Cyclohexanohemicucurbit[8]uril Inclusion Complexes With Heterocycles and Selective Extraction of Sulfur Compounds From Water

Tatsiana Shalima; Kamini A Mishra; Sandra Kaabel; Lukas Ustrnul; Simona Bartkova; Kaia Tõnsuaadu; Ivo Heinmaa; Riina Aav

doi:10.3389/fchem.2021.786746

Cyclohexanohemicucurbit[8]uril Inclusion Complexes With Heterocycles and Selective Extraction of Sulfur Compounds From Water

Front Chem. 2021 Dec 3:9:786746. doi: 10.3389/fchem.2021.786746. eCollection 2021.

Authors

Tatsiana Shalima¹, Kamini A Mishra¹, Sandra Kaabel², Lukas Ustrnul¹, Simona Bartkova¹, Kaia Tõnsuaadu³, Ivo Heinmaa⁴, Riina Aav¹

Affiliations

¹ Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia.
² Department of Chemistry, McGill University, Montreal, QC, Canada.
³ Laboratory of Inorganic Materials, School of Engineering, Institute of Materials and Environmental Technology, Tallinn University of Technology, Tallinn, Estonia.
⁴ Laboratory of Chemical Physics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.

Abstract

Solid-phase extraction that utilizes selective macrocyclic receptors can serve as a useful tool for removal of chemical wastes. Hemicucurbiturils are known to form inclusion complexes with suitably sized anions; however, their use in selective binding of non-charged species is still very limited. In this study, we found that cyclohexanohemicucurbit[8]uril encapsulates five- and six-membered sulfur- and oxygen-containing unsubstituted heterocycles, which is investigated by single-crystal X-ray diffraction, NMR spectroscopy, isothermal titration calorimetry, and thermogravimetry. The macrocycle acts as a promising selective sorption material for the extraction of sulfur heterocycles, such as 1,3-dithiolane and α-lipoic acid, from water.

Keywords: Hemicucurbituril; MAS NMR; SC-XRD; heterocycles; inclusion complex; lipoic acid; solid-phase extraction; sorbent recycling.