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Modeling Substituent-Dependence of the Twist and Shielding in a Series of 4-Substituted N-(4-Nitrobenzylidene)anilines
- Source :
- Collection of Czechoslovak Chemical Communications. 69:1566-1576
- Publication Year :
- 2004
- Publisher :
- Institute of Organic Chemistry & Biochemistry, 2004.
-
Abstract
- A series of 15 4-substituted N-(4-nitrobenzylidene)anilines was synthesized and studied by 1H NMR spectroscopy. Their ab initio calculated geometries and the shielding as expressed by aromatic ring currents were used in correlation analysis. The geometries were fully optimized using density functional theory B3LYP/6-311G** approaches. For the determination of the ring current contribution to the shielding of azomethine hydrogens Hα was used direct ab initio calculation of the chemical shielding in a model system. Experimental chemical shift values free of these contributions were successfully correlated with increments ap of chemical shift for monosubstituted benzenes. In the same manner, the contribution of the anisotropy of C=N double bond to Hm hydrogen were calculated and values of the Hm chemical shift free of this contribution were successfully correlated with increments of chemical shift am.
- Subjects :
- Series (mathematics)
010405 organic chemistry
Substituent
General Chemistry
Nuclear magnetic resonance spectroscopy
010402 general chemistry
01 natural sciences
0104 chemical sciences
chemistry.chemical_compound
chemistry
Ab initio quantum chemistry methods
Computational chemistry
Electromagnetic shielding
Correlation analysis
Twist
Subjects
Details
- ISSN :
- 12126950 and 00100765
- Volume :
- 69
- Database :
- OpenAIRE
- Journal :
- Collection of Czechoslovak Chemical Communications
- Accession number :
- edsair.doi...........ab157b3daf8419c59bc85e3611db8046