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Layer selection effect on solid state 13C and 15N chemical shifts calculation using ONIOM approach

Shaghaghi, H ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ssnmr.2013.01.002
  3. Publisher: 2013
  4. Abstract:
  5. Solid state 13C and 15N chemical shifts of uracil and imidazole have been calculated using a 2-layer ONIOM approach at 32 levels of theory. The effect of electron correlation between two layers has been investigated by choosing two different kinds of layer selection. Factorial design has been applied as a multivariate technique to analyze the effect of wave function and layer selection on solid state 13C and 15N chemical shifts calculations. PBEPBE/6-311+G(d,p) was recommended as an optimally selected level of theory for high layer in both models. It is illustrated that considering the electron correlation of two layers of ONIOM models is important factor to calculate solid state 15N chemical shifts. The agreement between the calculated and experimental values of solid state 13C and 15N chemical shifts using ONIOM (PBEPBE/6-311+G(d,p):AM1) for both uracil and imidazole confirmed the reliability of the selected wave functions and layer selection
  6. Keywords:
  7. Oniom ; Chemical shift ; Solid state chemical shift ; Experimental values ; Factorial design ; Multivariate techniques ; Oniom approach ; Aromatic compounds ; Electron correlations ; Nuclear magnetic resonance ; Wave functions ; NMR ; Imidazole derivative ; Chemical structure ; Chemistry ; Conformation ; Methodology ; Nuclear magnetic resonance spectroscopy ; Imidazoles ; Magnetic Resonance Spectroscopy ; Models, Molecular ; Molecular Conformation ; Uracil
  8. Source: Solid State Nuclear Magnetic Resonance ; Volume 51-52 , 2013 , Pages 31-36 ; 09262040 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0926204013000155