Results 141 to 150 of about 1,071,828 (189)

Coupling constants nitrogen-15-nitrogen-15 and nitrogen-15-hydrogen in phenylhydrazones forming hydrogen bond

Collection of Czechoslovak Chemical Communications, 1981
Absolute values of the coupling constants 1J(15N15N), 1J(15NH) of six phenylhydrazones forming hydrogen bond, 2J(15N15NH) of four, and 4J(15NH) of two phenylhydrazones have been determined. Three coupling constants 1J(15N15N) have been obtained from the nitrogen-15 monolabelled compounds by measuring the other nitrogen at natural abundance.
Antonín Lyčka, Dobroslav Šnobl
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Nitrogen-15: Microbiological Alteration of Abundance

Science, 1968
The abundance of N 15 relative to N 14 is significantly altered during experiments in vitro in which nitrate and nitrite are microbiologically reduced to nitrogen gas. In all studies to date, N 14 O 3 - and N 14
R P, Wellman, F D, Cook, H R, Krouse
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ChemInform Abstract: NITROGEN‐15 ‐ NITROGEN‐15 COUPLING CONSTANTS AND ROTATIONAL BARRIERS OF NITROSAMINES

Chemischer Informationsdienst, 1984
AbstractDie Verbindungen (I)‐(V), in denen die NO‐Gruppe "N‐markiert (99%) ist, werden "N‐ NMR‐spektroskopisch untersucht.
H. BANDMANN, P. HEYMANNS, C. SIEM, P. RADEMACHER   +3 more
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Nitrogen-15 magnetic resonance spectroscopy. XIV. Natural-abundance nitrogen-15 chemical shifts of amines

Journal of the American Chemical Society, 1972
It has been found possible to measure the shifts of a variety of amines to an accuracy of 0.2 ppm with the isotope at its natural-abundance level. Successful observation of these resonances with our existing equipment is dependent on a favorable nuclear Overhauser effect arising from irradiation of the protons.
Lichter, Robert L., Roberts, John D.
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Nitrogen‐15 NMR spectroscopy: Nitrogen‐15 chemical shifts of alkylthioureas

Magnetic Resonance in Chemistry, 1991
AbstractNitrogen‐15 chemical shifts of alkylthioureas in dimethylsulphoxide and pyridine are reported.
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Nitrogen-15 chemical shifts and carbon-13-nitrogen-15 coupling constants of cyanide complexes

Inorganic Chemistry, 1982
The /sup 13/C NMR spectra of cyanide complexes have been reported by Hirota et al. and Pesek et al. However, no reports have been found concerning /sup 15/N resonances and C-N nuclear-spin coupling constants, J/sub C-N/, for cyano complexes. The data for J/sub C-N/ and /sup 15/N and /sup 13/C resonances may be useful in interpreting the NMR spetra of ...
Mitsuru Sano, Yuzo Yoshikawa, Hideo Yamatera   +2 more
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Variations of Nitrogen-15 Abundance in Soils

Science, 1964
A survey of the isotopic composition of soil nitrogen has shown that there is variation in the abundance of nitrogen-15 in soils and in different forms of soil nitrogen. The variation detected is small, but it cannot be attributed to analytical errors and should be considered in studies of nitrogen transformation in soils when nitrogen-15 is used as a ...
H H, Cheng, J M, Bremner, A P, Edwards
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Nitrogen‐15‐Depleted versus Nitrogen‐15‐Enriched Ammonium Sulfate as Tracers in Nitrogen Uptake Studies

Soil Science Society of America Journal, 1974
Abstract Fertilizer particles were prepared from ammonium sulfate with a lower (0.031) than natural (0.366) atom percentage of 15 N. The 15 N‐depleted material was compared with ammonium sulfate of a comparable level of
A. P. Edwards, R. D. Hauck
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Nitrogen-15 nuclear magnetic resonance spectroscopy. Nitrogen-15 chemical shifts determined from natural-abundance spectra

The Journal of Physical Chemistry, 1974
A number of ^(15)N chemical shifts, determined at the natural-abundance level of the isotope, are reported for some secondary alkylamines, amides, ureas, urethanes, heterocycles, and miscellaneous compounds. Substituent chemical-shift parameters have been derived for secondary-alkylamine ^(15)N chemical shifts.
Warren, John P., Roberts, John D.
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