bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of 1,4‐addition of grignard reagents to α,β‐unsaturated acid derivatives. III—configuration studies of α,β‐diaryl‐α,β‐dialkylpropionitriles
Authors: Wawzonek Stanley , Smolin Edwin M. , Durham Judith E. 
Published: May 2005

AbstractThe configuration of twenty‐four different α,β‐diaryl‐α,β‐dialkylpropionitriles has been determined using nuclear magnetic resonance spectra. The erythro form showed greater deshielding of the methine hydrogen and alkyl groups in its spectra than the corresponding threo isomer. The former, however, showed less deshielding of the aryl groups than the threo isomer. Infrared spectra were not suitable for assignments of configuration.
NMR spectra of molecules oriented in a lyotropic mesophase. III—The Spectrum of γ‐Hydroxypyridine
Authors: Khetrapal C. L. , Kunwar A. C. , Patankar A. V. 
Published: May 2005

AbstractAnalysis of the 1H NMR spectrum of γ‐hydroxypyridine dissolved in the lyotropic mesophase formed by a 14 : 1 : 1 : 20 mixture (by weight) of sodium dodecyl sulphate, decanol, sodium sulphate and D2O provides all the spectral parameters with reasonable precision. The chemical shift, the indirect and the direct proton–proton coupling constants are derived. The direct dipolar couplings thus determined are utilised to obtain the relative interproton distances. Information about the molecular orientation and the solvent solute interactions is deduced.
19F‐und 1H‐NMR‐spektroskopische Untersuchungen an Hexafluoraceton‐halbacetalen von Pyrimidin‐nucleosiden
Authors: Regel Walter , Stengele Eberhard 
Published: May 2005

AbstractDie Umsetzung der OH‐Gruppen von Pyrimidin‐nucleosiden mit Hexafluoraceton führt quantitativ zu Halbacetalen, deren 19F‐NMR‐Spektren eine eindeutige Charakterisierung erlauben und z.B. Aussagen über den selektiven Einbau von Schutzgruppen ermöglichen. Die gegenüber den Ausgangs‐verbindungen verbesserte Löslichkeit der Halbacetale in vielen organischen Lösungsmitteln erweist sich auch für die Protonen‐resonanzspektroskopie als wesentlicher Vorteil.
The effect of the structure of substituted phenylphosphonic difluorides on their 19F and 31P NMR spectral parameters
Authors: Szafraniec Linda L. 
Published: May 2005

AbstractThe 19F and 31P NMR spectral parameters of a series of meta and para substituted phenylphosphonic difluorides were found to be linearly related to the substituent parameters: the phosphorus chemical shifts correlated with Hammett's σ constant, the fluorine chemical shifts with Taft's σR parameter and the phosphorus–fluorine coupling constants with σ+.
The structure of 1,6,6aλ4‐trithiapentalene and substituted 1,6,6aλ4‐trithiapentalenes studied by means of NMR spectroscopy
Authors: Pedersen Carl Th. , Schaumburg Kjeld 
Published: May 2005

Abstract13C NMR spectra of unsubstituted 1,6,6aλ4‐trithiapentalene and a series of methyl and phenyl substituted 1,6,6aλ4‐trithiapentalenes have been recorded. The spectra have been assigned by comparison with 1H NMR data based on coupling constants from undecoupled spectra. From the chemical shift of C‐3a it is concluded that the double bond character of the C‐3a—S‐6a is low. The relaxation times for C‐2 and C‐3 only show small differences; this seems not to be in favour of a fast interconversion between two thiocarbonyl forms. The NMR data obtained seem thus to be in accordance with a bicyclic naphthalene‐like structure with ten delocalised π‐electrons.
1,2‐oxazine chemistry. V—vicinal, allylic and homoallylic coupling constants in the 3,6‐dihydro‐1,2‐oxazine ring
Authors: Riddell F. G. , Labaziewicz H. 
Published: May 2005

AbstractThe 1H NMR spectra of thirteen dihydro‐1,2‐oxazine derivatives are reported. Spin decoupling allows analysis of the spectra, features of which include homoallylic couplings of +2 to +2·5 Hz, allylic couplings of −1·5 to −1·7 Hz and vicinal couplings across sp2 to sp3 carbon–carbon bonds of +2·9 to +3·7 Hz.
Etude structurale de la bipyrimidine par RMN en phase nématique
Authors: Courtieu J. , Gounelle Y. , Duret C. , Gonord P. , Kan S. K. 
Published: May 2005

