What does that molecule look like? Using tandem mass spectrometry, computational chemistry and vibrational spectroscopy to determine molecular structure

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Dain, Ryan P.
Van Stipdonk, Michael J.

Dain, Ryan P. and Michael J. Van Stipdonk (2009). What Does That Molecule Look Like? Using Tandem Mass Spectrometry, Computational Chemistry and Vibrational Spectroscopy to Determine Molecular Structure. In Proceedings: 5th Annual Symposium: Graduate Research and Scholarly Projects. Wichita, KS: Wichita State University, p. 86-87


Scientists wanting to determine the structure of a molecule have many tools at their disposal. Tandem mass spectrometry (MS/MS) allows one to study the fragmentation pathways of molecules, examining how a molecule will fall apart when energy is added to it through a process known as collision induced dissociation (CID). By measuring the mass and abundance of these fragments, one can make determinations about the original, or parent, species. Computational chemistry allows one to model a molecule with many different structures, determining which represents the most likely one by looking at the relative energies and theoretical infrared (IR) vibrational spectra. Vibrational spectroscopy is used because each molecule, in principle, has a different IR spectrum that depends on its structure, much like a fingerprint. The theoretical IR spectra for various structures can then be compared to an experimental IR spectrum, to establish the true conformation. Therefore, using these three tools a scientist can confidently determine the structure of a molecule, and a better understanding about the innate chemistry of that molecule.

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Paper presented to the 5th Annual Symposium on Graduate Research and Scholarly Projects (GRASP) held at the Hughes Metropolitan Complex, Wichita State University, May 1, 2009.
Research completed at Department of Chemistry, Fairmount College of Liberal Arts and Sciences