NMR measurements coupled with quantum mechanical …核磁共振测量与量子力学.pptVIP

nitrotoluidines 5-methyl-2-nitroaniline Chemical shifts C1 144.8 C2 130.0 C3 125.7 C4 118.5 C5 147.2 C6 118.2 proton coupled 13C spectra other donor/acceptors practical issues Students work in pairs and need to find time outside of the regularly scheduled lab period to collect spectra not all compounds dissolve well in CDCl3 – other solvents are sometimes used (acetone, acetonitrile, DMSO) or else heating to get dilute solutions. practical issues access to Gaussian 09 is made possible through a linux server running apache. http://webMO.net Conclusions Molecular orbital calculations are useful in interpreting and predicting NMR spectra and as such, they are useful for students to use as part of an experimental lab project. Conformational analysis is needed for more flexible molecules but this adds additional value by forcing students to think about structures other than a flat line drawing. Advanced NMR techniques such as proton coupled 13C spectra and 2D-COSY can be introduced by giving students the task of assigning peaks in an observed 13C spectrum and asking them to construct a proof. Future work adding in the use of different solvents modeling specific solvent-solute interactions calculating and comparing JJ coupling Acknowledgments Fordham University Research Council NSF Instrumentation Grant Gaussian, Inc. MolecVUE Project ACS National Spring Meeting: Anaheim 2011 CHED 24 James B. Foresman, York College of PA Donald D. Clarke, Fordham University Collaboration Donald Clarke Department of Chemistry Fordham University Bronx, New York, 10458 James Foresman Department of Physical Sciences York College of Pennsylvania York, PA 17405 Collaboration 300 MHz Bruker FT-NMR Gaussian 09 Electronic Structure Modeling Theory and Experiment Modeling of mechanisms and thermochemistry in support of synthesis Theory and Experiment Interpretation of Vibrational CD Spectra in assignment of Absolute Configurations for Chiral molecules Chiral-IR Theory and Exp