ISSN:0030-4921    

DOI:10.1002/mrc.1270081215

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractThe13C n.m.r. spectra of some 2‐heteroadamantanes and 1‐substituted 2‐heteroadamantanes are reported. The influences of the heteroatoms in the adamantane framework, and those of the substituents attached to it, on the13C chemical shifts of the adamantane carbons are investigated and compared with related compounds such as the corresponding heterocyclohexane derivatives and 2‐mono‐ and 2,2‐disubstituted adamantanes. The nonadditivity of the substituent effects for 1‐substituted 2‐heteroadamantanes, especially for the geminally substituted carbons, is substantially confirmed. In addition, the influences of a missing CH2group and of NCH3carbons upon the13C chemical shifts of the carbons in the adamantane syste

ISSN:0030-4921    

DOI:10.1002/mrc.1270081202

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractLes structures d'imines et d'oxazirannes dérivés de la méthyl‐2 et de la diméthyl‐2,6 cyclohexanone ont été déterminées par RMN1H. Nous avons pu montrer que pour tous les oxazirannes étudiés, la conformation préférentielle correspond à une position équat

ISSN:0030-4921    

DOI:10.1002/mrc.1270081203

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

Abstract13C n.m.r. spectral data of pteridine and nineteen of its derivatives (containing one or more chloro, methylthio, methyl,t‐butyl or phenyl substituents) are reported. The13C n.m.r. spectrum of the title compound has been assigned conclusively.13C n.m.r. substituent effects are shown to be very useful in discerning between 6‐ and 7‐substituted pteridines. Additionally, the13C n.m.r. spectra of several covalent amination products, i.e. the 3,4‐dihydro‐4‐ amino‐ and the 5,6,7,8‐tetrahydro‐6,7‐diaminopteridine derivatives, formed by dissolving the appropriate pteridine in liquid ammonia, have been recorded. The13C n.m.r. spectra of the corresponding covalent hydrate

ISSN:0030-4921    

DOI:10.1002/mrc.1270081204

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractL'étude des déplacements chimiques de13C des dérivés monosubstitués du cyclopropane (C3H5X, X = CH3, Br et CCH) permet la détermination des paramètres directs d'additivité qui ne dépendent que de la nature du substituant. Dans le cas de substitutions multiples, à ces effets directs se superposent des effets complémentaires dus à des interactions croisées entre les substituants. L'étude systématique des dérivés polysubstitués par des atomes de brome et des groupements méthyle et ethynyle, met en évidence ces différentes contributions, et nous permet de proposer pour la plupart des cas une interprétation simple. Ces interactions font appel, soit à des transferts électroniques, soit à des interactions stériques, symétriques ou dissymétriques, entre les différents substituants ainsi que le montre la comparaison entre valeurs théoriques et mesures expérim

ISSN:0030-4921    

DOI:10.1002/mrc.1270081205

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractThe carbon‐13 n.m.r. spectra of three isomers of 4b, 5,6,7,8,8a,10,11,16,16b‐decahydrodibenz[f,h]indolo[2,3‐a]quinolizine were interpreted with the aid of the 1,2,3,4,4a,5,6,10b‐octahydro‐6‐phenylphenanthridines and the 2‐phenylcylohexylamines. The configuration and the conformation of these compounds can be determined from the chemical

ISSN:0030-4921    

DOI:10.1002/mrc.1270081206

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractDie ESR‐Spektren von Neutralradikalen in Lösung, erzeugt durch elektrolytische Reduktion einer Reihe dinuclearer Polymethinoxonole, werden interpretiert. Auf Grund der Werte der ESR‐Kopplungskonstanten, von1H‐NMR‐Messungen und HMO‐Rechnungen werden Konformation, π‐Elektronendichte‐verteilung und CC‐Bindungslängen bei diesen

ISSN:0030-4921    

DOI:10.1002/mrc.1270081207

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractAn analysis of the19F n.m.r. spectra of heptafluoroisoquinoline and hexafluoro‐1‐methoxyisoquinoline is presented. As in heptafluoroquinoline, the inter‐ring FF coupling constants alternate in sign and magnitude and are positive over an odd number of bonds. They correlate with SCFMO carbon–carbon polarizabilities and this infers that the long‐range coupling mechanism is dominated by the contribution from the π‐e

ISSN:0030-4921    

DOI:10.1002/mrc.1270081208

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractMagnitudes and signs of13C13C coupling constants in compounds of the type Ph13CR1R213CR1R2Ph have been determined and the results are discussed in a broader context. Two types of coupling constants,J(C‐i, C‐α) andJ(C‐i, C‐β), between aromatic carbon atoms and the benzylic carbons, probably with different coupling mechanisms, are considered. Whereas2J(C‐2, C‐α) are always found positive,2J(C‐1, C‐β) in the present compounds are found to be negative or about zero.3J(C‐3, C‐α) has the same sign as2J(C‐2, C‐α). A4Jand

ISSN:0030-4921    

DOI:10.1002/mrc.1270081209

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY

摘要:

AbstractThe capabilities of a novel computer program for the ‘automatic analysis of n.m.r. spectra’ [J. Magn. Reson.19, 67 (1975)] are demonstrated in the analysis of the experimental spectra of oriented 2,4‐dichlorobenzaldehyde and 2‐chlorobenzaldehyde. In both cases solutions are found by starting from parameters which do not allow a line assignment. The fitting procedure is described in detail and the conclusion is reached that the program is a typical search program which is able to find, fully automatically, parameters which are unknown in principle. However, for reasons of efficiency, a certain amount of interaction between the computer and the spectroscopist is desirable. The structural results indicate that in both molecules, which are assumed to be planar, theO‐trans‐configuration vastly predominates and that the benzene rings are considerabl

ISSN:0030-4921    

DOI:10.1002/mrc.1270081210

出版商:John Wiley&Sons Limited    

年代:1976

数据来源: WILEY