1H and 13C NMR study of (X-phenyl)-5-nitro-2-furylvinyl ethers

1980 ◽  
Vol 45 (12) ◽  
pp. 3557-3563 ◽  
Author(s):  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Daniel Végh
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Furan Ring ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
H Nmr ◽  
Nmr Study ◽  
Hammett Σ Constants ◽  
C Nmr

Reaction of 5-nitro-2-furylvinyltrimethylammonium bromide with substituted phenolates gave (E)- and (Z)-(X-phenyl)-5-nitro-2-furylvinyl ethers. The preffered s-cis and s-trans orientations of the furan ring in Z and E isomers, respectively, were determined by 1H NMR spectroscopy. To study the extent of p-π conjugation, 13C NMR spectra of compounds under investigation have also been measured and interpreted. Chemical shifts for ethylenic carbons and protons were correlated with Hammett σ constants.

Preparation, 1H and 13C NMR, and ab initio/IGLO study of mono-O-protonated deltic acid and theoretical investigation of di-, tri-, and tetra-O-protonated deltic acids

1999 ◽  
Vol 77 (5-6) ◽  
pp. 525-529 ◽  
Author(s):  
GK Surya Prakash ◽  
Golam Rasul ◽  
George A Olah ◽  
Ronghua Liu ◽  
Thomas T Tidwell
Keyword(s):  
Nmr Spectroscopy ◽  
Ab Initio ◽  
Theoretical Investigation ◽  
13C Nmr ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Molar Solution ◽  
Protonated Species ◽  
C Nmr

The hitherto elusive mono-O-protonated deltic acid C3O3H3+ was prepared by protolysis of di-tert-butoxy deltate in FSO3H-SO2ClF and in FSO3H:SbF5 (Magic Acid; 1:1 molar solution) in SO2ClF as solvent at -78°C and was characterized by 1H and 13C NMR spectroscopy. The structure and NMR chemical shifts were also calculated by the ab initio/IGLO method. No NMR evidence was found for persistent di-O-protonated deltic acid under these conditions, although a limited equilibrium with the mono-O-protonated species can be involved. Di-, tri-, and tetra-O-protonated deltic acids were also studied by ab initio/IGLO method.Key words: protonated deltic acid, aromaticity, superacids, NMR spectroscopy, ab initio and IGLO calculations.

13C-NMR-Spektroskopie an polycyclischen Aromaten, II. Die 13C-NMR-Spektren von 1- und 2-Fluornaphthalin. Überprüfung der Signalzuordnung und Untersuchung der Substituenteneffekte auf die chemischen Verschiebungen / 13C NMR Spectroscopy of Polycyclic Aromatics, II. The 13C NMR Spectra of 1- and 2-Fluoronaphthalene. Reexamination of Signal Assignments and Investigation of Substituent Effects on Chemical Shifts

1975 ◽  
Vol 30 (9-10) ◽  
pp. 788-793 ◽  
Author(s):  
Ludger Ernst
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Substituent Effects ◽  
13C Nmr Spectroscopy ◽  
Polycyclic Aromatics ◽  
H Nmr ◽  
Iterative Analysis ◽  
C Nmr

During a reinvestigation of the 13C NMR spectra of 1-fluoronaphthalene (1) and of 2-fluoronaphthalene (2) at 20 and 25.16 MHz, uncertainties that existed in the literature about signal assignments for 1 could be cleared. In the spectral analyses for 2 given so far, five out of ten signals were incorrectly assigned. The corrected assignment is supported by extensive 13C{1H} double resonance experiments, by recording of proton-coupled 13C and 13C{19F} spectra and by off-resonance 13C{1H} noise-decoupling. The results show a strong + M-effect of the fluorine substituents on 13C chemical shifts similar to the effects of OH and OCH3 groups. 1H NMR spectra of 1 and 2 could be partially assigned by decoupling of the 19F resonances and by iterative analysis.

