Premium
The observed and calculated 1 H and 13 C chemical shifts of tertiary amines and their N ‐oxides
Author(s) -
Pohl Radek,
Dračínský Martin,
Slavětínská Lenka,
Buděšínský Miloš
Publication year - 2011
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2750
Subject(s) - chemistry , chemical shift , density functional theory , basis set , computational chemistry , amine gas treating , tertiary amine , perturbation theory (quantum mechanics) , nmr spectra database , carbon 13 nmr , spectral line , oxide , proton nmr , stereochemistry , organic chemistry , quantum mechanics , physics
A series of model tertiary amines were oxidized in situ in an NMR tube to amine N ‐oxides and their 1 H and 13 C NMR spectra were recorded. Next, the chemical shifts induced by oxidation (Δδ) were calculated using different GIAO methods investigating the influence of the method [Hartree‐Fock (HF), Moeller‐Plesset perturbation, density functional theory (DFT)], the functional applied in the DFT (B3LYP, BPW, OPBE, OPW91) and the basis set used [6‐31G*, 6‐311G**, 6‐311 + + G** and 6‐311 + + G(3df,3pd)]. The best results were obtained with the HF/6‐311 + + G** and OPBE/6‐311 + + G** methods. The computation/experiment comparison approach was used for the configuration prediction of chiral amine N ‐oxides—( R ) and ( S )‐agroclavine‐6‐ N ‐oxide. Copyright © 2011 John Wiley & Sons, Ltd.