90047-89-5Relevant academic research and scientific papers
Thermal isomerizations of 1-13C-2,2,3,3-d4- cyclopropane to isotopically labeled trimethylene diradicals, 1-propylidenes, and propenes
Baldwin, John E.,Day, Linda S.,Singer, Stephanie R.
, p. 9370 - 9371 (2005)
The gas-phase thermal isomerizations of 1-13C-2,2,3,3-d4-cyclopropane lead to isotopically labeled propenes characteristic of both the traditional reaction mechanism involving a trimethylene diradical intermediate and a previously predicted, but never observed, path involving rate-limiting conversion of the cyclopropane to singlet 1-propylidenes, followed by a [1,2]-deuterium shift. The isomerizations give mixtures of both 1-13C-2,3,3,3-d4-propene and 1-13C-1,2,3,3-d4-propene, products characteristic of the two mechanisms that are clearly observable by 13C{1H} NMR spectroscopy. Copyright
Structure and Dynamics of Cyclopropane in Solution by Nuclear Magnetic Resonance Coupled Relaxation
Brown, Mark S.,Mayne, Charles L.,Grant, David M.,Chou, T. C.,Allred, Evan L.
, p. 2708 - 2713 (2007/10/02)
The spin-lattice relaxation of selectively labeled cyclopropane-1-13C-2,2,3,3-d4 (13CH2C2D4) dissolved in CD2Cl2 has been studied with carbon-13 NMR.Selctive and nonselective ? pulses were applied to the carbon and proton transitions of this AX2 spin system and partially relaxed carbon-13 spectra were obtained for various evolution periods after the pulse.All experiments were performed at -81.5, -60, -20, and +20 deg C.The data were analyzed in terms of a small-step rotational diffusion model for the rotational reorientation.The reorientation at -81.5 and -60 deg C may be characterized by two diffusion coefficients.The unique axis lies parallel to the C3 axis of cyclopropane.At -20 and +20 deg C, only one diffusion parameter is obtained.Values obtained for the proton-proton distance at the lower temperatures agree reasonably well with values in the literature but become too large at the higher temperatures.Small but negative values for the carbon autocorrelation random field term jC are observed at the lower temperatures.These results indicate that as temperature increases, the molecule enters a motional regime where the dipolar mechanisms become less efficient, spin rotation becomes more important, and greater uncertainty exits in the small-step motional model used to interpret the data.