Increments for 1H and 13C NMR chemical shifts in pinacol arylboronates

2012 ◽  
Vol 90 (1) ◽  
pp. 71-74
Author(s):  
Di Qiu ◽  
Zhitong Zheng ◽  
Fanyang Mo ◽  
Yan Zhang ◽  
Jianbo Wang
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Cross Coupling Reactions ◽  
C Nmr

Arylboronates are important compounds widely used in cross-coupling reactions. By analyzing the NMR spectra data of a variety of pinacol arylboronates, we have determined the increments for 1H and 13C NMR chemical shifts caused by a pinacol boronate substituent in the benzene ring. These data can be used in the estimation of chemical shifts of aromatic pinacol boronates.

Substituent Influences on the Keto-Enol Tautomerism in 1-(2-Hydroxyphenyl)-3-α-and -β-naphthylpropane-1,3-diones Monitored by 1H and 13C NMR Spectroscopy

2000 ◽  
Vol 55 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Jorge L. Jios ◽  
Helmut Duddeck
Keyword(s):  
Nmr Spectroscopy ◽  
Long Range ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
Tautomeric Equilibria ◽  
Hmbc Correlation ◽  
C Nmr

Synthesis of 18 1-(2-hydroxyphenyl)-3-α- and -β-naphthylpropan-1,3-diones is described. Their 1H and 13C NMR spectra were completely and unambiguously assigned using a combination of both homo- and heteronuclear (gs-COSY ), 1H -detected heteronuclear one-bond (gs-HMQC ) and long-range (gs-HMBC) correlation experiments. Substituent and conformation effects on the tautomeric equilibria were identified and interpreted in terms of steric and electronic contributions.

Chemistry of chromotropic acid. 1H and 13C NMR spectroscopy of chromotropic acid and its derivatives

1991 ◽  
Vol 69 (8) ◽  
pp. 1207-1211 ◽  
Author(s):  
Paris E. Georghiou ◽  
Chi Keung (Jimmy) Ho ◽  
Chester R. Jablonski
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Deuterium Oxide ◽  
13C Nmr Spectroscopy ◽  
Chromotropic Acid ◽  
Hydroxyl Groups ◽  
Two Dimensional ◽  
1H And 13C Nmr ◽  
C Nmr

The 1H and 13C NMR spectra of chromotropic acid (CTA) (4,5-dihydroxy-2,7-naphthalenedisulphonic acid) have been unambiguously assigned. Proton NOED spectra were used to show the proximity of both H-3 and H-6 and the hydroxyl groups. Two-dimensional 1H–13C NMR correlation spectra of CTA, of its corresponding diacetoxy derivative, and of 3-bromo- and 3,6-dibromo-CTA support the assignments. A regioselective deuterium exchange reaction of the C-3 and C-6 protons of CTA with deuterium oxide was observed during the NMR experiments. This latter finding is strongly indicative of the mode of formation, and of the nature of the chromogen formed in the reaction of CTA with formaldehyde in the well-known CTA-formaldehyde analytical reaction. Key words: chromotropic acid, 3-bromochromotropic acid, 3,6-dibromochromotropic acid.

Preparation of β-D-Glucopyranosyl Derivatives of 1,6:2,3- and 1,6:3,4-Dianhydro-β-D-hexopyranoses and Their 1H and 13C NMR Spectra

1995 ◽  
Vol 60 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Miloš Buděšínský ◽  
Miloslav Černý ◽  
Ivan Černý ◽  
Stanislav Sámek ◽  
Tomáš Trnka
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Derivatives Of ◽  
C Nmr

The corresponding acetylated and free 2-O- and 4-O-glucosyl derivatives of dianhydrohexoses Ib - VIIb and Ic - VIIc have been obtained by the reactions of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (IX) with 1,6:3,4- and 1,6:2,3-dianhydro-β-D-hexopyranoses (Ia - VIIa). Structure of the products and the effects of glycosylation upon chemical shifts and conformations of the disaccharides prepared have been studied using 1H and 13C NMR spectra.

