Abstract
In a leap toward anion separation that uses only energy input for binding and release cycles, we report herein a new class of photoswitchable anion receptors featuring a diiminoguanidinium functionality that displays a change of more than five orders of magnitude in switched-off binding strength towards sulfate, a representative oxyanion, upon photoirradiation with UV light. The (E,E)-2-pyridyl-diiminoguanidinium cation, synthesized as the triflate salt, binds sulfate with extraordinary strength in [D6]DMSO owing to its bidentate guanidinium hydrogen bonding, which can chelate the O−S−O edge of sulfate. Upon photoisomerization to the Z,Z isomer, the anion-binding site is essentially shut off by intramolecular hydrogen bonds to the 2-pyridyl substituents, as shown by anion-binding titrations, theoretical calculations, and X-ray structural analysis. This approach will allow the development of advanced anion-separation cycles that use only energy input and generate no chemical waste, and thus address challenging chemical separation problems in a more sustainable way.
| Original language | English |
|---|---|
| Article number | e202200719 |
| Journal | Chemistry - A European Journal |
| Volume | 28 |
| Issue number | 26 |
| DOIs | |
| State | Published - May 6 2022 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory and the National Energy Research Scientific Computing Center (NERSC), which are supported by the Office of Science of the U.S. Department of Energy under contracts no. DE‐AC05‐00OR22725 and no. DE‐AC02‐05CH11231, respectively. We would like to acknowledge Drs. Peter Bonnesen, Benjamin Doughty, and Yingzhong Ma for fruitful discussions and advice on experimental design, and Drs. Fabian Bohle and Stefan Grimme at Universität Bonn for providing their code and guidance on the H NMR calculations. The manuscript was produced by UT‐Battelle, LLC under contract no. DE‐AC05‐00OR22725 with the U.S. Department of Energy. The publisher acknowledges the U.S. Government license to provide public access under the DOE Public Access Plan ( http://energy.gov/downloads/doe‐public‐access‐plan ). 1 This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory and the National Energy Research Scientific Computing Center (NERSC), which are supported by the Office of Science of the U.S. Department of Energy under contracts no. DE-AC05-00OR22725 and no. DE-AC02-05CH11231, respectively. We would like to acknowledge Drs. Peter Bonnesen, Benjamin Doughty, and Yingzhong Ma for fruitful discussions and advice on experimental design, and Drs. Fabian Bohle and Stefan Grimme at Universit?t Bonn for providing their code and guidance on the 1H NMR calculations. The manuscript was produced by UT-Battelle, LLC under contract no. DE-AC05-00OR22725 with the U.S. Department of Energy. The publisher acknowledges the U.S. Government license to provide public access under the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
| Funders | Funder number |
|---|---|
| CADES | |
| DOE Public Access Plan | |
| Data Environment for Science | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | DE‐AC02‐05CH11231, DE‐AC05‐00OR22725 |
| Chemical Sciences, Geosciences, and Biosciences Division |
Keywords
- anions
- guanidines
- photoswitches
- separations
- sulfate
