O( super(1)D) is observed with low quantum yield in the reaction with N sub(2)O. The results are discussed in terms of previous models of the quenching processes, and are consistent with the very high yield of NO X super(2) capital pi (v= 0) previously observed by laser induced fluorescence for quenching of NO A super(2) capital sigma super(+) (v= 0) by CO sub(2).