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H NMR spectra of substituted phenyl succinamic acids: A case study of deceptive simplicity
Author(s) -
Risley John M,
Young Amber M,
Kastanis John P,
Stanziale Jennifer A,
Zohby Rana
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.568.5
Subject(s) - nmr spectra database , spectral line , chemistry , molecule , proton nmr , ethylene , computational chemistry , stereochemistry , organic chemistry , catalysis , physics , astronomy
NMR is an important technique used to establish purity of molecules; it is particularly important for molecules with pharmaceutical activity. The spectra for compounds containing para ‐substituted phenyl rings and 1,2‐disubstituted ethylene groups often are deceptively simple that are analyzed in first‐order terms when the spectra are second‐order. The 1 H NMR spectra for para ‐substituted phenyl succinamic acids are an example of molecules with deceptively simple spectra that have been analyzed in first‐order terms when, in fact, the spectra contain two sets of second‐order spectra. Using WINDNMR spectra simulation program, the 1 H NMR spectra for a series of para ‐substituted phenyl succinamic acids have been analyzed. The two sets of second‐order spectra are both AA′BB′ with very different values for the coupling constants. The differences in the second‐order spectra for the ethylene group have been analyzed in ortho‐ and meta ‐substituted phenyl succinamic acids. Funding was provided in part by UNC‐Charlotte and a grant from the NSF.