Effects of conjugation by means of NMR spectroscopy Communication 23.1H and13C NMR spectra of cis- and trans-isomers of ?-phenylalkylthioethylenes

1984 ◽  
Vol 33 (9) ◽  
pp. 1821-1825
Author(s):  
V. M. Bzhezovskii ◽  
O. A. Tarasova ◽  
B. A. Trofimov ◽  
V. V. Shcherbakov ◽  
G. A. Kalabin ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Morpholines: stereochemistry and preferred steric course of quaternization

1976 ◽  
Vol 54 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Alan J. Jones ◽  
C. P. Beeman ◽  
M. U. Hasan ◽  
A. F. Casy ◽  
M. M. A. Hassan
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Nmr Spectra ◽  
Deuterium Nmr ◽  
Free Energies ◽  
Trans Isomers ◽  
Methyl Substitution ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

The 13C magnetic resonance spectra of a series of methyl and phenyl substituted morpholines, their hydrochlorides, and methiodides have been determined. The effects of methyl substitution adjacent to oxygen and nitrogen are reasonably equivalent and substituent induced chemical shift parameters derived for the series show favorable agreement with those previously observed in both alicyclic and heterocyclic systems. Results for the cis and trans isomers of phendimetrazine (3,4-dimethyl-2-phenylmorpholine), confirm the preferred chair conformations and configurations cis-3-CH3, cis-2-phenyl (cis) and trans-3-CH3, cis-2-phenyl (trans) for these isomers. The preferred course of quaternization of nitrogen in these systems was determined as axial, using deuteriomethyliodide as a label. This 13C–2H technique relies on the observation of the γ-syn-axial effect and is clearly unambiguous and superior to other methods used in evaluating this mechanism. Product ratios and consequently free energies of this reaction were measured from proton and deuterium nmr spectra.

Synthese von Silicium-Phosphor-Ringen - Struktur eines cis-2.2.4.4-Tetrakis(silylamino)-1.3-diphospha-2.4-disilacyclobutans / Synthesis of Silicon-Phosphorus-Rings - Structure of a cis-2,2,4,4-Tetrakis(silylamino)-1,3-diphospha-2,4-disilacyclobutane

1983 ◽  
Vol 38 (12) ◽  
pp. 1557-1562 ◽  
Author(s):  
Uwe Klingebiel ◽  
Norbert Vater ◽  
William Clegg ◽  
Martin Haase ◽  
George M. Sheldrick
Keyword(s):  
Crystal Structure ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Molar Ratio ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
By Products ◽  
Cis Isomer

Fluorosilylphosphanes of the type R2SiFPHR′ (R = CHMe2, CMe3, NMeSiMe3; R′ = H, C6H5; 1-4) are obtained in the reaction of difluorosilanes with lithiated phosphanes in a molar ratio 1:1. Diphosphasilanes (5, 6) and a difluorosilylphosphane (7) are isolated as by-products. 1-4 react with n-C4H9Li to give cyclic silylphosphanes, LiF, and C4H10 (8-11). Dilithiated 5 reacts with F2PN(CMe3)SiMe3 to form of a four-membered SiP3-ring 12. The 31P NMR spectra of 9 and 11 show signal coalescence for the cis-and trans-isomers at room temperature. The crystal structure of the cis-isomer of 11 has been determined. The substituted ring 13 is prepared in the reaction of lithiated 9 and Me2SiF2

scholarly journals Notizen: High-field (500 MHz) 1H NMR Spectra of Retinoic Acids and Arotinoids by Two-dimensional Chemical Shift Correlation (2D) Spectroscopy

1988 ◽  
Vol 43 (8) ◽  
pp. 1072-1074 ◽  
Author(s):  
Bruno Perly ◽  
Giuseppe C. Pappalardo ◽  
Michael Klaus ◽  
Enzo Montoneri
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Chair Conformation ◽  
Two Dimensional ◽  
Trans Isomers ◽  
Chemical Shift Correlation ◽  
H Nmr ◽  
Retinoic Acids ◽  
Cis And Trans Isomers ◽  
Cis And Trans

AbstractThe 1H NMR spectra (in DMSO solution at 300 K) of retinoic acids (cis- and trans-isomers) and new arotinoids were run at 500 MHz and assigned by using homo- and heteronuclear two-dimensional (2D) chemical shift correlation experiments. Spectral analysis was indicating, on the basis of 7 values, that the ring C(l)-C(2)-C(3)-C(4)-C(5)-C(6) adopts, in all compounds, a chair conformation.