AbstractLe spectre de RMN obtenu à 240 MHz pour la bipyrimidine orientée dans un solvant nématique p‐métoxybenzylidène p‐n‐butyl aniline est analysé. La distance entre les hydrogènes en position para est déterminée. La barrière de potentiel s'opposant à la libre rotation autour de la liaison centrale CC est étudiée. Un excellent accord est obtenu entre spectre calculé et spectre expérimental lorsqu'on utilise une fonction potentielle V(ϕ) = 1/2 ΣNVn (1 ‐ cosn ϕ) avec V1 = V2 = V3 = 0 cal mol−1 et V4 = 500 cal mol−1.
Nitrogen‐15 magnetic resonance spectroscopy XVI—natural‐abundance spectra of aromatic amines
Authors: Lichter Robert L. , Roberts John D. 
Published: May 2005

AbstractThe 15N chemical shifts of aniline, the toluidines, xylidines, and several halogen and oxygen substituted anilines have been measured at the natural abundance level of 15N. Substituent parameters obtained by multiple regression analysis show that the methyl group induces comparable upfield shifts at the ortho and para positions (2·37 and 2·55 ppm/methyl, respectively) and a small (0·77 ppm/methyl) upfield shift at the meta position. The chemical shifts correlate reasonably well with 19F shifts of similarly substituted fluorobenzenes, with C‐1 of the anilines themselves and with Hammett sigma values. While the shifts of C‐methyl substituted anilines do not correlate with the methyl resonances of corresponding polymethylbenzenes, those of the halo‐ and alkoxyanilines show a reasonable parallelism with corresponding 13C‐methyl shifts. The results are interpreted in terms of possible modes of transmission of electron density in an alternating and additive manner through the sigma framework.
The 1H NMR spectra of some norbornene derivatives, a LIS study
Authors: Abraham Raymond J. , Coppell Steven M. , Ramage Robert 
Published: May 2005

AbstractThe 1H NMR spectra of 2‐exo‐hydroxymethyl‐3‐endo‐methylnorbornene and the corresponding 2‐endo‐3‐exo isomer have been completely assigned with the aid of lanthanide reagents. This enabled a full analysis of the unusual spectrum of 2‐exo‐hydroxy‐methyl‐3‐endo‐methylnorbornene to be undertaken, confirming the proposed structure. The ΔEu values for 2‐exo‐hydroxymethyl‐3‐endo‐methylnorbornene and the 2‐endo‐3‐exo‐isomer have been used to test the effect of rotational averaging on the calculated pseudo contact shifts. Good agreement is obtained for a dynamic model in which the Eu atom exchanges between two sites on the oxygen atom of the OH bond, and in which the rotational equilibrium about the CHCH2OH bond is explicitly considered.
ESR spectrum of the radical anion of bicyclo[3.2.2]nona‐3,6,8‐triene‐2‐one
Authors: Gerson F. , Moshuk G. , Wydler Ch. , Goldstein M. J. 
Published: May 2005

AbstractThe radical anion of bicyclo[3.2.2]nona‐3,6,8‐triene‐2‐one has been characterised by ESR spectroscopy.
Complexation du trichlorure d'aluminium par la triméthylphosphine et la diméthylphénylphosphine: Etude RMN
Authors: Laussac J.‐P. , Laurent J.‐P. , Commenges G. 
Published: May 2005

AbstractLes résultats de l'étude par résonance magnétique nucléaire des systèmes R3P/AlCl3 [avec R3 = (CH3)3 et (CH3)2 (C6H5)] ne peuvent ětre interprétés qu'en admettant l'existence, en solution et à 306 K, d'échanges rapides intéressant les complexes R3PAlCl3 et (R3P)2AlCl3 ainsi que la phosphine libre. Des expériences à basse température (173 K) confirment cette hypothèse et établissent définitivement l'existence des composés 2/1.
Etude par RMN d'une inversion de cycle de quelques benzodiazépinones
Authors: Sarrazin M. , Bourdeaux‐Pontier M. , Briand C. , Vincent E.‐J. 
Published: May 2005

