Carbon-13 substituent-induced chemical shifts in benzene derivatives: Substituted anilines

1991 ◽  
Vol 56 (2) ◽  
pp. 368-385 ◽  
Author(s):  
Miloš Buděšínský ◽  
Dan Johnels ◽  
Ulf Edlund ◽  
Otto Exner
Keyword(s):  
Aromatic Compounds ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Benzene Derivatives ◽  
Substituted Anilines ◽  
Ring Carbon ◽  
Close Resemblance ◽  
Substituent Constants

Carbon-13 NMR spectra are reported for 59 meta- and para-substituted anilines in deuterochloroform or in its mixture with hexadeuterodimethyl sulphoxide. The substituent-induced chemical shifts (SCS) of ring carbon atoms in position 4 correlate well with dual substituent parameters (DSP). In the remaining positions correlations are not satisfactory with any kind of known substituent constants. There is, however, a close resemblance between SCS in the same position of meta- and para-substituted anilines and even in other series of aromatic compounds.

NMR-spektroskopische Untersuchungen über zwischenmolekulare Wechselwirkungen bei Benzolderivaten und Pyrrol / NMR-Spectroscopic Investigation of the Intermolecular Reactions of Benzene Derivatives and Pyrrole

1969 ◽  
Vol 24 (11) ◽  
pp. 1365-1370 ◽  
Author(s):  
H.-H. Perkampus ◽  
U. Krüger ◽  
W. Krüger
Keyword(s):  
Dipole Moment ◽  
Temperature Dependence ◽  
Aromatic Compounds ◽  
Spectroscopic Investigation ◽  
Chemical Shifts ◽  
Benzene Derivatives ◽  
Intermolecular Reactions ◽  
Proton Chemical Shifts

The proton chemical shifts of aromatic compounds are strongly concentration dependent. Moreever, for molecules with a dipole moment a temperature dependence of the proton chemical shifts is observed. For hemellitone, p-methylanisole, o-chlortoluene, p-chlortoluene, pyrrole and N-methyl-pyrrole the enthalpies of a dipole-dipole association between -0,7 and -1,8 Kcal could be estimated by NMR measurements combined with the temperature dependence in the whole range of the molefraction (0 → 1).

ChemInform Abstract: Carbon-13 Substituent-Induced Chemical Shifts in Benzene Derivatives: Substituted Anilines

ChemInform ◽  
2010 ◽  
Vol 22 (25) ◽  
pp. no-no
Author(s):  
M. BUDESINSKY ◽  
D. JOHNELS ◽  
U. EDLUND ◽  
O. EXNER
Keyword(s):  
Chemical Shifts ◽  
Benzene Derivatives ◽  
Substituted Anilines

Multinuclear (1H, 13C and 15N) Magnetic Resonance Spectroscopy and Substituent Effects on N-Phenoxyethylanilines

2002 ◽  
Vol 57 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Jorge L. Jios ◽  
Gustavo P. Romanelli ◽  
Juan C. Autino ◽  
Damian Magiera ◽  
Helmut Duddeck
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Substituent Effect ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
The Other ◽  
Resonance Spectroscopy ◽  
Phenyl Rings ◽  
Substituent Constants

1H, 13C and 15N NMR spectra of twenty substituted N-phenoxyethylanilines 1-20 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) gradient-selected correlation experiments. Correlations between chemical shifts and substituent constants are analyzed separately for both phenyl rings using variable substituents para to the fixed substituent -OCH2CH2NHC6H5 (series I) and -NHCH2CH2OC6H5 (series II), respectively. The correlation coefficient for chemical shifts vs. a linear combination of inductive and resonance substituent constants is high and improves when only the six values, corresponding to each para-monosubstituted series, were used. For nitrogen chemical shifts excellent linear dependences were obtained. The results show that the ethylene chain is not able to transmit the substituent effect from one aromatic ring to the other.

Carbon-13 Substituent-Induced Chemical Shifts: Monosubstituted Benzene Derivatives

1992 ◽  
Vol 57 (3) ◽  
pp. 497-507 ◽  
Author(s):  
Otto Exner ◽  
Miloš Buděšínský
Keyword(s):  
Benzene Ring ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
The Other ◽  
Correlation Equations ◽  
Benzene Derivatives ◽  
Complex Mechanism ◽  
Monosubstituted Benzene ◽  
Resonance Effects ◽  
Other Hand

Carbon-13 NMR spectra of twelve monosubstituted benzene derivatives were measured in deuterochloroform. Together with the literature data a set of 35 systematically chosen substituents was obtained on which some thirty correlation equations were tested. As anticipated only substituent chemical shifts (SCS) in the position 4 are controlled by inductive and resonance effects, and can be correlated by dual substituent parameters (DSP). For the other positions DSP were not successful and more sophisticated equations are not much telling. On the other hand, the direct relations between two series of SCS are usually more precise and simple to understand. It is concluded that SCS in benzene ring need not be controlled by too complex mechanism but simply by different factors than by inductive and resonance effects.

