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.

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 13C- and 1H-NMR substituent-induced chemical shifts in N(1)-(4-substituted phenyl)-3-cyano-4,6-dimethyl-2-pyridones

2008 ◽  
Vol 73 (5) ◽  
pp. 513-524 ◽  
Author(s):  
Aleksandar Marinkovic ◽  
Natasa Valentic ◽  
Dusan Mijin ◽  
Gordana Uscumlic ◽  
Bratislav Jovanovic
Keyword(s):  
Correlation Analysis ◽  
Dimethyl Sulfoxide ◽  
1H Nmr ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Nmr Chemical Shifts ◽  
Resonance Effects ◽  
Non Linear ◽  
Linear Resonance ◽  
Mode Of Transmission

The 13C- and 1H-NMR chemical shifts of thirteen N(1)-(4-substituted phenyl)-3-cyano-4,6-dimethyl-2-pyridones were measured in deuterated dimethyl sulfoxide (DMSO-d6). The correlation analysis for the substituent-induced chemical shifts (SCS) with ?p, inductive (?I) and different scale of resonance (?R) parameters were performed using the SSP (single substituent parameter), DSP (dual substituent parameter) and DSP-NLR (dual substituent parameter-non-linear resonance) methods. The results of the calculations concerning the polar and resonance effects satisfactorily describe the substituent effects at the carbon atoms of interest. The mode of transmission of the substituent effects, both inductive and resonance, in relation to the geometry of the investigated pyridones is discussed.

Relativistic and Dynamic effects are needed to correctly model the 1H NMR Chemical Shifts of an Iridium Polyhydride Cluster

2020 ◽  
Author(s):  
Abril C. Castro ◽  
David Balcells ◽  
Michal Repisky ◽  
Trygve Helgaker ◽  
Michele Cascella
Keyword(s):  
1H Nmr ◽  
Chemical Shifts ◽  
Dynamic Effects ◽  
Nmr Chemical Shifts
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