Localization of Guest Molecules in Nanopores by Pulsed EPR Spectroscopy

The Journal of Physical Chemistry C. 2018, 122(10), pp. 5376-5384. ISSN 1932-7447. eISSN 1932-7455. Available under: doi: 10.1021/acs.jpcc.7b10758

Zusammenfassung

The localization of guest molecules at the molecular scale in mesoporous host materials is crucial for applications in heterogeneous catalysis, chromatography, drug delivery, and in different biomedical applications. Here, we present for the first time the precise localization of different guest molecules inside the mesoporous organosilica material UKON2a with a pore size of 6 nm. We exploited paramagnetic probe molecules 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) and 4-carboxy-TEMPO in combination with a deuteration strategy. Applying a complementary set of different pulsed electron paramagnetic resonance methods, we obtained information about the dimensionality of the spatial distribution and local concentration via double electron–electron resonance experiments, orientation of the guest molecules with respect to the pore walls via electron spin echo envelope modulation spectroscopy, and about the distance between guest molecules and pore walls via electron nuclear double resonance spectroscopy. This allowed localizing the guest molecules and shows that their spatial distribution in nanopores strongly depends on their polarity.

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PIVTSOV, Andrey, Martin WESSIG, Viktoriia KLOVAK, Sebastian POLARZ, Malte DRESCHER, 2018. Localization of Guest Molecules in Nanopores by Pulsed EPR Spectroscopy. In: The Journal of Physical Chemistry C. 2018, 122(10), pp. 5376-5384. ISSN 1932-7447. eISSN 1932-7455. Available under: doi: 10.1021/acs.jpcc.7b10758

BibTex

@article{Pivtsov2018-03-02Local-41837,
  year={2018},
  doi={10.1021/acs.jpcc.7b10758},
  title={Localization of Guest Molecules in Nanopores by Pulsed EPR Spectroscopy},
  number={10},
  volume={122},
  issn={1932-7447},
  journal={The Journal of Physical Chemistry C},
  pages={5376--5384},
  author={Pivtsov, Andrey and Wessig, Martin and Klovak, Viktoriia and Polarz, Sebastian and Drescher, Malte}
}

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