Low-energy fragmentations of five isomeric [H3, C, N, O2] +· ions

✍ Scribed by M. Sirois; J. L. Holmes; C. E. C. A. Hop

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 614 KB
• Volume: 25
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210250310

✦ Synopsis

The low-energy fragmentation characteristics of the [H, ,C,N,O,]+' isomers [H,CNOJ+' (a), [H,C=N(O)OHJ+' (b), [H,CONO]+' (c), [HC(O)NHOH]+' (d) and [HC(OH)=NOH]+' (e) were studied in detail by metastable ion mass spectrometry. In agreement with most earlier observations, appearance energy measurements established the potential energy surface of the isomers rr, b and c, showing the intricate interrelations between them. It was concluded that a isomerizes into b prior to fragmentation by loss of 'OH and H,O and into c before loss of 'H and H,CO' moreover, the reverse reactions do not take place on the metastable time-frame. The dominant metastable process for isomers d and e (obtained via HCN loss from glyoxime) was generation of [H,NOHI+'. For isomer e this process was proposed to involved a rate-determining isomerization into d. It was concluded that isomers d and e do not intercommunicate with ions a, b and c prior to fragmentation. Neutralization-reionization mass spectrometry indicated that the enol form of formohydroxamic acid as well as the keto counterpart are stable in the gas phase.