scholarly journals NMR analysis of 2-(2’,3’-dihydro-1’H-inden-1’-yl)-1H-indene

2001 ◽  
Vol 66 (11-12) ◽  
pp. 753-763 ◽  
Author(s):  
Jovan Jovanovic ◽  
Michael Spiteller ◽  
Peter Spiteller
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Resonance Assignments ◽  
Nmr Resonance Assignments ◽  
Coupling Constants ◽  
Two Dimensional ◽  
Nmr Analysis ◽  
Structural Element ◽  
Nmr Parameters ◽  
Methylene Groups

1H, 13Cand two dimensional NMR analyses were applied to determine the NMR parameters of 2-(2?,3?-dihydro-1?H-inden-1?-yl)-1H-indene. The chemical shifts of all the H- and C-atoms, as well as the appropriate coupling constants were determined and the complete NMR resonance assignments of the molecule are given. The predicted patterns of the four different H atoms of the two methylene groups of the indane structural element coincided completely with the complex patterns in the NMR spectra.

Molecular Determinants for Drug-Receptor Interactions. 6. Proton 500 MHz NMR Spectra of the Narcotic Antagonists Naloxone and Naltrexone by Two-Dimensional 1H–1H Chemical Shift Correlation Spectroscopy

1986 ◽  
Vol 41 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Bruno Perly ◽  
Giuseppe C. Pappalardo ◽  
Antonio Grassi
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Relaxation Times ◽  
Chair Conformation ◽  
Correlation Spectroscopy ◽  
Coupling Constants ◽  
Piperidine Ring ◽  
Two Dimensional ◽  
Spectral Parameters ◽  
Narcotic Antagonists

The full analysis of the 1H NMR spectra of naloxone and naltrexone (hydrochloride salts, in 2H2O solution) was performed by using an high-frequency (500 MHz) spectrometer and the recent technique of two-dimensional (2D ) homonuclear shift spectroscopy. The 1H-1H connectivities allowed detection of correlated resonances and assignments of multiplets. The shapes of the contour levels of the COSY 45 spectra were also used to check the relative signs of coupling constants. The refinement of spectral parameters of some component spin-systems of the complex spectra was performed by computerized iterative simulation of patterns.The spectral analysis provided proton coupling constants that allowed to establish a slightly distorted-chair conformation of the piperidine ring in both compounds.The magnetic non-equivalence found for the protons bonded to C-17 atom (part of the N-alkyl fragment) was found to be larger in naltrexone than in the analogous naloxone. This fact, while no significant differences were observable in the chemical shifts of corresponding protons of the rigid molecular backbone of the two narcotic antagonists under study, was assigned to smaller degree of internal conformational flexibility of the N-methylcyclopropyl group in naltrexone with respect to that of the N-methylallyl group in naloxone.The above findings appeared in good agreement with our previously proposed views based on results from 13C relaxation times studies, which suggested the possible correlation of the motional rates of the N-methyl-R group to the pharmacological activity of antagonist compounds. This would consist in a direct correlation between decreasing flexibility of the N-bonded fragment and increasing antagonistic potency.

NMR-spektroskopische Untersuchung des Problems der Valenzisomerie zwischen 1,2-Dithiin und (Z)-But-2-en-1,4-dithion / NMR Spectroscopic Investigation Concerning the Problem of Valence Isomerism between 1,2-Dithiine and (Z)-But-2-ene-1,4-dithione

1988 ◽  
Vol 43 (5) ◽  
pp. 605-610 ◽  
Author(s):  
Reiner Radeglia ◽  
Helmut Poleschner ◽  
Werner Schroth
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
2D Nmr ◽  
Ring Structure ◽  
Coupling Constants ◽  
Nmr Parameters ◽  
Spectrum Simulation ◽  
2D Nmr Spectra ◽  
Transoid Conformation ◽  
C Nmr

