Spontaneous Resolution of an Electron-Deficient Tetrahedral Fe4L4 cage

Pia Bonakdarzadeh; Fangfang Pan; Elina Kalenius; Ondřej Jurček; Kari Rissanen

doi:10.1002/anie.201507295

Spontaneous Resolution of an Electron-Deficient Tetrahedral Fe4L4 cage

Angew Chem Int Ed Engl. 2015 Dec 1;54(49):14890-3. doi: 10.1002/anie.201507295. Epub 2015 Oct 12.

Authors

Pia Bonakdarzadeh¹, Fangfang Pan¹, Elina Kalenius¹, Ondřej Jurček¹, Kari Rissanen²

Affiliations

¹ Department of Chemistry, NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland).
² Department of Chemistry, NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland). kari.t.rissanen@jyu.fi.

PMID: 26457686
DOI: 10.1002/anie.201507295

Abstract

A highly electron-deficient C3-symmetric tris(bipyridyl) ligand was prepared in four steps and used for the coordination of Fe(OTf)2, thereby resulting in the homochiral assembly of a new family of robust tetrahedral M4L4 cages. This homochiral T-symmetric cage containing a relatively large cavity of 330 Å(3) is capable of encapsulating an anionic guest, as was determined by mass spectrometry, (19)F NMR spectroscopy, and finally shown from its crystal structure. Moreover, crystallization of the cage from CH3CN led to crystals containing both (ΔΔΔΔ and ΛΛΛΛ) enantiomers, while crystallization from CH3 OH resulted in crystals containing only the right-handed (ΔΔΔΔ) cage. The difference in the crystal packing of the two crystal structures is discussed and a feasible explanation for the unique phenomenon among supramolecular cages--spontaneous resolution--is given.

Keywords: X-ray crystallography; cage complexes; chirality; metallosupramolecular chemistry; spontaneous resolution.

Publication types

Research Support, Non-U.S. Gov't