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Identification and quantification of cis and trans isomers in aminophenyl double‐decker silsesquioxanes using 1 H– 29 Si gHMBC NMR
Author(s) -
Schoen B.W.,
Holmes D.,
Lee A.
Publication year - 2013
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.3962
Subject(s) - chemistry , cis–trans isomerism , nmr spectra database , carbon 13 nmr , nuclear magnetic resonance spectroscopy , characterization (materials science) , spectral line , chemical shift , stereochemistry , analytical chemistry (journal) , organic chemistry , nanotechnology , physics , materials science , astronomy
Cis and trans isomers of a series of double‐decker silsesquioxanes (DDSQ) were characterized by two‐dimensional NMR techniques. The 1 H NMR spectra of these species have not previously been assigned to a degree that allows for quantification. Thus, 1 H– 29 Si HMBC correlations were applied to facilitate 1 H spectral assignment and also to confirm previous 29 Si assignments for this class of silsesquioxanes. With the ability to identify all the pertinent resonances of the 1 H NMR spectrum, 29 Si NMR is no longer required for quantification and required only for characterization. This not only saves time and material but also provides a more accurate quantification, thus allowing for the ratio of cis and trans isomers present in each compound to be determined. A more accurate measure of the cis / trans ratio enables the investigation of its influence on the physical and chemical properties of DDSQ nanostructured materials. Copyright © 2013 John Wiley & Sons, Ltd.