Stereoselective Assembly of Gigantic Chiral Molybdenum Blue Wheels Using Lanthanide ions and Amino Acids

April 9, 2019

Title

Stereoselective Assembly of Gigantic Chiral Molybdenum Blue Wheels Using Lanthanide ions and Amino Acids

Author

Weimin Xuan, Robert Pow, Nancy watfa, Qi Zheng, Andrew J. Surman, De-Liang Long, Leroy Cronin

Year

2018

Journal

JACS

Abstract

The synthesis of chiral polyoxometalates (POMs) is a challenge because of the difficulty to induce the formation of intrin-sically chiral metal-oxo frameworks. Herein we report the stereoselective synthesis of a series of gigantic chiral Mo Blue (MB) POM clusters 1-5 that form by exploiting the synergy between coordinating lanthanides ions as symmetry breakers to produce MBs with chiral frameworks decorated with amino acids ligands; these promote the selective formation of en-antiopure MBs. All the compounds share the same framework archetype, based on {Mo124Ce4}, which forms an intrinsical-ly chiral or  configurations controlled by the configurations of functionalized chiral amino acids. The chirality and stability of 1-5 in solution are confirmed by CD, 1H NMR and Electrospray Ion Mobility-Mass Spectrometry (ESI-IMS-MS) study. In addition, the framework of the {Mo124Ce4} MB not only behaves as host, able to trap a chiral {Mo8} cluster that is not accessible by traditional synthesis, but also exhibits an enzyme-like selective oxidation of tryptophan to kynurenine in-situ. This work demonstrates the potential and applicability of our synthetic strategy produce gigantic chiral POM clusters capable of host-guest chemistry and selective synthetic transformations.

Instrument

J-710

Keywords

Circular dichroism, Ligand binding, Coordination chemistry, Inorganic chemistry