Investigation of solute-solvent interactions in phenol compounds: accurate ab initio calculations of solvent effects on 1H NMR chemical shifts.
Org Biomol Chem
; 11(42): 7400-11, 2013 Nov 14.
Article
in En
| MEDLINE
| ID: mdl-24071830
ABSTRACT
Accurate (1)H chemical shifts of the -OH groups of polyphenol compounds can be calculated, compared to experimental values, using a combination of DFT, polarizable continuum model (PCM) and discrete solute-solvent hydrogen bond interactions. The study focuses on three molecular solutes phenol, 4-methylcatechol and the natural product genkwanin in DMSO, acetone, acetonitrile, and chloroform. Excellent linear correlation between experimental and computed chemical shifts (with the GIAO method at the DFT/B3LYP/6-311++G(2d,p) level) was obtained with minimization of the solvation complexes at the DFT/B3LYP/6-31+G(d) and DFT/B3LYP/6-311++G(d,p) level of theory with a correlation coefficient of 0.991. The use of the DFT/B3LYP/6-31+G(d) level of theory for minimization could provide an excellent means for the accurate prediction of the experimental OH chemical shift range of over 8 ppm due to (i) strong intramolecular and solute-solvent intermolecular hydrogen bonds, (ii) flip-flop intramolecular hydrogen bonds, and (iii) conformational effects of substituents of genkwanin. The combined use of ab initio calculations and experimental (1)H chemical shifts of phenol -OH groups provides a method of primary interest in order to obtain detailed structural, conformation and electronic description of solute-solvent interactions at a molecular level.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
Language:
En
Journal:
Org Biomol Chem
Journal subject:
BIOQUIMICA
/
QUIMICA
Year:
2013
Document type:
Article