UV and Chemical Modifications of Polymer of Intrinsic Microporosity 1 to Develop Vibrational Spectroscopic Probes of Surface Chemistry and Porosity


This work probes host-guest interactions of nitrogen using in-situ vibrational spectroscopy, as the pore structure, pore size, and surface chemistry of a Polymer of Intrinsic Microporosity (PIM-1) are varied. N2 adsorption to PIM-1 renders the N2 infrared vibron active, establishing a weak dipole-dipole interaction. The perturbation of the N2 vibrational mode at room temperature is much stronger for PIM-1 than other porous carbon materials, implicating the C-N surface group of PIM-1 in the degree of shift in the vibrational spectra and suggesting a strong π-π stacking gas-surface interaction. No perturbation of the N2 spectra is observed for a non-porous C-N analogue (tetrafluoro-terepthalonitrile) or after conversion of the C-N group of PIM-1 to an amide. The pore size of PIM-1 is reduced via UV irradiation, leading to an increase in the shift of the Raman-active N2 perturbation.


Chemical and Biochemical Engineering


Funding for this work was provided by the U.S. Department of Energy; DOE-BES under Grant No. DE-FG02-09ER466556 and DE-SC0002157. Preparation of the paper was supported by (while AL was serving at) the National Science Foundation.

Keywords and Phrases

Adsorption; Nitrogen; Porous polymers; Spectroscopy

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Article - Journal

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© 2019 Elsevier B.V., All rights reserved.

Publication Date

01 Mar 2019