The ortho effect in ortho-substituted 2-(X-benzal)-1,3-indanediones, 3-(2-X-benzal)phthalides and 3-(2-X-benzal)-5,6-dihydro-4,7-dithiaphthalides: A 1H-NMR study

1980 ◽  
Vol 45 (5) ◽  
pp. 1589-1594 ◽  
Author(s):  
Ľudovít Krasnec ◽  
Eva Solčániová ◽  
Pavol Hrnčiar
Keyword(s):  
Chemical Shift ◽  
Field Effect ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Methine Proton ◽  
Electronic Effects ◽  
H Nmr ◽  
Nmr Study ◽  
Considerable Distortion ◽  
The Common

The 1H-NMR spectra of ortho-substituted 2-(X-benzal)-1,3-indanediones, 3-(2-X-benzal)-phthalides and 3-(2-X-benzal)-5,6-dihydro-4,7-dithiaphthalides have been studied. The chemical shifts observed for the methine proton were correlated with various constants of the substituents. In addition to simple correlations, two- and three-parameter correlations were also made. Statistically most important one-parameter correlations were observed for σp-constants. Apart from the common electronic effects, in the transfer of effects of the substituents from the ortho-position upon the chemical shift of the methine proton the field effect plays also an important role. The deviations observed in the case of substances substituted in both ortho-positions confirm the assumed considerable distortion of the coplanarity of the studied systems.

17O NMR Spectra of Acylated Ureas and Thioureas

1992 ◽  
Vol 57 (6) ◽  
pp. 1278-1281 ◽  
Author(s):  
Josef Jirman ◽  
Pavel Pech
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Electronic Effects ◽  
17O Nmr ◽  
Nmr Chemical Shifts

17O NMR spectra of ten acyl- and diacylureas (I-V) and thioureas (VII-X) were measured. 17O NMR chemical shifts of the ureido oxygen in the ureas range from 240 to 310 ppm, those of the acyl oxygens from 377 to 400 ppm (acetyl groups) and 359 to 389 ppm (benzoyl groups), the half-widths being tens to hundreds Hz. Acylation of urea to the diacyl stage has an almost twice as large effect on the chemical shift of the ureido oxygen than has the monoacylation. From the viewpoint of 17O NMR shifts, no significant differences has been found in the influence of ureido and thioureido groups on the transfer of electronic effects in 1,3-diacylureas and 1,3-diacylthioureas.

13C NMR study of 3-(X-benzal)phthalides and 2-(X-benzal)-1,3-indanediones

1980 ◽  
Vol 45 (10) ◽  
pp. 2772-2778 ◽  
Author(s):  
Eva Solčániová ◽  
Pavol Hrnčiar ◽  
Tibor Liptaj
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Electronic Effect ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Carbonyl Groups ◽  
Aryl Group ◽  
Nmr Study ◽  
Derivatives Of ◽  
C Nmr

13C NMR spectra of 14 derivatives of 3-(X-benzal)phthalides (I) and 10 derivatives of 2-(X-benzal)-1,3-indanediones (II) were investigated. The correlation of 13C chemical shifts of carbon atoms of the phthalide ring with σ-constants showed that the electronic effect of substituents was transmitted from the benzylidene group of 3-(X-benzal)phthalides on the chemical shift of the carbonyl group not only through oxygen, but also through the aromatic ring of the phthalide moiety. The transmission of substituent effects in 2-(X-benzal)-1,3-indanediones on the chemical shift of the carbonyl groups was more pronounced on the carbonyl, which is in the trans-arrangement with respect to the aryl group. This phenomenon was also observed at carbon atoms of the benzene ring of the indanedione moiety closer to the trans-CO group.

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.

31P-NMR-und 57Fe-Mößbauer-spektroskopische Untersuchungen an Pentacyano(phosphan oder phosphit)ferraten(II) / 31P NMR and 57Fe Mössbauer Spectroscopic Studies on Pentacyano(phosphane or phosphite)ferrates(II)

1985 ◽  
Vol 40 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Hidenari Inoue ◽  
Masahiro Sasagawa ◽  
Ekkehard Fluck
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
31P Nmr ◽  
Chemical Shifts ◽  
Spectroscopic Studies ◽  
57Fe Mössbauer ◽  
Mossbauer Spectra ◽  
H Nmr ◽  
Phosphine Complexes ◽  
Low Field

The 31P{1H}NMR spectra for a series of pentacyanoferrates(II) of the type Na3[Fe(CN)5L] (L = phosphine or phosphite) have been measured. A low field chemical shift range of 48.1-88.7 ppm for phosphine complexes and of 32.5-48.4 ppm for phosphite complexes is observed when one compares free vs. coordinated ligands. The correlation between chemical shifts in the 31P NMR spectra and isomeric shifts in the Mössbauer spectra is investigated and discussed

Preparation and properties of β-ketosulphones of 5-nitrofuran series. Study of transfer of electronic effects through sulphone group