AbstractLes modifications, en fonction de la température, des spectres RMN de cinq benzodiazépinones permettent de mettre en évidence un équilibre entre deux formes pseudo‐bateaux du cycle à sept liaisons. Les auteurs calculent les paramétres d'activation et la constante de vitesse d'inversion et discutent le rǒle des substituants.
tert‐Butyl 7‐cycloheptatrienylperacetate: The proton NMR spectrum and conformational analysis
Authors: Jurch G. R. , Johnston M. D. 
Published: May 2005

AbstractThe proton magnetic resonance spectrum of tert‐butyl 7‐cycloheptatrienylperacetate has been analyzed with the aid of the lanthanide shift reagents, Eu(fod)3 Yb(fod)3. Observation of the lanthanide‐induced shifts showed, in conjunction with variable temperature studies establishing the conformational purity of the cycloheptatrienyl ring, that the peracetate substituent has a definite equatorial preference.
13C NMR study of the enol forms of β‐diketones
Authors: Shapet'ko N. N. , Berestova S. S. , Lukovkin G. M. , Bogachev Yu. S. 
Published: May 2005

AbstractCarbon‐13 NMR spectra of a series of β‐diketones in the enol form with various β‐substituents have been studied. An additive influence of the β‐substituents on the chemical shifts of the carbon atoms in the hydrogen bonded chelate ring has been found. It is shown that the α‐ and β‐carbon chemical shifts can be calculated by means of a set of increments for arbitrary combinations of the X and Y substituents. Analysis of the experimental data enables the conclusions to be drawn that enol–enolic tautomerism with different populations of the forms (A) and (B) is absent in β‐diketones and that the carbon chemical shift changes are caused by electron density redistribution in the hydrogen bonded chelate ring (C).
Lanthanide‐induced shifts of diastereotopic groups
Authors: Bell Harold M. 
Published: May 2005

AbstractThe chemical shift differences of diastereotopic protons in aliphatic acyclic alcohols, mostly of the type RCH2CR′R″(CH2)nOH, have been investigated. Fairly small amounts of Eu(dpm)3 cause the spectra of these materials to simplify dramatically; indeed, even diastereotopic protons rather far removed form the hydroxyl group give discrete signals in the presence of the shift reagent. Large shift differences were realized in the γ‐protons (n = 1) and the δ‐protons (n = 2), particularly if R is bulky and R' and R″ have different steric requirements. Semi‐quantitative conformational preferences can be determined from the data obtained.
An investigation of contributions to carbon‐13 spin‐lattice relaxtion in amino acids and peptide hormones
Authors: Cutnell J. D. , Glasel Jay A. , Hruby V. J. 
Published: May 2005

AbstractCarbon‐13 spin‐lattice relaxation times have been measured in glycine and the tripeptide pro‐leu‐gly‐NH2. These times are compared with those measured in the same compounds where the glycine α‐carbon has been deuterated. In this manner evidence is obtained which indicates that mechanisms other than dipolar interactions with covalently bonded protons may contribute to carbon‐13 spin‐lattice relaxation. The effect of these additional mechanisms is found to be non‐negligible for the carbonyl carbon of glycine and the glycine α‐carbon of the tripeptide. The implication of these findings for deducing motional information from carbon‐13 relaxation measurements is briefly discussed.
Beziehungen zwischen chemischer Verschiebung (19F und 13C) und Ladungsdichte: III
Authors: Sterk Heinz , Fabian Walter 
Published: May 2005

AbstractDer diamagnetische und paramagnetische Term der chemischen Verschiebung wird durch semiempirische CNDO/II Ladungsdichte‐und Bindungsordnungswerte ausgedrückt. Es wird untersucht ob ein linear funktionaler Zusammenhang zwischen den berechneten Termen und der chemischen Verschiebung von 19F‐ und 13C‐Atomen besteht. In Form einer linearen Regression werden eine Reihe unterschiedlicher Ansätze–unter Berücksichtigung von s̀dia sowie s̀dia + s̀para—untersucht. Es zeigt sich, daß die Beziehung δA = a + bqA + cQAB + dqAπQAB den kleinsten mittleren Fehler aufweist.
Conformational analysis. XIII—A 300 MHz 1H NMR study of 2‐methyl‐, 2‐phenyl‐, 2‐(2‐chlorophenyl)‐and 2‐(4‐chlorophenyl)‐oxetanes
Authors: Pihlaja Kalevi , Jokisaari Jukka , Olavi P. , Virtanen I. , Ruotsalainen Heikki , Anteunis Marc 
Published: May 2005