Metallkomplexe der Phosphinsäuren, XVI [1]. cis-trans-Isomerie bei planaren Palladiumund Platinkomplexen [RR′ PS2]2M [2] / Metal Complexes of Phosphinic Acids, XVI [1]. cis-trans Isomers of Planar Palladium and Platinum Complexes [RR'PS2]2M [2]

1980 ◽  
Vol 35 (2) ◽  
pp. 239-241 ◽  
Author(s):  
Wilhelm Kuchen ◽  
Reinhard Uppenkamp
Keyword(s):  
Metal Complexes ◽  
Nmr Spectra ◽  
Platinum Complexes ◽  
Trans Isomers ◽  
H Nmr ◽  
Cis And Trans Isomers ◽  
Phosphinic Acids ◽  
Palladium And Platinum Complexes ◽  
Dithiophosphinic Acids ◽  
Cis And Trans

Unsymmetrically substituted dithiophosphinic acids RR'P(S)SH give planar metal chelates [RR'PS2]2M 1 [M = Pd(II), Pt(II)]. It can be shown by comparison of their 31P-{1H} NMR spectra with those of symmetrically substituted compounds [R2PS2]2M that in the synthesis of 1 equimolar mixtures of the cis and trans isomers are formed.

Cis- und trans-Isomere des 1.5-Dimethyl-3.6-diphenoxy-3.6-dithioxo-1.2.4.5-tetraza-3.6-diphosphacyclohexans (des 1.5-Dimethyl-3.6-diphenoxy-3.6-dithioxocyclodi(phosphadiazans)) / Cis- and trans-Isomers of 1,5-Dimethyl-3,6-diphenoxy-3,6-dithioxo-1,2,4,5-tetraza-3,6-diphosphacyclohexane (of 1,5-Dimethyl-3,6-diphenoxy-3,6-dithioxocyclodi(phosphadiazane))

1977 ◽  
Vol 32 (12) ◽  
pp. 1435-1438 ◽  
Author(s):  
Udo Engelhardt ◽  
Hans-Joachim Merrem
Keyword(s):  
Title Compound ◽  
Nmr Spectra ◽  
Trans Isomers ◽  
H Nmr ◽  
Cis And Trans Isomers ◽  
Cis And Trans

C6H5O-(S)P(N(CH3)-NH2)2 reacts with C6H5O(S)PCl2 to give the title compound. The cis- and trans-isomers of this product have been separated and are characterized by their IR, 1H NMR and 31P NMR spectra.

Azido(imidazole)bis(acetylacetonato)cobalt(III) Complexes — Facile trans ⇋ cis Interconversion in Solution

1985 ◽  
Vol 40 (4) ◽  
pp. 470-476 ◽  
Author(s):  
J. K. Das ◽  
K. C. Dash
Keyword(s):  
Nmr Spectra ◽  
Equilibrium Mixture ◽  
Biologically Active ◽  
Trans Isomers ◽  
Active Ligand ◽  
Azide Ion ◽  
Cis And Trans Isomers ◽  
Neutral Base ◽  
Cis And Trans ◽  
C Nmr

A number of mixed-ligand complexes of cobalt(III) containing coordinated azide ion, acetyl- acetonatc anion and the neutral base imidazole and, having the general formula [Co(acac)2(N3)(Im)] (Im = imidazole or its derivatives) have been synthesised by the reaction of K[trans-Co(acac)2(N3)2] with the biologically active ligand imidazole or its derivatives. IR and electronic spectra alongwith 1H and 13C NMR spectra have been employed to characterise the complexes and determine their geometry. In contrast to the stable trans-[Co(acac)2(NO2)(Im)] complexes, these azido complexes arc shown to undergo facile trans ⇋ cis interconversion in CHCl3 solution. The NMR spectra (1H and 13C) can be interpreted by assuming the presence of an equilibrium mixture of the cis- and trans-isomers in solution.

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