title: Insight into Lewis acid catalysis with alkaline-earth MOFs: the role of polyhedral symmetry distortions.
abstract: We propose a multidisciplinary approach to face the interpretation of heterogeneous catalysis with alkaline-earth metal-organic frameworks (MOFs). Their oxygen-based polyhedra, which do not exhibit regular geometries, do act as very active Lewis acid sites. Four novel alkaline-earth MOFs that belong to three different structural types-Mg-AEPF-11, Mg-APF-12, Ca-AEPF-13 and Sr-APF-13-are reported, together with their net topologies, and a study of the symmetry distortions around the alkaline-earth metal polyhedra by using a continuous shape mapping (CShM) description. These MOFs are good catalysts in the selective hydrogenation of styrene. Even more, Sr-AEPF-13 shows the best conversions ever published with alkaline-earth MOFs for the hydrogenation of activated alkenes under mild conditions. A combination of crystallographic and topological analysis and theoretical calculations, together with experimental catalytic results, has been applied to understand the catalytic activity of these four novel alkaline-earth MOFs. This work demonstrates that the presence of symmetry-distorted alkaline-earth polyhedra gives rise to highly catalytic-active MOFs in the hydrogenation of activated alkenes.
authors.affiliation: Department of New Architectures in Materials Chemistry, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) c/Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid (Spain), Fax: (+34) 91-372-0623; Current address: Department of Materials and Environmental Chemistry, Stockholm University, Arrhenius Laboratory, Svante Arrhenius väg 16C, 106 91 Stockholm (Sweden).
authors.forename: Ana E
authors.initials: AE
authors.lastname: Platero-Prats
authors.forename: Natalia
authors.initials: N
authors.lastname: Snejko
authors.forename: Marta
authors.initials: M
authors.lastname: Iglesias
authors.forename: Angeles
authors.initials: A
authors.lastname: Monge
authors.forename: Enrique
authors.initials: E
authors.lastname: Gutiérrez-Puebla
keywords: alkaline-earth metals; green catalysts; hydrogenation; metal-organic frameworks; symmetry distortions; topochemistry