A Flexible Photoactive Titanium Metal-Organic Framework Based on a [Ti(IV)3(μ3-O)(O)2(COO)6] Cluster

Bart Bueken; Frederik Vermoortele; Danny E P Vanpoucke; Helge Reinsch; Chih-Chin Tsou; Pieterjan Valvekens; Trees De Baerdemaeker; Rob Ameloot; Christine E A Kirschhock; Veronique Van Speybroeck; James M Mayer; Dirk De Vos

doi:10.1002/anie.201505512

A Flexible Photoactive Titanium Metal-Organic Framework Based on a [Ti(IV)3(μ3-O)(O)2(COO)6] Cluster

Angew Chem Int Ed Engl. 2015 Nov 16;54(47):13912-7. doi: 10.1002/anie.201505512. Epub 2015 Sep 25.

Affiliations

¹ Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, p.o. box 2461, 3001 Leuven (Belgium).
² Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium).
³ Department of Chemistry, Yale University, 225 Prospect Street, p.o. box 208107, New Haven, CT 06511 (USA).
⁴ Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, p.o. box 2461, 3001 Leuven (Belgium). dirk.devos@biw.kuleuven.be.

PMID: 26404186
DOI: 10.1002/anie.201505512

Abstract

The synthesis of titanium-carboxylate metal-organic frameworks (MOFs) is hampered by the high reactivity of the commonly employed alkoxide precursors. Herein, we present an innovative approach to titanium-based MOFs by the use of titanocene dichloride to synthesize COK-69, the first breathing Ti MOF, which is built up from trans-1,4-cyclohexanedicarboxylate linkers and an unprecedented [Ti(IV)3(μ3-O)(O)2(COO)6] cluster. The photoactive properties of COK-69 were investigated in depth by proton-coupled electron-transfer experiments, which revealed that up to one Ti(IV) center per cluster can be photoreduced to Ti(III) while preserving the structural integrity of the framework. The electronic structure of COK-69 was determined by molecular modeling, and a band gap of 3.77 eV was found.

Keywords: metal-organic frameworks; metallocenes; molecular modeling; photochemistry; titanium.

Publication types

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