1982 ◽  
Vol 47 (2) ◽  
pp. 617-621 ◽  
Author(s):  
Dana Polakovičová ◽  
Adolf Jurášek ◽  
Vladimír Kvasnička
Keyword(s):  
Linear Dependence ◽  
Quantum Chemical ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Electronic Effects ◽  
H Nmr ◽  
Physical Measurements ◽  
Hammett Constants ◽  
Series Study ◽  
Proton Chemical Shifts

A series of 2-(5-nitro-2-furyl)-2-oxoethylarylsulphones have been synthesized by reaction of 5-nitro-2-bromoacetylfuran with sodium p-X-benzenesulphinates (where X = H, CH3, OCH3, CH3CONH, NH2, N(CH3)2, Cl, NO2) and used for a study of transfer of electronic effects of the substituent through SO2 group. The found linear dependence between the proton chemical shifts in 1H NMR spectra (and pKa values of the CH2 group) and the Hammett constants of the substituents proves the existence of the transfer through SO2 group. The results of physical measurements were compared with the data obtained by quantum-chemical calculations using the EHT method.

119Sn, 13C and 1H NMR Spectra of Tris(1-butyl)stannyl D-Glucuronate

1997 ◽  
Vol 62 (8) ◽  
pp. 1169-1176 ◽  
Author(s):  
Antonín Lyčka ◽  
Jaroslav Holeček ◽  
David Micák
Keyword(s):  
Chemical Shift ◽  
Carbonyl Group ◽  
1H Nmr ◽  
Equatorial Plane ◽  
Title Compound ◽  
Nmr Spectra ◽  
Hydroxyl Groups ◽  
Carboxylic Group ◽  
H Nmr ◽  
Oxygen Atoms

The 119Sn, 13C and 1H NMR spectra of tris(1-butyl)stannyl D-glucuronate have been measured in hexadeuteriodimethyl sulfoxide, tetradeuteriomethanol and deuteriochloroform. The chemical shift values have been assigned unambiguously with the help of H,H-COSY, TOCSY, H,C-COSY and 1H-13C HMQC-RELAY. From the analysis of parameters of 119Sn, 13C and 1H NMR spectra of the title compound and their comparison with the corresponding spectra of tris(1-butyl)stannyl acetate and other carboxylates it follows that in solutions of non-coordinating solvents (deuteriochloroform) the title compound is present in the form of more or less isolated individual molecules with pseudotetrahedral environment around the central tin atom and with monodentately bound carboxylic group. The interaction of tin atom with oxygen atoms of carbonyl group and hydroxyl groups of the saccharide residue - if they are present at all - are very weak. In solutions in coordinating solvents (hexadeuteriodimethyl sulfoxide or tetradeuteriomethanol), the title compound forms complexes with one molecule of the solvent. Particles of these complexes have a shape of trigonal bipyramid with the 1-butyl substituents in equatorial plane and the oxygen atoms of monodentate carboxylic group and coordinating solvent in axial positions.

A 15N, 13C, and 1H NMR study of reaction products from arylguanidines and chloroformate esters

1991 ◽  
Vol 56 (7) ◽  
pp. 1505-1511 ◽  
Author(s):  
Antonín Lyčka ◽  
Karel Palát
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Reaction Products ◽  
H Nmr ◽  
Nmr Study

The 15N, 13C, and 1H NMR spectra of the reaction products from arylguanidines with two mols of chloroformate esters have been measured. With application of the corresponding 15N isotopomer it has been proved that the reaction products have the structures IIIa-IIIc.

scholarly journals 13C and 1H NMR Spectra of Synthetic (25R)-5α-Spirostanes

1999 ◽  
Vol 23 (1) ◽  
pp. 48-49
Author(s):  
Martín A. Iglesias Arteaga ◽  
Carlos S. Pérez Martinez ◽  
Roxana Pérez Gil ◽  
Francisco Coll Manchado
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
1H Nmr Spectra ◽  
H Nmr ◽  
C 23 ◽  
Main Effects ◽  
Nmr Signals

The assignment of 13C and 1H NMR signals of synthetic (25 R)-5α-spirostanes is presented; the main effects on chemical shifts due to substitution at C-23 are briefly discussed.

Chemical shifts of charge-transfer complexes and Buckingham equation

1990 ◽  
Vol 55 (9) ◽  
pp. 2131-2137
Author(s):  
Mahboob Mohammad ◽  
Ather Yaseen Khan ◽  
Tariq Mahmood ◽  
Ismat Fatima ◽  
Riffat Shaheen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Nmr Spectra ◽  
Charge Transfer Complex ◽  
Chemical Shifts ◽  
Charge Transfer Complexes ◽  
Aprotic Solvents ◽  
Reaction Field ◽  
H Nmr ◽  
Spherical Cavities ◽  
Dipolar Aprotic Solvents

The 1H NMR spectra of the charge-transfer complex of 1-ethyl-4-methoxycarbonylpyridinium iodide have been recorded in various dipolar aprotic solvents. An attempt is made to interpret the chemical shifts in terms of Buckingham's reaction field equation for spherical cavities. A linear dependence has been found between the δ(2,6) values and the square of dielectric function for a spherical cavity, which confirms the validity of the Buckingham equation for this class of compounds.

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