AbstractThe 300 MHz spectra of 2‐methyl‐, 2‐phenyl‐, 2‐(2‐chlorophenyl)‐ and 2‐(4‐chlorophenyl)‐oxetanes were recorded in CCl4 and C6D6. The chemical shifts and the proton‐proton coupling constants were solved through iterative calculations. The results were discussed in the light of structural factors and theoretical calculations. The average angle of pucker for the oxetane ring was estimated at c. 5°, in fair agreement with the value of 3·3° derived from a microwave study.
Hétérocycles contenant du phosphore. XXIV—Etude par RMN du proton de l'oxo‐2 phénoxy‐2 diphényl‐6,6 oxazaphosphorinane‐1,3,2 et de l'oxo‐2 phénoxy‐2 méthyl‐4 oxadiazaphosphorinane‐1,3,4,2
Authors: Arshinova Rausa , Kraemer Raymond , Majoral Jean‐Pierre , Navech Jacques 
Published: May 2005

AbstractDeux hétérocycles phosphorés sont étudiés au moyen de la RMN du proton et de l'infrarouge. La conformation du cycle est précisée et l'angle de torsion de la liaison C‐5—C‐6 est calculé pour l'un d'eux.
Verification of the correlation between geometric parameters of molecules and the parameters of their 1H NMR spectra
Authors: Vorontsova L. G. , Bochkov A. F. 
Published: May 2005

AbstractThe dihedral and bond direction angles between all pairs of vicinal protons of the arabinofuranose residue were calculated from the coordinatees of the hydrogen atoms found by an X‐ray study of 3‐O‐acetyl‐β‐L‐arabinofuranose 1,2,5‐orthobenzoate. The values found were compared with those calculated with the help of correlation equations previously proposed by Karplus and recently by the authors, linking the values of those angles with the spin‐spin coupling constants of vicinal protons [3J(H,H′)]. It has been found that the best agreement between the angles found crystallographically and calculated from the 1H NMR data can be achieved using the equation which includes bond direction angles and the sum of the chemical shifts of the protons involved.
Solvent effects of pyridine on the NMR spectra of carboxylic acids. I—study of the acrylic, trans‐crotonic and 3‐butenoic acids
Authors: Paasivirta Jaakko , Kolehmainen Erkki 
Published: May 2005

AbstractProton magnetic resonance spectral parameters of acrylic, trans‐crotonic and 3‐butenoic acids, their methyl esters and the corresponding alcohols (COOH substituted by CH2OH) have been measured for 5% (w/v) solutions in carbon tetrachloride and in pyridine‐d5 at 33·5 °C. The total solvent effect of pyridine on the shifts of the skeleton protons of the acid was found to consist of three different effects independently measured from the reference samples.
Carbon‐13 chemical shifts and 13C15N coupling constants of 3,4‐dihydroisoquinoline‐15N, its 15N‐oxide and their conjugate acids
Authors: Christl Manfred 
Published: May 2005

AbstractOn protonation of 3,4‐dihydroisoquinoline‐15N 1J(13C—1, 15N) is increased by a factor of five and 1J(13C—3, 15N) changes its sign, while on protonation of 3,4‐dihydroisoquinoline‐15N‐oxide the coupling constants, including the relatively large 1J(13C—1, 15N), remain practically constant, although significant alterations of the 13C chemical shifts take place.
Carbon‐13 NMR Spectra of some aryl substituted ferrocenes
Authors: Gronowitz S. , Johnson I. , Maholanyiova A. , Toma S. , Solcániová E. 
Published: May 2005

AbstractThe carbon‐13 spectra of some para and meta substituted phenylferrocenes have been analysed. The substituent‐caused shifts are discussed and compared with similarly substituted biphenyls. Correlations with Hammett parameters and with the reactivity parameters of Swain and Lupton have been attempted.
NMR study of organosilicon compounds. III—Silicon‐29, nitrogen‐14, carbon‐13 and proton NMR spectra of silylakylamines
Authors: Schraml J. , Nguyen‐Duc‐Chuy  , Chvalovský V. , Mägi M. , Lippmaa E. 
Published: May 2005

