Negative ion mass spectrometry and stereochemistry of organic compounds. 7. Phenoxybenzyl esters of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid

Conclusions The stereospecific fragmentation of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid -cyano-3-phenoxybenzyl ester was found under conditions of resonant capture of electrons of epithermal energies with dissociation of HCN. The stereospecific collection of fragment ions allows not only the identification of one of the diastereoisomers, but also the quantitative (5%) determination of it in a mixture of racemates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 291–294, February, 1989.     

Fragmentation of valine and proline in resonant free electron capture reactions

The processes of resonant electron capture by molecules of valine and proline were studied. The main dissociative decay channels of molecular ions and the structures of fragment ions were established. The reactions of simple bond cleavage and H-shift rearrangement processes were revealed. The dissociative electron attachment cross-sections for [M - H]^? ions were measured in the region of 1.25 eV. The metastable decay of [M - H]^? ions were found in the energy region of 4.5?C8 eV. The structures of decomposing parent ions were determined using the statistical model of metastable fragmentation.     

Processes of hydrogenation of trifluoromethylfullerenes in the mass spectrometer ion source

The processes of hydrogenation of a mixture of trifluoromethylfullerenes was studied in situ by means of positive-and negative-ion mass spectrometry. The effective addition of 1, 5, and 11 hydrogen atoms was revealed. The appearance energies of positive trifluoromethylfullerene ions C ₆₀ (CF₃) _n ⁺ (n = 1–8) and C₆₀(CF₃) _n H⁺ (n = 1, 3, 5, 7) were determined.