- Inherent asymmetry of constitutionally equivalent methyl groups in the H/D equilibration of n- and i-C3H7Fe(OH)+ complexes
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Transiently formed, constitutionally identical methyl groups remain inequivalent in the course of an n-propyl?isopropyl isomerization (see scheme) operative in Fe÷-mediated dehydration of propanols. The reversibility of the β-hydrogen transfer steps is addressed by examination of the H/D equilibration in metastable complexes of Fe+ with a set of selectivity deuterated propanols by using tandem mass spectrometry.
- Trage, Claudia,Zummack, Waltraud,Schroeder, Detlef,Schwarz, Helmut
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- Intramolecular Thermal Motions in Liquid n-Propanol (+ Glycerol), A Proton Magnetic Relaxation Study. 2
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The proton magnetic relaxation times T1 and T2 of the four n-propanol species HOC3D7, DOCH2CD2CD3, DOCD2CH2CD3, and DOCD2CD2CH3 have been measured at the resonance frequency ν = 12 MHz as a function of the temperature in the range 80 1 measurements were performed at a second frequency, ν = 48 MHz, as well.Further measurements of the same general kind were done on the mixtures n-propanol + 50 mol percent glycerol (glycerol-d5 and -d8) and n-propanol + 70 mol percent glycerol (glycerol-d5 and -d8).Isotopic dilution measurements with constant content of propanol and varying degree of deuteration were made to obtain the intramolecular relaxation rates.The proton NMR spectra of the four propanol species were recorded at T = 130 K.From all these data correlation times for the various proton-proton vectors were derived.It turned out that to each motion a slow and a fast mode contribution exists, however, the results are not compatible with the model of a molecule as a system of rigid bodies connected by axes about which rotation occurs.A formal description and interpretation is given involving the molecule concept without the presupposition of a microscopic rigid body.
- Poeschl, M.,Hertz, H. G.
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- CYCLOPROPYL MODULATORS OF P2Y12 RECEPTOR
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The present invention relates to new cyclopropyl modulators of P2Y12 receptor activity, pharmaceutical compositions thereof, and methods of use thereof.
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Page/Page column 53
(2011/02/24)
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- Anwendung der Perdeuteroallyl Schutz-Gruppe
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Facile and straightforward transformations of propynoic acid into perdeuterated allyl bromide are described.The advantage of a pentadeuteroallyl protection for the 1H-N.M.R. structure elucidation of complex carbohydrate derivatives is demonstrated in the
- Thiem, Joachim,Mohn, Holger,Heesing, Albert
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p. 775 - 778
(2007/10/02)
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