Deuteration—continued studies

Expensive and complex instrumentation. Moderate to poor sensitivity with continuous wave (scanning) instruments, but greatly enhanced by Fourier transform instruments. Limited range of solvents for studying proton spectra unless they are deuterated. 

I wish to relate my continued collaboration with Fabian Gerson of the University of Basel in Switzerland on ESR studies. One of our recent cooperative explorations involved the radical anions of the nonplanar tribenzo[fl,c,e]cyclooctene 25 as well as its nonplanar and planar derivatives. During this investigation, which actually lasted for many years, Gerson required some deuterated derivatives for an explicit... 

Instrumentation. The experimental setup is similar to that employed for in situ X-ray diffraction. The material under investigation is pressed into a thin sheet and mounted together with suitable counter and reference electrodes into a silica cell. In order to decrease the large incoherent scattering contributions from protons in aqueous electrolyte solutions, deuterated solutions are used. In a typical study, the reaction mechanism of Ni(OH)2 (employed in nickel accumulators) was studied with neutron powder diffraction NPD [46]. A direct and continuous structural transformation of both the y- and jS-NiOOH phases into j8-Ni(OH)2 was observed during reduction with no direct relationship or discontinuity related to the transition from the first discharge electrode potential to the second one, which was located about 0.4 V lower. 

In fact, one early problem that continues to plague many studies is that deuterated polyethylene tends to phase-separate from ordinary, protonated polymer, even though they are chemically identical. The cause has been related to slightly different crystallization rates owing to poly-deuteroethylene melting 6°C lower than ordinary polyethylene. 

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