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Detecting Hydrogen Bonding by NMR Relaxation of the Acceptor Nuclei
Author(s) -
Bagno Alessandro,
Gerard Sébastien,
Kevelam Jan,
Menna Enzo,
Scorrano Gianfranco
Publication year - 2000
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20000818)6:16<2915::aid-chem2915>3.0.co;2-o
Subject(s) - acceptor , chemistry , hydrogen bond , relaxation (psychology) , molecule , pyridine , ab initio , electric field gradient , hydrogen , anisotropy , electric field , ab initio quantum chemistry methods , phenol , photochemistry , computational chemistry , crystallography , organic chemistry , psychology , social psychology , physics , quantum mechanics , condensed matter physics
The formation of hydrogen bonds (HB) between phenol or N ‐methyltrifluoroacetamide and several acceptors (pyridine, carbonyl compounds, nitriles, amides) in CCl 4 or CHCl 3 been investigated through the analysis of NMR relaxation times ( T 1 ) of the heteronuclei ( 14 N and 17 O) directly involved in the HB interaction. Thus, a comparison is made between such T 1 values (corrected for changes in molecular dynamics and motional anisotropy) and electric field gradients calculated by ab initio methods for the acceptor molecules, both isolated and in 1:1 or 2:1 hydrogen‐bonded complexes. When other effects are properly accounted for, there is a good agreement between theoretical and experimental electric field gradient (efg) changes. The noticeable difference found between CCl 4 or CHCl 3 as solvents is discussed in relation to the presence of phenol oligomers, and the non‐negligible HB donor power of CHCl 3 .