Student Poster Presentation # 5 ( Session 1 )
Highly Efficient Recycle of Water Soluble NHC-Ru Catalyst via Host- Guest Interaction
Student Poster Presentation # 5 ( Session 1 )
Highly Efficient Recycle of Water Soluble NHC-Ru Catalyst via Host- Guest Interaction
Cheoljae Kim and Hoyong Chung Department of Chemical and Biomedical Engineering , Florida State University
Abstract
Host-guest interaction is one of the defining concepts of supramolecular chemistry which describes an idea of molecular recognition and interactions through non-covalent bonding between two or more molecules or ions . Based on the specific recognition of host molecules towards guest molecules , host-guest chemistry has been widely studied for drug carriers , dye encapsulation , nanoreactors , recovery of catalysts , and etc . Cyclodextrin ( CD ) is one of a well-known host molecule , and its hydrophobic cavity provides a strong binding interaction with azo benzenes and adamantyl group via van der Waals force in water solution . Using this property , we have newly developed a highly recoverable Hoveyda-Grubbs 2 nd generation catalyst bearing extended ethylene glycols and adamantyl group on NHC ligand . In particular , extended ethylene glycol group provides a highly water soluble property for a homogenous catalytic reaction in water as well as a recovery of catalysts from organic solution by extraction with water . The adamantyl group combines with β- CD in aqueous solution , and this host-guest complex leads an efficient heterogeneous recovery of entire ruthenium catalyst after homogeneous reaction . The new recoverable NHC ligand will be extended to other transition metal catalysis ( Pd , Cu ), organocatalysis ( ring-opening polymerization of lacides ), flat surface modification , and medicinal application ( anti-cancer agent , anti-infection agent ).
Figure 1 . Our Hoveyda-Grubbs 2 nd generation catalyst
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