Francisco F.G.Cirujano

MOFs as multifunctional catalysts: One-pot synthesis of menthol from citronellal over a bifunctional MIL-101 catalyst

A bifunctional MOF catalyst containing coordinatively unsaturated Cr(3+) sites and palladium nanoparticles (Pd@MIL-101) has been used for the cyclization of citronellal to isopulegol and for the one-pot tandem isomerization/hydrogenation of citronellal to menthol. The MOF was found to be stable under the reaction conditions used, and the results obtained indicate that the performance of this bifunctional solid catalyst is comparable with other state-of-the-art materials for the tandem reaction: Full citronellal conversion was attained over Pd@MIL-101 in 18 h, with 86% selectivity to menthols and a diastereoselectivity of 81% to the desired (-)-menthol, while up to 30 h were necessary for attaining similar values over Ir/H-beta under analogous reaction conditions.

MOFs as Multifunctional catalysts: Synthesis of secondary arylamines, quinolines, pyrroles and arylpyrrolidines over bifunctional MIL-101

Bifunctional MIL‐101 MOFs containing Lewis acid Cr3+ sites and Pd or Pt hydrogenation/reduction centers, either as isolated metal complexes or in the form of encapsulated metal nanoparticles, have shown to be highly active catalysts for the one‐pot nitroarene reduction and reductive amination of carbonyl compounds. This preparation procedure has been successfully applied to the synthesis of secondary arylamines, quinolines, pyrrols, and 3‐arylpyrrolidines. In all the cases, the MOFs have shown superior performances with respect to commercially available Pd and Pt metal catalysts under the same conditions.

CHAPTER 7:Strategies for Creating Active Sites in MOFs

This chapter presents a general overview of the main properties of MOFs that make them very appealing for applications in heterogeneous catalysis. Great efforts have been directed in the last decade to study the potential of MOFs in catalysis. We will now see what is behind this “MOF rush”. Next, we will present some general considerations that should be taken into account when planning the use of MOFs as heterogeneous catalysts, such as stability, recovery and reusability. And finally, we will review the different strategies that can be used to introduce the desired catalytic centers into the MOFs. We will show how it is possible by using these strategies to engineer the material for catalysis, and to fine tune the properties of the MOF to influence the catalytic performance.

Metal Organic Frameworks as Nanoreactors and Host Matrices for Encapsulation

Abstract Throughout this chapter, we review the work done so far on MOFs as either nanoreactors or as host-matrices for encapsulating species. The review is far from exhaustive. However, our aim is to illustrate the possibilities of these materials through examples taken from the literature. We have first outlined the advantages of MOFs as nanoreactors and encapsulation systems, we have also highlighted their weaknesses, so that readers may see both sides. The examples reported in the chapter have been roughly divided in two parts, according to the function of the MOF as either the confined space in which a chemical process takes place (nanoreactor) or as the solid support used to incorporate exogenous species through encapsulation. Concerning encapsulation, we first present a short review of the existing methods for preparing encapsulated species inside the MOF pores, and also of the various types of encapsulated systems that have been prepared so far. The chapter ends by illustrating the possible benefits of using MOF-based composites, which comprise: (1) increased stability of the encapsulated species; (2) shape-selectivity; and (3) multifunctionality.