3,6-Diaryl-1,2-dithiines and their precursors, (Z,Z)-1,4-bis(organylthio)-buta-1,3-dienes, are investigated by 1H and 13C NMR spectroscopy. The chemical shifts and coupling constants, which are relevant to the investigated problem, are determined and assigned, respectively, by different techniques (shift increments, spectrum simulation, heteronuclear 2D J-resolved and heteronuclear shift correlated 2D NMR spectra, anomalous off-resonance splittings and selective decoupling experiments). The NMR parameters are discussed in relation to the molecular structure. The 13C shift values prove the ring structure of 1,2-dithiines and exclude existence of the valence isomer (Z)-but-2-ene-1,4-dithione (absence of thiocarbonyl resonances). The vicinal 1H,1H coupling constants of the C4 unit of the investigated compounds verify (1) the (Z,Z) configuration of the organylthio groups in 1,4 position of butadiene, (2) the s-transoid conformation of acyclic butadienes and (3) the forced s-cis structure in the cyclic 1,2-dithiines.

Two single-enantiomer amidophosphoesters: a database study on the chirality of (O)2P(O)(N)-based structures

2019 ◽  
Vol 75 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Fahimeh Sabbaghi ◽  
Mehrdad Pourayoubi ◽  
Marek Nečas ◽  
Krishnan Damodaran
Keyword(s):  
Hydrogen Bond ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Two Dimensional ◽  
One Dimensional ◽  
Space Groups ◽  
Structural Database ◽  
Graph Set ◽  
Hydrogen Bonded

The crystal structures of two single-enantiomer amidophosphoesters with an (O)2P(O)(N) skeleton, i.e. diphenyl [(R)-(+)-α-methylbenzylamido]phosphate, (I), and diphenyl [(S)-(−)-α-methylbenzylamido]phosphate, (II), both C20H20NO3P, are reported. In both structures, chiral one-dimensional hydrogen-bonded architectures, along [010], are mediated by N—H...OP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P21. As a result of synergistic co-operation from C—H...O interactions, a two-dimensional superstructure is built including a noncentrosymmetric R 4 4(22) hydrogen-bonded motif. A Cambridge Structural Database survey was performed on (O)2P(O)(N)-based structures in order to review the frequency of space groups observed in this family of compounds; the hydrogen-bond motifs in structures with chiral space groups and the types of groups inducing chirality are discussed. The 2,3 JX –P (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C6H5O groups are different, which is reflected in the different chemical shifts and some coupling constants.

scholarly journals Assignment of 1H and 13C NMR spectral data of diastereomeric acetals directly from their mixture by spectral simulation

2021 ◽  
Vol 19 (2) ◽  
pp. 69-79
Author(s):  
Milan Nesic ◽  
Niko Radulovic
Keyword(s):  
Spectral Data ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Racemic Mixture ◽  
13C Nmr Spectra ◽  
Spectral Simulation ◽  
1H And 13C Nmr ◽  
Methylene Groups

Herein, an NMR spectral analysis was performed of a mixture of diastereomeric acetals synthesized from 2-fluorobenzaldehyde and a racemic mixture of 4-methylpentan-2-ol. The simulated 1H- and 13C-NMR spectra of individual diastereomers, as well as their superimposed and summed spectra, were compared with the obtained experimental spectra. Spin simulation of proton signals was particularly useful for the assignment of the aromatic part of the molecules and of the diastereotopic protons of the methylene groups. The isomer NMR spectral data - chemical shifts, coupling constants, HMBC and NOESY interactions were systematized in appropriate tables and schemes.

13C NMR spectra of sodium naphthalenesulphonates

1985 ◽  
Vol 50 (8) ◽  
pp. 1852-1861 ◽  
Author(s):  
Dobroslav Šnobl ◽  
Antonín Lyčka ◽  
Jaroslav Horyna
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Deuterium Oxide ◽  
Coupling Constants ◽  
13C Nmr Spectra ◽  
Nmr Parameters ◽  
Measured Effect ◽  
C Nmr

13C NMR spectra of thirteen sodium naphthalenesulphonates have been measured in deuterium oxide. The 13C chemical shifts have been assigned, and the nJ(13CH) coupling constants have been measured. Effect of SO3(-) group on the 13C NMR parameters is discussed.

