Spectroscopic insight into supramolecular assemblies of boric acid derivatives and β-cyclodextrin

Artur Kasprzak; Krzysztof M Borys; Sergey Molchanov; Agnieszka Adamczyk-Woźniak

doi:10.1016/j.carbpol.2018.06.085

Spectroscopic insight into supramolecular assemblies of boric acid derivatives and β-cyclodextrin

Carbohydr Polym. 2018 Oct 15:198:294-301. doi: 10.1016/j.carbpol.2018.06.085. Epub 2018 Jun 22.

Authors

Artur Kasprzak¹, Krzysztof M Borys², Sergey Molchanov³, Agnieszka Adamczyk-Woźniak³

Affiliations

¹ Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland. Electronic address: akasprzak@ch.pw.edu.pl.
² Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland. Electronic address: kborys@ch.pw.edu.pl.
³ Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.

PMID: 30093002
DOI: 10.1016/j.carbpol.2018.06.085

Abstract

Interactions of select boric acid derivatives with β-cyclodextrin were investigated. All products were obtained employing the grinding-induced mechanochemical approach. It was found that phenylboronic acid, benzoxaborole and boric acid form non-covalent, hydrogen bonding-based systems with β-cyclodextrin, whereas catechol and pinacol esters of phenylboronic acid as well as ferroceneboronic acid form host-guest inclusion complexes. The interactions were probed using spectroscopic methods: ¹H NMR, ¹H-¹H ROESY NMR, ¹H DOSY NMR, FT-IR. Association constant values were evaluated by ¹H DOSY NMR. The highest association constant was found for boric acid (117.5 ± 2.5 M^-1), whilst the lowest for benzoxaborole (14.8 ± 0.3 M^-1). The study shows the influence of boron compound structure on the nature of the assembly formed with β-cyclodextrin, laying up the basis for future work with such supramolecular systems.

Keywords: Boric; Ferroceneboronic; Organoboron; Phenylboronic; β-Cyclodextrin.