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1. |
Progress in nuclear quadrupole resonance investigations of halogen‐containing organic and organometallic compounds |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 665-687
M. G. Voronkov,
V. P. Feshin,
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摘要:
AbstractRecent nuclear quadrupole resonance (n.q.r.) investigations of halogen‐containing organic and organometallic compounds, covering the period between 1970–1976, are reviewed. Special attention is paid to n.q.r. studies of the stereochemistry of organic molecules with particular emphasis on the interactions of geminal atoms, and the application of Stark effects to the study of the coordination and hybridization of at
ISSN:0030-4921
DOI:10.1002/mrc.1270091202
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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2. |
Effets de Substituants en Série Diazolique et Diazinique‐1,3—Etude par Résonance Magnétique Nucléaire du Carbone‐13 |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 688-694
R. Faure,
E.‐J. Vincent,
G. Assef,
J. Kister,
J. Metzger,
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摘要:
AbstractNous avons enregistré les spectres de RMN du carbone‐13 de thiones et de thioethers, en série diazolique et diazinique‐1,3, diversement substitués sur les atomes d'azote par des groupements alkyles, ainsi que certaines des structures oxygénées homologues. Toutes les raies de résonance ont été attribuées. Dans le cas des dérivés thiocarbonylés, nous montrons que l'équilibre thiol ⇄ thione est déplacé vers la forme thione, mais que la RMN du carbone‐13 ne peut conduire qu'à une évaluation qualitative de la position de cet équilibre. L'analyse des effets de substituant montre que, contrairement aux composés oxygénés, le groupement isopropyle adopte dans les dérivés soufrés une conformation privilégiée par suite de l'encombrement stérique dǔ à l'atome de soufre. La substitution par un groupement tertiobutyle conduit à des valeurs des effets γ inattendus. Nous attribuons ce phénomène à des déformations de cycle ou à des variations des angles valentiels de l'azote porteur du substituant, provoquées par des interactions stériques entre le substituant et le cycle correspondant. Nous relions ces modifications à certaines modalités de la réactivité, et
ISSN:0030-4921
DOI:10.1002/mrc.1270091203
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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3. |
A rotational barrier about the isopropyl to aryl bond in highly substituted sulphines |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 695-698
Albert Tangerman,
Binne Zwanenburg,
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摘要:
AbstractThe rotational barriers in sulphines containing the substituents 2,6‐dimethyl‐3‐isopropyl‐4‐methoxyphenyl and 4,6‐dimethyl‐3‐isopropyl‐2‐methoxyphenyl are discussed. Particular attention is given to the occurrence of a barrier to rotation about the isopropyl to aryl bond. In both types of sulphines the isopropyl group is flanked by a methyl and a methoxy group. The isopropyl to aryl barrier could only be detected in the sulphines containing the second type of substituent where theo‐methoxy group experiences a buttressing effec
ISSN:0030-4921
DOI:10.1002/mrc.1270091204
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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4. |
Iterative least‐squares analysis of dynamic n.m.r. spectra. Hindered rotation of theN‐nitroso group inN‐nitroso‐N‐cyanomethylmethylamine |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 699-702
S. Szymański,
L. Stefaniak,
M. Witanowski,
A. Ejchart,
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摘要:
AbstractIterative analysis of dynamic n.m.r. (d.n.m.r.) spectra by the least‐squares method was applied to the entire proton spectrum ofN‐nitroso‐N‐cyanomethylmethylamine and, separately, to the CH3and CH2CN sub‐spectra. Resulting differences in the estimated rates of rotation of the NO group are discussed in terms of systematic errors which may be involved in determining spin exchange rates by d.n.m.r. methods. The most probable explanation is that quadrupolar broadening and then unresolved14N1H spin–spin splitting may appear on increasing the temperature. Estimated entropies of activation indicate that the methyl sub‐spectrum gives more r
ISSN:0030-4921
DOI:10.1002/mrc.1270091205
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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5. |
Étude des Phénomènes de Redistribution dans les Systèmes BR3/BT3avec T = –OCH3, –SCH3, –N(CH3)2 |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 703-707
Jean‐Pierre Costes,
Gérard Cros,
Jean‐Pierre Laurent,
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摘要:
AbstractL'étude des spectres de résonance nucléaire (1H,11B) de différents mélanges BR3/BT3/ avec T = OCH3, SCH3et N(CH3)2met en évidence l'existence d'équilibres de redistribution entre les espèces BRnT3–n(n= 0, 1, 2, 3). II apparaǐt que, d'une façon générale, les espèces mixtes (n= 1 et 2) sont plus favorisées que ne le laisserait prévoir un modèle de redistribution au hasard. Les facteurs d'ordre stérique et électronique susceptibles d'intervenir dans ces réac
ISSN:0030-4921
DOI:10.1002/mrc.1270091206
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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6. |
Three nuclei n.m.r. spectroscopy of dimethoate compounds. A large solvent effect on the31PSC1H vicinal coupling |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 708-711
Jaakko Paasivirta,
Jarmo Simanainen,
Raili Vesterinen,
Liisa Virkki,
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摘要:
AbstractProton, phosphorus and carbon magnetic resonance spectra of dimethoate, dimethoxon, des‐N‐methyldimethoate, ω‐hydroxydimethoate, trimethyldithiophosphate andO,O‐dimethyldithiophosphate in different solvents have been measured. Most of the n.m.r. parameters were characteristic of the structural environment of the corresponding nucleus and solvent‐independent. However, in the amide structures dimethoate, dimethoxon, des‐N‐methyldimethoate and ω‐hydroxydimethoate the31PSC1H vicinal coupling showed an unusually large solvent effect of a 2.3 to 6.5 Hz decrease when CDCI3was replaced
ISSN:0030-4921
DOI:10.1002/mrc.1270091207
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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7. |
Carbon‐13 n.m.r. studies: 68—diastereomeric nonequivalence and the characterization of some bisnorbornylpinacols |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 712-715
J. B. Stothers,
K. C. Teo,
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摘要:
AbstractThe sodium‐ammonia reduction of racemic norcamphor,exo‐3‐methylnorcamphor and 3,3‐dimethyl‐norcamphor (camphenilone) leads to substantial yields (60–90%) of the corresponding 2,2′‐bisnorbornyl‐2,2′‐diols as diastereomeric mixtures. A combination of their1H,13C and infrared spectra together with the results of periodic acid and lead tetraacetate oxidations permits stereochemical assignments f
ISSN:0030-4921
DOI:10.1002/mrc.1270091208
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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8. |
N.m.r. studies in the heterocyclic series: XVII—carbon‐13 spectra of indazole derivatives |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page 716-718
Philippe Bouchet,
Alain Fruchier,
Gérard Joncheray,
Jose Elguero,
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摘要:
AbstractThe13C chemical shifts of 17 indazole derivatives are discussed as a function of substituent effects and the N‐1—H or N‐2—H structure of indazole. The presence in solution of the N‐1—H tautomer i
ISSN:0030-4921
DOI:10.1002/mrc.1270091209
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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9. |
Masthead |
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Organic Magnetic Resonance,
Volume 9,
Issue 12,
1977,
Page -
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ISSN:0030-4921
DOI:10.1002/mrc.1270091201
出版商:John Wiley&Sons Limited
年代:1977
数据来源: WILEY
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