(1,2-Bis(diphenylphosphino)ethane)(.eta.3-1-arylallyl)palladium Tetrafluoroborates. Distribution of the Positive Charge Density by Correlation of NMR Chemical Shifts with Hammett Substituent Constants

1995 ◽  
Vol 14 (5) ◽  
pp. 2463-2469 ◽  
Author(s):  
Ramon Malet ◽  
Marcial Moreno-Manas ◽  
Teodor Parella ◽  
Roser Pleixats
Keyword(s):  
Charge Density ◽  
Positive Charge ◽  
Chemical Shifts ◽  
Nmr Chemical Shifts ◽  
Substituent Constants

scholarly journals Solvent-Free Synthesis and Spectral Linearity of Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamides

2013 ◽  
Vol 13 ◽  
pp. 160-174 ◽  
Author(s):  
Ganesamoorthy Thirunarayanan ◽  
K.G. Sekar
Keyword(s):  
Statistical Analysis ◽  
Microwave Irradiation ◽  
Spectral Data ◽  
Chemical Shifts ◽  
Solvent Free ◽  
Nmr Chemical Shifts ◽  
Substituent Constants ◽  
Substituted Benzaldehydes ◽  
Solvent Free Synthesis ◽  
Spectral Group

Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamide derivatives have been synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of 2-amino-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta [b]thiophene-3-carboxamide and various substituted benzaldehydes in microwave irradiation. The yield of the imine-carboximido derivatives has been found to be more than 85 %. The purity of all imine-carboximido derivatives has been checked using their physical constants and spectral data. The spectral data of the imine-carboximido derivatives such as infrared ν (cm-1) of CO, NH, C-N, C-Cl, C-F, C=N, and the NMR chemical shifts (δ, ppm) of NH, CH, CO and C=N have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis, the effects of substituent on the above spectral group absorptions have been discussed.

scholarly journals Effect of Substituents on Phenazine Derivatives by Spectral Studies

2015 ◽  
Vol 48 ◽  
pp. 114-122
Author(s):  
G. Thirunarayanan ◽  
I. Muthuvel ◽  
V. Sathiyendiran
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Spectral Data ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
Nmr Chemical Shifts ◽  
Effect Of Substituents ◽  
Substituent Constants ◽  
Infrared Frequencies ◽  
C Nmr

A series of eleven substituted dipyrido[3,2-a; 2′,3′-c]phenazine derivatives have been synthesized and examined their purities by literature method. The infrared and 13C NMR spectral data of prepared phenazines were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the results of statistical analysis, the effect of substituents on the infrared frequencies (ν, cm-1) and 13C nmr chemical shifts(δ, ppm) has been studied.

Chemometrical analysis of substituent effects on 13C and 15N NMR chemical shifts in 1-aroyl-3-substituted thioureas

1989 ◽  
Vol 54 (9) ◽  
pp. 2399-2407 ◽  
Author(s):  
Oldřich Pytela ◽  
Josef Jirman ◽  
Antonín Lyčka
Keyword(s):  
Latent Variables ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
The Other ◽  
15N Nmr ◽  
Nmr Chemical Shifts ◽  
Additional Constant ◽  
Substituent Constants ◽  
Derivatives Of ◽  
C Nmr

The methods of conjugated deviations and regression analysis have been used to study the substituent effects on 13C and 15N NMR chemical shifts of 12 derivatives of 1-aroyl-3-phenylthiourea and 1-aroyl-3-methylthiourea. The 13C NMR chemical shifts can be described by two latent variables, one univocally correlated with the Hammett substituent constants (r = 0.993) and the other reflecting the increased shielding of the nuclei due to overlap of the adjacent bond electrons as a consequence of electron-donor or electron-acceptor character of the substituents.This effect is less pronounced with the 15N nuclei. Application of dual substituent constants σR, σF with the additional constant σα describing the polarization has failed in giving sufficiently close correlations and explanation of the substituent effect found.

scholarly journals A study of substituent effects on the NH bond in alkyl and aryl 4,6-disubstituted-3-cyano-2-pyridones

2007 ◽  
Vol 72 (12) ◽  
pp. 1229-1236 ◽  
Author(s):  
Milica Misic-Vukovic ◽  
Slobodanka Jovanovic ◽  
Dusan Mijin ◽  
Janos Csanadi ◽  
Dejan Djokovic
Keyword(s):  
1H Nmr ◽  
Chemical Shifts ◽  
Computer Calculation ◽  
Substituent Effects ◽  
Nmr Chemical Shifts ◽  
Ir Frequencies ◽  
Substituent Constants

Substituent effects on the IR stretching frequencies and 1H-NMR chemical shifts of the pyridone NH group in 4- and 6-disubstituted alkyl and aryl 3-cyano- 2-pyridones were investigated. The bands most sensitive to substituent effects from the broad and multiple IR NH band for each compound were selected by a computer calculation. The selected values of the IR frequencies and the determined 1H-NMR chemical shifts were subjected to LFER analysis, by correlations with the Hamett ?m/p and Swain-Lupton F and R substituent constants.

scholarly journals Infrared and NMR Spectral Hammett Correlations in 4-(2-Naphthyl)-5,6-Dihydro-6-(Substituted Phenyl)-4H-1,3-Oxazine-2-Amines

2014 ◽  
Vol 27 ◽  
pp. 38-46
Author(s):  
Ganesamoorthy Thirunarayanan ◽  
S. Pazhamalai ◽  
K.G. Sekar
Keyword(s):  
Regression Analysis ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Ir And Nmr Spectra ◽  
Nmr Chemical Shifts ◽  
Substituent Constants ◽  
Single Regression

A series containing ten titled compounds have been synthesised and recorded the IR and NMR spectra. From the spectra the infrared νNH, C=N, C-O-C stretches, NMR chemical shifts of (δ, ppm) NH and C=N were assigned and correlated with Hammett substituent constants, F and R parameters using single regression analysis. From the results, the effects of substituent on the above spectral frequencies were discussed.

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