Abstract29Si, 14N 13C and 1H NMR data are presented for a series of homologous (methylethoxysilyl)alkylamines of the type (CH3)3−n(C2H5O)nSi(CH2)mNH2(n=o to 3; m = 1 to 4). The measured 13C and 1H chemical shifts correlate with the total net charges QA on the corressponding atoms, estimated by the Del Re method. 14N and 29Si chemical shifts which do not show simple linear relationships to the charges are found to correlate with the relative basicities of the compounds. The influence of the remote substituent (NH2 and others) on the 29Si chemical shifts is shown to depend on the number and nature of substituents directly on the silicon atom. Argyments for d‐orbital participation in the SiO bounds are given. The chemical shifts of 29Si, 14N and 13C nuclei are not consistent with the fromation of intramolecular ‘long bonds’ between the solicon and nitrogen atoms in aliphatic silymethylamines.
1H and 13C NMR study of α‐acetylenic PIII and PIV derivatives. Signs and magnitudes of J(PC) and J(PH)
Authors: Lequan R.‐M. , Pouet M.‐J. , Simonnin M.‐P. 
Published: May 2005

AbstractAll J(PH) and J(PC) values, including signs, have been obtained in acetylenic and propynylic phosphorus derivatives, R2P(X)CCH and R2P(X)CCCH3 (X  oxygen, lone pair and R  C6H5, N(CH3)2, OC2H5, N(C6H5)2, Cl) from 1H and 13C NMR spectra. In PIV derivatives the following signs are obtained: 1J(PC)+, 2J(PC)+, 3J(PC)+, 3J(PH)+, 4J(PH). Linear relations are observed between 1J(PC), 2J(PC) and 3J(PC) versus 3J(PH), indicating that these coupling constants are mainly dependent on the Fermi contact term, though the other terms of the Ramsey theory do not seem to be negligible for 1J(PC) and 2J(PC).In PIII derivatives these signs are: 1J(PC)‐ and +, 2J(PC)+, 3J(PC)‐, 3J(PH)‐, 4J(PH)+. Only 3J(PC) and 3J(PH) reflect a small contribution of the Fermi contact term while in 1J(PC) and 2J(PC) this contribution seems to be negligible relative to the orbital and/or spin dipolar coupling mechanisms.
Carbon‐13 NMR study of enamines and enamino ketones. A direct observation of the conformation of the 2‐methylcyclohexanone enamine tautomers
Authors: Tourwé D. , Van Binst G. , De Graaf S. A. G. , Pandit U. K. 
Published: May 2005

AbstractThe carbon‐13 spectra of a series of cyclohexanone, cyclopentanone and 2‐methylcyclohexanone enamines are reported. The influence of the amino component was studied in a series of enamino ketones. The spectra reflect the amount of p‐π overlap in the molecules and their conformation. Differences between 5‐and 6‐membered carbonyl components are evaluated.
Equilibre conformationnel du fluoro‐1 chloro‐2 cyclohexane cis
Authors: Baillif Patrick , Martin Jacques André 
Published: May 2005

AbstractL'équilibre conformational et la cinétique de l'inversion du cycle sont étudiés essentiellement à partir de la forma de raie du fluor. Une nouvelle méthode de calcul des grandeurs thermodynamiques d'activation est présentée.
The 1H NMR spectra of quinoline, quinoline N‐oxide, the quinolinium ion and of their monomethyl derivatives
Authors: Barbieri Giorgio , Benassi Rois , Lazzeretti Paolo , Schenetti Luisa , Taddei Ferdinando 
Published: May 2005

Abstract1H chemical shifts of quinoline, quinoline N‐oxide and the quinolinium ion were obtained by complete analysis of their NMR spectra and interpreted critically in an attempt to quantify the possible different effects acting on the shielding constant of protons in these systems. Semi‐empirical SCF calculations of electron charge densities and ring current contributions were also performed. It was found that the same effects that act on the shielding of protons directly bonded to the heterocyclic system also act, in an attenuated form, on the proton chemical shift of methyl groups in monomethyl derivatives. Vicinal coupling constants were rationalised in terms of π‐electron bond order and electro‐negativity of neighbouring atoms.
Effect of methyl substituents on the NMR spectra of aromatic protons of some nitrobenzene derivatives
Authors: Beltrame Paolo , Carniti Paolo , Lai Adolfo , Viglino Paolo 
Published: May 2005

