Determination of Stretching Frequencies by Isotopic Substitution Using Infrared Spectroscopy: An Upper-Level Undergraduate Experiment for an In-Person or Online Laboratory
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Sarah E. Shaner [1] ; Kari L. Stone [2]
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[1] Missouri State University
Missouri State University
Township of Springfield, Estados Unidos
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[2] Lewis University
Lewis University
Township of Du Page, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 100, Nº 6, 2023, págs. 2347-2352
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
A Fourier transform infrared (FTIR) experiment appropriate for an upper-level undergraduate laboratory such as chemical instrumentation is described. Students collect FTIR spectra of four protio-solvents and their deuterated analogues. In addition to qualitatively observing C–H and O–H peaks shift to lower energy upon deuteration, students apply a simple harmonic oscillator model to predict the magnitude of the shifts and gain an understanding of the relationship between reduced mass and vibrational frequencies. Vibrational calculations are then performed to corroborate the experimental results and allow students to visualize the normal modes involved via animations of the vibrations. This experiment is suitable to be used as either an in-person or online laboratory.
