Porous barium-organic frameworks with highly efficient catalytic capacity and fluorescence sensing abilityElectronic supplementary information (ESI) available: Experimental details, TGA, PXRD and the solid-state luminescence emission spectra of 1 and 2, and additional figures. CCDC 981821-981823. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ta03680a

The current study describes the first barium-organic framework with permanent porosity, efficient catalytic capacity, and highly selective luminescence sensing of DMSO molecules and metal ions. Single-crystal-to-single-crystal transformations (from complex 1 to complexes 2 and 3 ) were used to thermally generate coordinatively unsaturated metal sites (CUSs) as catalytically active sites (CASs). Complex 3 exhibits efficient catalytic capacity for the cyanosilylation of aldehydes and ketones, and the cycloaddition of CO 2 and epoxides. To the best of our knowledge, complex 3 keeps a record among the MOF-based catalysts for the cyanosilylation of aldehydes and ketones. The generation of Ba 2+ CUSs with high catalytic activity in a SCSC fashion is responsible for the excellent properties of 3 , which is further confirmed by the theoretical calculation. Besides, complex 2 can highly sense DMSO molecules through fluorescence enhancement. Through single-crystal-to-single-crystal transformation, highly active Ba 2+ open metal sites are achieved in porous MOFs, which exhibit efficient catalytic capacity for the cyanosilylation of aldehydes and ketones and show excellent fluorescence sensing of DMSO molecules.