Metal

Symmetry breaking

Quantum mechanics

Catalysis

Enantioselective synthesis

Enantiomer

Racemization

Chelation

Axial chirality

Crystal structure

Nambu–Jona-Lasinio model

Inorganic chemistry

Dissociation (chemistry)

Stereochemistry

Combinatorial chemistry

Physics

Organic chemistry

Crystallization

Kinetic resolution

Racemic mixture

Crystallography

Chirality (physics)

Chemistry

Octahedron

Chiral symmetry breaking

Epimer

Journal of the American Chemical Society

The stereochemistry of chiral-at-metal complexes is much more abundant, albeit complicated, than chiral-at-carbon compounds, but how to make use of stereolabile metal-centers remains a formidable challenge due to the highly versatile coordination geometry of metal ions and racemization/epimerization problem. We demonstrate herein a stepwise assembly of configurationally stable [Pd6(FeL3)8]28+ (Δ/Λ-MOCs-42) homochiral octahedral cages from unstable D3-symmetry tris-chelate-Fe type metalloligands via strong face-directed stereochemical coupling and facile chiral-induced resolution processes based on stereodifferentiating host–guest dynamics. Kinetic studies reveal that the dissociation rate of MOC-42 cages is 100-fold slower than that of Fe-metalloligands and the racemization is effectively inhibited, making the cages retain their chirality over extended periods of time (>5 months) at room temperature. Recyclable enantioseparation of atropisomeric compounds has been successfully achieved, giving up to 88% ee.

Design and Enantioresolution of Homochiral Fe(II)–Pd(II) Coordination Cages from Stereolabile Metalloligands: Stereochemical Stability and Enantioselective Separation