Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1409701 | Journal of Molecular Structure | 2011 | 8 Pages |
Abstract
The crystal structure of the 1:1:1 complex of trigonelline (N-methyl-3-carboxy-pyridinium, TRG) water and p-hydroxybenzoic acid, HBA, has been determined by X-ray diffraction. The crystals are monoclinic, space group P21/c. The carboxylic group of HBA is linked to the carboxylate group of TRG by the COOHâ¯OOC hydrogen bond of 2.632(2) Ã
, while the hydroxyl group interacts, as a proton-donor, with the water molecule via the O-Hâ¯O hydrogen bond of 2.639(2) Ã
. The water molecule plays a role of the double proton-donor to two TRG molecules by the O-Hâ¯OOC hydrogen bonds of 2.772(2) and 2.751(2) Ã
. This net of hydrogen bonds forms in the crystal a layer with hydrophilic internal area and hydrophobic external area. Four structures, with different order of TRG, water and HBA in the complex, have been optimized by the B3LYP/6-31G(d,p) approach. The experimental solid-state FTIR spectrum of the complex investigated have been compared with the calculated one by the B3LYP/6-31G(d,p) approach. The assignments of the 1H and 13C chemical shifts are based on the 1H-1H and 1H-13C, and HMBS experiments. The isotropic magnetic shielding constants, calculated by the GIAO/B3LYP/6-31G(d,p) approach, have been used to predict the 1H and 13C chemical shifts.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Z. Dega-Szafran, G. Dutkiewicz, Z. Kosturkiewicz, M. Szafran,