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Computation and NMR crystallography of terbutaline sulfate
Author(s) -
Harris Robin K.,
Hodgkinson Paul,
Zorin Vadim,
Dumez JeanNicolas,
ElenaHerrmann Bénédicte,
Emsley Lyndon,
Salager Elodie,
Stein Robin S.
Publication year - 2010
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.2636
Subject(s) - chemistry , chemical shift , proton , castep , crystal structure , proton nmr , carbon 13 nmr , nmr spectra database , crystallography , spectral line , computation , hydrogen bond , carbon 13 nmr satellite , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , computational chemistry , molecule , fluorine 19 nmr , stereochemistry , electronic structure , physics , algorithm , organic chemistry , quantum mechanics , astronomy , computer science
This article addresses, by means of computation and advanced experiments, one of the key challenges of NMR crystallography, namely the assignment of individual resonances to specific sites in a crystal structure. Moreover, it shows how NMR can be used for crystal structure validation. The case examined is form B of terbutaline sulfate. CPMAS 13 C and fast MAS 1 H spectra have been recorded and the peaks assigned as far as possible. Comparison of 13 C chemical shifts computed using the CASTEP program (incorporating the Gauge Including Projector Augmented Wave principle) with those obtained experimentally enable the accuracy of the two distinct single‐crystal evaluations of the structure to be compared and an error in one of these is located. The computations have substantially aided in the assignments of both 13 C and 1 H resonances, as has a series of two‐dimensional (2D) spectra (HETCOR, DQ‐CRAMPS and proton–proton spin diffusion). The 2D spectra have enabled many of the proton chemical shifts to be pinpointed. The relationships of the NMR shifts to the specific nuclear sites in the crystal structure have therefore been established for most 13 C peaks and for some 1 H signals. Emphasis is placed on the effects of hydrogen bonding on the proton chemical shifts. Copyright © 2010 John Wiley & Sons, Ltd.