ISSN:
0030-493X
Schlagwort(e):
Chemistry
;
Analytical Chemistry and Spectroscopy
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The electron-impact and field ionisation spectra of nineteen di- and tetracyanopyrazines are presented. The use of high resolution mass measurement and metastable analysis allows the proposal of some general fragmentation mechanisms. The 5,6-disubstituted (alkyl or arene) 2,3-dicyanopyrazines examined show, apart from a less important loss of the nitrile and dicyano groups, fragmentation of the heterocyclic system directed by the nitrogen atoms. In contrast, anellation in the 5,6-position, leads only to loss of the nitrile and dicyano groups being observed. These general fragmentation mechanisms are also observed for the tetracyanopyrazines examined. A comparison of di- and tetracyanobenzene with five ring heterocycles containing four cyano groups shows that fragmentation of nitrile groups is greatly dependent upon the aromaticity of the cyclic system.
Zusätzliches Material:
8 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/oms.1210100204
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