title: Rare earth arenedisulfonate metal-organic frameworks: an approach toward polyhedral diversity and variety of functional compounds.
abstract: Eight 2D and 3D metal-organic framework (MOF) rare earth naphthalenedisulfonates have been obtained. The different geometry of the naphthalenedisulfonic acids used as connectors [(1,5-NDS) and (2,6-NDS)] gives rise to the three new structure types. In Ln(OH)(1,5-NDS)H2O, LnPF-1 (lanthanide polymeric framework; Ln=La, Nd, Pr, Sm and Eu), the lanthanide ion is octacoordinated. Its 3D structure is formed by (Ln2O14)-S-(Ln2O14) infinite chains, connected through complete NDS connectors. LnPF-2 (Ln=Nd), with the same empirical formula as the former, and the lanthanide in octa- and nonacoordination, owns an arrangement of sulfonate bridges and neodymium polyhedra that gives rise to a 2D structure. [Ln5(2,6-NDS)3(OH)9(H2O)4](H2O)2, LnPF-3 (Ln=Nd, Eu), demonstrates that it is possible to obtain a 3D structure with (2,6-NDS), when a greater Ln/connector ratio is employed. It is worth pointing out the existence, in this latter family of compounds, of a mu5-OH group, whose hydrogen atom is very close to one-sixth Ln atom (distance Ln...H=2.09 A). The materials, with high thermal stability, act as active and selective bifunctional heterogeneous catalysts in oxidation of linalool yielding cyclic hydroxy ethers. The absence of any 3D Nd-Nd magnetic interaction is explained due to the inner nature of 4f orbitals of Nd3+, which do not favor the magnetic exchange. The influence of the polymeric frame matrix results in a better photoluminescence efficiency for NdPF-1.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Gándara
authors.forename: Alberto
authors.initials: A
authors.lastname: García-Cortés
authors.forename: Concepción
authors.initials: C
authors.lastname: Cascales
authors.forename: Berta
authors.initials: B
authors.lastname: Gómez-Lor
authors.forename: Enrique
authors.initials: E
authors.lastname: Gutiérrez-Puebla
authors.forename: Marta
authors.initials: M
authors.lastname: Iglesias
authors.forename: Angeles
authors.initials: A
authors.lastname: Monge
authors.forename: Natalia
authors.initials: N
authors.lastname: Snejko