Identification and quantification of cis and trans isomers in aminophenyl double‐decker silsesquioxanes using 1H–29Si gHMBC NMR |
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Authors: | BW Schoen D Holmes A Lee |
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Institution: | 1. Chemical Engineering and Materials Science, Michigan State University, , East Lansing, MI, United States;2. Chemistry, Michigan State University, , East Lansing, MI, United States |
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Abstract: | Cis and trans isomers of a series of double‐decker silsesquioxanes (DDSQ) were characterized by two‐dimensional NMR techniques. The 1H NMR spectra of these species have not previously been assigned to a degree that allows for quantification. Thus, 1H–29Si HMBC correlations were applied to facilitate 1H spectral assignment and also to confirm previous 29Si assignments for this class of silsesquioxanes. With the ability to identify all the pertinent resonances of the 1H NMR spectrum, 29Si 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. |
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Keywords: | NMR 1H 29Si 2D NMR 1H– 29Si HMBC double‐decker silsesquioxanes cis/trans isomers |
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