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Libration of phenyl groups detected by VT‐SSNMR : Comparison with X‐ray crystallography
Author(s) -
Nieto Carla I.,
Cabildo Pilar,
García M. Ángeles,
Claramunt Rosa M.,
Elguero José,
Alkorta Ibon
Publication year - 2018
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.4754
Subject(s) - chemistry , crystallography , libration (molecule) , x ray , x ray crystallography , stereochemistry , diffraction , geometry , physics , point (geometry) , mathematics , optics , quantum mechanics
The X‐ray crystal structure of 2‐benzyl‐1 H ‐benzimidazole, 2BnBzIm , was determined at 293 K showing no dynamic phenomena (disorder) of any class. On the other hand, some 13 C NMR signals were absent in the CPMAS spectrum (100 MHz, 300 K). We decided to carry out variable‐temperature SSNMR and discovered that the missing signals are ortho and meta carbons of the phenyl ring of the benzyl group. Line‐shape analysis and the Eyring equation were used to determine the barrier, which was compared with the calculated DFT for the gas phase that it is much lower.