Cucurbit[8]uril forms tight inclusion complexes with cationic triamantanes

King, David; Šumanovac, Tatjana; Murkli, Steven; Schreiner, Peter R.; Šekutor, Marina; Isaacs, Lyle (2023) Cucurbit[8]uril forms tight inclusion complexes with cationic triamantanes. New Journal of Chemistry, 47 (11). pp. 5338-5346. ISSN 1144-0546

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Official URL: http://doi.org/10.1039/d3nj00156c

Abstract

We report the synthesis of quaternary (di)cationic triamantane derivatives G1 and G3 by the permethylation of the corresponding primary ammonium ions G2 and G4. The complexation behaviors of G1 – G4 toward CB[7] and CB[8] were examined by 1H NMR spectroscopy, which reveals that CB[8] is capable of fully encapsulating G1 – G4 whereas CB[7] forms inclusions complexes with G1, G2, and G4 but cannot fully encapsulate the central hydrophobic core of bis-quaternary ammonium ion G3. The geometry of the CB[n]•guest complexes were determined by analyzing the complexation induced changes in chemical shifts and were further confirmed by molecular modelling using the Conformer-Rotamer Ensemble Sampling Tool (CREST) based on the GFN methods. Finally, the complexation thermodynamics were determined by a combination of 1H NMR competition experiments, direct isothermal titration calorimetry (ITC) measurements, and competitive ITC titrations using a tight binding ternary complex as competitor.

Item Type:

Article

Uncontrolled Keywords:

Diamondoids ; Host-guest complexes ; Cucurbit[n]urils ; Triamantane ; Titrations

Subjects:

NATURAL SCIENCES > Chemistry > Physical Chemistry
NATURAL SCIENCES > Chemistry > Organic Chemistry

Divisions:

Division of Organic Chemistry and Biochemistry

Projects: