Gas-Phase Reactivities and Interchromophoric Effects in 1,n -Dicarbazolylalkane Cations and Related Species

Document Type

Article

Publication Date

12-1991

Publication Title

Journal of Organic Chemistry

Abstract

The behavior of gaseous cations derived from electron ionization (20 and 70 eV) and methane chemical ionization (CI) of 1,n-dicarbazolylalkanes la-5a (where n = 1-5 methylene units, respectively) and the corresponding 3-nitro derivatives lb-Sb was examined using mass spectrometry. An iminium ion (mlz 180) is the major fragment from all 1-5 examined with the exception of 4a, for which CI affords predominantly a pyrrolidinium ion (m/z 222) by displacement of carbazole. Compounds la and lb exhibit little [MI'+ and [M + H]+ and undergo the most extensive fragmentation. Ethylated iminium ion (mlz 208) is observed from both la and lb under CI conditions, indicating operation of an interannular hydrogen shift. Compound 3a fragments least, consistent with an exceptional, although small, stabilization for the parent ions of this derivative.

DOI

10.1021/jo00025a015

Volume

56

Issue

25

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