Date of Award
The hydrogen-bonded complex of formic acid and pyridine has been characterized for the first time through isolation in argon matrices at 16 K, both via traditional matrix isolation experiments and by soft landing of formic acid on poly(4-vinylpyridine) (PVP). The formation of the formic acid-PVP complex was confirmed by the distinct red shifts of both the O-H and C=O stretching modes (~400 cm−1 and ~20 cm−1, respectively) and the blue shift of the C-O stretching mode (~130 cm−1) in the infrared spectrum. The shifts indicative of hydrogen bonding are similar in this soft landing experiment, and this represents a novel example of the characterization of hydrogen bonding in polymers through Fourier transform infrared absorption spectroscopy. These results were analyzed by direct comparison to a standard matrix isolation experiment with pyridine and formic acid. To support and confirm these experimental results, density functional theory calculations were employed to obtain an optimized geometry, theoretical infrared absorption bands, and binding energies for pyridine and PVP in complexes with formic acid. Values of 10.9 and 11.3 kcal/mol were obtained for the binding energy for a pyridine-formic acid bond and PVP-formic acid bond, respectively.
Rodgers, Jeffrey Michael, "The Pyridine-Formic Acid Interaction: A Matrix Isolation and Polymer Soft Landing Study" (2010). Dickinson College Honors Theses. Paper 68.