1H and 13C NMR Spectra of Technically Important Sodium 1- and 2-Aminonaphthalenesulfonates

1993 ◽  
Vol 58 (6) ◽  
pp. 1378-1387 ◽  
Author(s):  
Josef Jirman
Keyword(s):  
13C Nmr ◽  
Sulfonic Acid ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Deuterium Oxide ◽  
Acid Group ◽  
Sulfonic Acid Group ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
C Nmr

The 1H and 13C NMR spectra of twenty-one technically important sulfonated 1- and 2-naphthylamines have been measured in deuterium oxide. The substituent chemical shifts (SCS) of a sulfonic acid group on naphthylamine skeleton have been calculated from the chemical shifts assigned.

Carbon-13 nuclear magnetic resonance spectra of E-silyl-alkenes

1980 ◽  
Vol 58 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Constantinos A. Tsipis ◽  
Constantinos A. Tsoleridis
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
Carbon Atom ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
H Nmr ◽  
Nuclear Magnetic Resonance Spectra ◽  
C Nmr

Carbon-13 nmr chemical shifts of a number of E-silyl-alkenes containing the silyl substituent at an sp2 carbon atom are presented. Assignments of the chemical shifts have been made by noting systematic variations in the spectra with changes in substituents and by comparison of the chemical shifts to those of the corresponding unsubstituted alkenes. The substituent effects observed were explained on the basis of the π-acceptor ability of the silyl substituents and the structure of the molecules. Comparing the 13C nmr spectra of the E-silyl-alkenes and those of the corresponding unsubstituted alkenes, differential chemical shifts have been obtained which can be used as empirical substituent parameters for the prediction of the 13C nmr spectra of other E-silyl-alkenes not yet studied. It was also demonstrated that 13C nmr spectroscopy can be used without resorting to special techniques (gated decoupling and the addition of paramagnetics) as an alternative method to the 1H nmr for the quantitative analysis of mixtures of regio-isomer E-silyl-alkenes.

scholarly journals Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

2005 ◽  
Vol 60 (1-2) ◽  
pp. 106-112 ◽  
Author(s):  
B. Thimme Gowda ◽  
Mahesha Shetty ◽  
K. L. Jayalakshmi
Keyword(s):  
Solid State ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
1H And 13C Nmr ◽  
Methyl Group ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
C Nmr

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN−H, absorb in the range 3285 - 3199 cm−1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm−1 and 1177 - 1148 cm−1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm−1 and 1304 - 1168 cm−1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X’C6H4SO2- and 4-X’C6H4SO2NH- groups in 4-X’C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X’C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

1H and 13C NMR Spectroscopic Studies of the Complexation of Phenylenedioxydiacetamides with Calcium and Potassium Cations in Solution

1984 ◽  
Vol 39 (10) ◽  
pp. 1375-1379 ◽  
Author(s):  
Whei Oh Lin ◽  
Maria C. B. V. de Souza ◽  
Helmut G. Alt
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Methylene Chloride ◽  
Spectroscopic Studies ◽  
Acetonitrile Solution ◽  
Chelating Ligands ◽  
1H And 13C Nmr ◽  
Coordination Modes ◽  
H Nmr ◽  
C Nmr

Phenylenedioxydiacetamides are examples of noncyclic ionophors that are able to form 2:1 complexes with the cations Ca2+ and K+ in acetone, methylene chloride or acetonitrile solution. The chelation abilities and coordination modes of 12 derivatives were investigated systematically by IR, 1H NMR and 13C NMR spectroscopy. The results indicate that only the 1,2-phenylenedioxydiacetam ides function as ligands; while the 1,3-derivatives do not coordinate. The ionophors 1-8 act as tetradentate chelating ligands with all four oxygen atoms involved in bonding to the cation. Irrespective of its charge, each cation is coordinated by two ionophors.

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