Publication

Article Metrics

Citations


Online attention

Catalysis of an aldol condensation using a coordination cage

DOI: 10.3390/chemistry2010004 DOI Help

Authors: Cristina Mozaceanu (University of Warwick) , Christopher G. P. Taylor (University of Warwick) , Jerico R. Piper (University of Warwick) , Stephen P. Argent (University of Warwick) , Michael D. Ward (University of Warwick)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry , VOL 2 , PAGES 22 - 32

State: Published (Approved)
Published: January 2020
Diamond Proposal Number(s): 19876

Open Access Open Access

Abstract: The aldol condensation of indane-1,3-dione (ID) to give ‘bindone’ in water is catalysed by an M8L12 cubic coordination cage (Hw). The absolute rate of reaction is slow under weakly acidic conditions (pH 3–4), but in the absence of a catalyst it is undetectable. In water, the binding constant of ID in the cavity of Hw is ca. 2.4(±1.2) × 103 M−1, giving a ∆G for the binding of −19.3(±1.2) kJ mol−1. The crystal structure of the complex revealed the presence of two molecules of the guest ID stacked inside the cavity, giving a packing coefficient of 74% as well as another molecule hydrogen-bonded to the cage’s exterior surface. We suggest that the catalysis occurs due to the stabilisation of the enolate anion of ID by the 16+ surface of the cage, which also attracts molecules of neutral ID to the surface because of its hydrophobicity. The cage, therefore, brings together neutral ID and its enolate anion via two different interactions to catalyse the reaction, which—as the control experiments show—occurs at the exterior surface of the cage and not inside the cage cavity.

Journal Keywords: host–guest chemistry; coordination cage; catalysis; crystal structure; supramolecular chemistry

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 04/02/2020 10:55

Discipline Tags:

Catalysis Organic Chemistry Physical Chemistry Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)