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Towards a Fully Conjugated, Double‐Stranded Cycle: A Mass Spectrometric and Theoretical Study
Author(s) -
Denekamp Chagit,
Etinger Alexander,
Amrein Walter,
Stanger Am,
Stuparu Mihaiela,
Schlüter A. Dieter
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701098
Subject(s) - chemistry , mass spectrometry , isomerization , dissociation (chemistry) , collision induced dissociation , ion , alkyl , conjugated system , mass spectrum , computational chemistry , analytical chemistry (journal) , organic chemistry , chromatography , tandem mass spectrometry , polymer , catalysis
The two compounds, 1 and 5 , are investigated by means of collision‐induced dissociation experiments by using ion cyclotron resonance mass spectrometry and other mass spectrometric techniques as to their ability to act as precursors for the fully unsaturated double‐stranded target compound 2 . These experiments are complemented by flask‐type pyrolyses of 5 , the products of which are analyzed by mass spectrometry. For 1 , no conditions were found under which the expected molecular ion of 2 at m / z 932 appeared, however, for its derivative 5 this was possible. This interesting finding is not in contradiction with the chemical structure of the long sought for compound 2 but calculations suggest that this compound may have isomerized into one where the conjugation is interrupted by hydrogen shift from the solubilizing alkyl chains into the cycle's perimeter. The key driving force for such an isomerization would be the considerable relief of strain energy.