13C and 15N NMR spectra of 3-methyl-1-phenylpyrazole-4,5-dione 4-(4'-substituted phenyl)hydrazones

1987 ◽  
Vol 52 (3) ◽  
pp. 727-735 ◽  
Author(s):  
Antonín Lyčka ◽  
Tibor Liptaj ◽  
Josef Jirman
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
15N Nmr ◽  
Substituent Constants ◽  
Phenyl Hydrazones

13C and 15N NMR spectra have been measured of eleven 3-methyl-1-phenylpyrazole-4,5-dione 4-(4'-substituted phenyl)hydrazones (I). The 13C chemical shifts of the non-substituted compound I have been assigned with the use of the 1J(13C, 13C) coupling constants obtained from the 1D-INADEQUATE spectrum. The greatest changes in chemical shifts of the compounds I connected with the substituent at 4'-position have been observed for the nitrogen atoms Nα, Nβ, N2 and carbon C(4). These substitution chemical shifts have been correlated with the substituent constants by means of the equations SCS = ρ1σ1 + ρRσR + const., where σR means one of the values σR0, σRBA, σR-, or σR+. The best correlations have been obtained for the combinations Nα - σRBA, Nβ - σR-, N2 - σR0, and C(4) - σR0. The 15N substituent chemical shifts of the nitrogen atoms Nα and Nβ of compounds I have been compared with the analogous values of 4-substituted trans-azobenzenes.

scholarly journals IR and NMR Spectral Studies of Some 4-(6-methoxy-2-naphthyl)-5,6-dihydro-6-(Substituted Phenyl)-4H-1,3-Oxazine-2-Amines: Assessment of Substituent

2013 ◽  
Vol 23 ◽  
pp. 109-116
Author(s):  
Ganesamoorthy Thirunarayanan
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Statistical Analyses ◽  
Spectral Studies ◽  
Ir And Nmr Spectra ◽  
Effect Of Substituents ◽  
H Nmr ◽  
Substituent Constants ◽  
C Nmr

A series containing thirteen title compounds were synthesized and recorded IR and NMR spectra. The infrared νNH, C=N(cm-1)stretches, 1H NMR δNH, 13C NMR δC=N(ppm) chemical shifts of synthesized oxazine amines were assigned and correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses, the effect of substituents on the above spectral frequencies can be discussed.

scholarly journals Solvent-Free Synthesis and Assessment of Substituent Effects from IR & NMR Spectra of some Substituted Benzylidene-5-Ethyl-1,3,4-Thiadiazole-2-Amines

2013 ◽  
Vol 24 ◽  
pp. 89-98
Author(s):  
Ganesamoorthy Thirunarayanan
Keyword(s):  
Spectroscopic Data ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Linear Regression Analysis ◽  
Substituent Effects ◽  
Solvent Free ◽  
Substituent Constants ◽  
Multi Linear Regression ◽  
Solvent Free Synthesis ◽  
Spectral Group

A series containing ten titled compounds were synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of substituted benzaldehydes and 2-amino-5-ethyl-1,3,4-thiadiazole under microwave irradiation. The yields of prepared amines are more than 90%. The synthesized amines were characterized by their physical constants and spectroscopic data reported in literature earlier for known compounds. The assigned spectral group frequencies such as infrared νC=N, C-S-C, N-N (cm-1) and NMR chemical shifts (δ, ppm) of CH, C=N have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analyses, the effects of substituent on the above spectral data have been discussed.

Notizen: 13C NMR Spectra of Alkyl Substituted Pyrylium Salts

1975 ◽  
Vol 30 (7-8) ◽  
pp. 654-655 ◽  
Author(s):  
A. T. Balaban ◽  
V. Wray
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
13C Nmr Spectra ◽  
Charge Densities ◽  
Ring Carbon ◽  
Pyridinium Cation ◽  
Pyrylium Salts ◽  
Isoelectronic Series ◽  
Alkyl Substitution ◽  
Alkyl Benzenes

The 13C chemical shifts of several alkylsubstituted pyrylium salts are presented. Charge densities in the isoelectronic series benzene, pyridine, pyridinium cation and pyrylium cation, calculated from INDO M. O. theory, are shown to correlate well with the ring carbon 13C chemical shifts. The effect of alkyl substitution on ring carbon 13C chemical shifts in the pyrylium salts are shown to correlate with those of the alkyl benzenes.

scholarly journals NMR Spectral Correlations in Some Tröger’s Bases

2013 ◽  
Vol 23 ◽  
pp. 1-11
Author(s):  
Ganesamoorthy Thirunarayanan ◽  
M. Suresh
Keyword(s):  
Spectroscopic Data ◽  
Electrophilic Substitution ◽  
Chemical Shifts ◽  
Acid Catalyst ◽  
Electrophilic Substitution Reaction ◽  
Regression Analyses ◽  
Substituted Anilines ◽  
Anhydrous Alcl3 ◽  
Lewis Acid Catalyst ◽  
Substituent Constants

Some Tröger’s bases have been synthesised from substituted anilines and paraformaldehyde in presence of Lewis acid catalyst such as anhydrous AlCl3, through electrophilic substitution reaction. The purities of these Tröger’s bases have been checked by their physical constants and spectroscopic data published earlier in the literature. The NMR chemical shift (δ, ppm) of methylene protons and carbon were assigned. The assigned methylene protons and carbon chemical shifts (δ, ppm) of synthesised Tröger’s bases have been correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituent on methylene protons and carbon were discussed.

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