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Updated: Mar 2, 2026

Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Active metal template synthesis of a neutral indolocarbazole-containing [2]rotaxane host system for selective
Asha Brown1, Thomas Lang, Kathleen M Mullen
1Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK. paul.beer@chem.ox.ac.uk.
Abstract:
An active metal template strategy was used to synthesise a neutral indolocarbazole containing [2]rotaxane anion host system. 1H NMR anion binding investigations reveal that the [2]rotaxane recognises a range of monoanions in acetone-d5 : D2O 95 : 5 with an unusual interlocked host selectivity for acetate and dihydrogenphosphate oxoanions over halides. The rotaxane displays an overall selectivity for the sulfate dianion, favouring a 2 : 1 host : guest binding stoichiometry at low sulfate concentration and a 1 : 1 stoichiometry in the presence of excess sulfate. Fluorescence titration demonstrates that the [2]rotaxane is also capable of sensing guest anions via significant changes in its emission spectrum.
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