Triplet state optical and ODMR spectra of dimethyl oxalate
作者:J. P. Arrington、J. F. Landry、D. S. Tinti
DOI:10.1021/j150601a008
日期:1981.1
Cyclization of dimethyl oxalate upon electron impact
作者:J. G. Liehr、E. A. Larka、J. H. Beynon
DOI:10.1002/oms.1210160110
日期:1981.1
AbstractIsotope labelling experiments and also consecutive fragmentation investigations of metastable ions, a novel technique in mechanistic studies, have been carried out to elucidate structure and genesis of the m/z 45 ions from dimethyl oxalate as well as dimethyl carbonate. It is shown that the formation of the m/z 45 ions, \documentclassarticle}\pagestyleempty}\begindocument}$ \rmCH}}_\rm3}} \mathop \rmO}}\limits^\rm + }} = \rmCH}}_\rm2}} $\enddocument}, in the mass spectra of these compounds arises via single step processes. Mechanisms involving hydrogen transfer and subsequent formation of cyclic intermediates which then collapse to give \documentclassarticle}\pagestyleempty}\begindocument}$ \rmCH}}_\rm3}} \mathop \rmO}}\limits^\rm + }} = \rmCH}}_\rm2}} $\enddocument} directly from molecular ions are suggested. No evidence was found for a two‐step fragmentation route to m/z 45 from the molecular ions of either dimethyl oxalate or dimethyl carbonate.
Spin density distribution in dialkyl oxalate radical anions
作者:P. Brix、D. Helling、J. Voss
DOI:10.1002/mrc.1260260410
日期:1988.4
The isotropic and anisotropic ESR spectra of dialkyl oxalate radical anions, including derivatives which were labelled with 13C or 17O in the carbonyl and 2H or 13C in the alkyl groups, were measured. The spin density distribution as determined from the experimental nuclear hyperfine couplingconstants agrees very well with MNDO‐CI calculations. As a consequence of the strictly planar structure of