Carbon-13 and nitrogen-14 NMR spectra of 1-(substituted phenyl)pyridinium salts

1980 ◽  
Vol 45 (10) ◽  
pp. 2766-2771 ◽  
Author(s):  
Antonín Lyčka
Keyword(s):  
Heavy Water ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Pyridinium Salts ◽  
Nmr Signals ◽  
C Nmr

The 13C and 14N NMR spectra of 1M solutions of 1-(substituted phenyl)pyridinium salts (4-CH3, 4-OCH3, H, 4-Cl, 4-Br, 4-I, 3-NO2, 4-NO2, 2,4-(NO2)2 (the 13C NMR only)) have been measured in heavy water at 30 °C. The 13C and 14N chemical shifts, the 1J(CH) coupling constants, some 3J(CH) coupling constants, and values of half-widths Δ 1/2 of the 14N NMR signals are given. The 13C chemical shifts of C(4) correlate with the σ0 constants (δC(4) = (1.79 ± 0.097) σ0 + (147.67 ± 0.041)), whereas no correlation of the nitrogen chemical shifts with the σ constants has been found. The half-widths Δ 1/2 correlate with the σ0 constants (Δ 1/2 = (76.2 ± 4.9) σ0 + (106.4 ± 2.2)) except for 1-phenylpyridinium chloride.

1H, 13C and 15N NMR Spectra of Coupling Products of Benzenediazonium Salts with Aliphatic Nitro Compounds and Study of Their E/Z Isomerism

1996 ◽  
Vol 61 (4) ◽  
pp. 589-596 ◽  
Author(s):  
Antonín Lyčka
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Nitro Compounds ◽  
Coupling Constants ◽  
15N Nmr ◽  
Geometrical Isomers ◽  
Sodium Salts ◽  
Aliphatic Nitro Compounds ◽  
Tautomeric Forms

The 1H, 13C and 15N NMR spectra have been measured of coupling products of benzenediazonium salts with nitromethane, nitroethane, 1-nitropropane, 2-nitroethanol and of their sodium salts, and the chemical shifts have been unambiguously assigned. The coupling products have been found to exist only in their hydrazone tautomeric forms. Stereospecific behaviour of the coupling constants 2J(15N,1H) and 2J(15N,13C) in the 15N isotopomers and NOESY have been used to differentiate between the E and Z geometrical isomers. The above-mentioned compounds exist as Z isomers in deuteriochloroform and predominantly (>95%) as E isomers in dimethyl sulfoxide, while the sodium salts are present only as E isomers in dimethyl sulfoxide.

The High Resolution NMR Spectra of Pesticides. II. The DDT-Type Compounds

1969 ◽  
Vol 52 (5) ◽  
pp. 1074-1092 ◽  
Author(s):  
L H Keith ◽  
A L Alford ◽  
A W Garrison
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Aromatic Rings ◽  
Nuclear Magnetic Resonance Spectra ◽  
High Resolution Nmr ◽  
Related Compounds ◽  
Deshielding Effect

Abstract The high resolution nuclear magnetic resonance spectra of the DDT class of pesticides and related compounds are discussed, including a study of the resonances of the aromatic protons as they are affected by various substiluents. The CCl3 moiety on the α-carbon strongly deshields the ortho protons on the aromatic rings, and this deshielding effect is greatly enhanced by substitution of a chlorine ortho rather than para on the aromatic ring. These deshielding effects are explained by a consideration of the electronegativity of the substituents and the stereochemistry of the molecule. The chemical shifts and coupling constants are tabulated.

Structural Characterization of Natural Products By Means of Quantum Chemical Calculations of NMR Parameters: New insights

2021 ◽  
Author(s):  
Fabio Luiz Paranhos Costa ◽  
Ana Carolina Ferreira de Albuquerque ◽  
Rodolfo Goetze Fiorot ◽  
Luciano Morais Lião ◽  
Lucas Haidar Martorano ◽  
...  
Keyword(s):  
Natural Products ◽  
Structural Characterization ◽  
Quantum Chemical ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Nmr Parameters ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

The calculation of NMR parameters for natural products was pioneered by Bifulco and coworkers in 2002. Since then, modelling 1H and 13C chemical shifts and spin-spin coupling constants for this...

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