AbstractProton NMR spectra were recorded and analysed for 1‐bromo‐4‐nitrobenzene, 2‐bromo‐5‐nitroluene, 3‐bromo‐6‐nitrotoluene and 2‐bromo‐5‐nitro‐p‐xylene, as well as for the corresponding compounds having p‐CH3C6H4S in place of Br. Chemical shifts and coupling constants generally agree with expected values; however, a deshielding effect of the methyl group on aromatic protons was observed in one case.
31P‐NMR‐Daten heterocyclischer phosphine. Diastereomerenzuordnung an 1,3‐Oxa‐, 1,3‐Aza‐ und 1,3‐thiaphospholanen
Authors: Zschunke A. , Meyer H. , Issleib K. 
Published: May 2005

AbstractDie Diastereomeren von 16 1,3 Oxa‐, 1,3‐Aza‐und 1,3‐Thiophospholanen wurden mit Hilfe der Kopplungs‐konstanten 2J(PCH) und 3J(PCCH3), der Signalbreite der 31P‐Signale und der 1H‐chemischen Verschiebungen der CH3‐Gruppen zugeordnet. Es wird gezeigt, daß auch die 31P‐chemischen Verschiebungen eine Bestimmung der relativen Konfiguration dieser Verbindungen gestatten.
Proton magnetic resonance studies of compounds with bridgehead nitrogen: XXVIII—Stereochemical studies with perhydropyrido[1,2‐c] [1,6,3]dioxazocines and 2‐alkylperhydropyrido[1,2‐c] [1,3,6]oxdiazocines
Authors: Crabb Trevor A. , Jackson Graham C. 
Published: May 2005

AbstractA series of perhydropyrido[1,2‐c][1,6,3]dioxazocines and 2‐alkylperhydropyrido[1,2‐c][1,3,6]oxdiazocines have been prepared. 6‐p‐Nitrophenyl‐3,4‐dimethylperhydropyrido[1,2‐c][1,6,3]‐dioxazodioxazocine is shown to adopt the cis fused ring conformation in solution with the nitrogen lone pair axial with respect to the piperidine ring. The 2‐alkylperhydropyrido[1,2‐c][1,3,6]oxdiazocines adopt a similar cis fused ring conformation and with increasing steric requirement of the 2‐alkyl substituent the 8‐membered ring increasingly favours the chair‐chair conformation, rather than the chair–boat conformation favoured by the 2‐methyl substituted compound.
Coupling constants in N‐substituted pyridines and their relation with electronegativity
Authors: Katritzky Alan R. , Kinns Michael , Lunt Edward 
Published: May 2005

AbstractThe coupling constants obtained from the complete spectral analysis of series of 1‐ and 3‐substituted pyridine N‐imides are related linearly to the electronegativities of the substituent atoms. The main conclusions of the papers by Cox, Castellano and Sun, and Castellano and Kostelnik are substantiated. The inductive effects of the first atoms of the substituents largely determine the coupling between protons in the ring system; delocalisation of π‐electrons in the ring produces a much smaller effect.
Quantitative analysis by nuclear magnetic resonance with fourier transformation: I—Proton case
Authors: Thiault B. , Mersseman M. 
Published: May 2005

AbstractFor quantitative analysis by NMR spectroscopy with Fourier transform, the usual experimental conditions have to be partly modified. Careful regulation of the delays between the different phases of the process is particularly important. The filters of the spectrometer and the calculations on the free induction decay are important causes of error. Precise results are given.
Etude par Résonance Magnétique Nucléaire du 13C des chlorhydrates de‐N‐(phényl‐1 cyclohexyl) piperidines.
Authors: Geneste P. , Kamenka J. M. 
Published: May 2005

AbstractL'attribution des signaux de RMN du 13C de la N‐(phényl‐1 cyclohexyl) pipéridine et de quelques dérivés 4‐substitués, sous forme de chlorhydrates dans H2O et CDCl3, a permis une étude conformationnelle. Celle‐ci confirme la plus grande stabilité des composés dont le groupe pipéridinium est équatorial. Certaines particularités dans les glissements chimiques observés paraissent attribuables à des déformations du système cyclohexanique, étroitement liées au phénomène de solvatation.
A proton magnetic resonance study of isomeric alkylidencyanoesters
Authors: Giralt Ernest , López Francisco , Alvarez Mercedes 
Published: May 2005

AbstractEthyl 2‐cyano‐3‐methyl‐4‐phenyl‐2‐pentenoate was obtained as a mixture of two geometric isomers. An aromatic solvent induced shift experiment and calculations of the difference in the chemical shifts of methyl protons linked to the double bond lead to the assignation of the geometry of both isomers.