The mesoporous silica SBA-15, functionalised with propylthiol groups during synthesis and rendered porous (mean pore diameter 51 Å) by extraction of surfactant template molecules, shows strong and size selective adsorption of proteins, selectively excluding those with molecular weights of ca. 40000 u and above. A model for the adsorption process is proposed, in which reversible physisorption is followed by irreversible chemisorption. Adsorption of proteins on an unfunctionalised SBA-15 from which the template has been removed by calcination, (mean pore diameter 56 Å) shows shape selective and reversible adsorption of proteins with molecular weights of ca. 43000 u and below.

The porous metal organic frameworks scandium trimesate MIL-100(Sc), scandium terephthalates MIL-101(Sc), MIL-88B(Sc) and MIL-68(Sc), scandium 4,4′-biphenyl-dicarboxylate MIL-88D(Sc) and the scandium 3,3′,5,5-azobenzene-tetracarboxylate socMOF(Sc) have been compared as Lewis acid catalysts against Sc³⁺-exchanged zeolite Beta, MIL-100(Cr), MIL-101(Cr), MIL-100(Fe) and the divalent MOFs HKUST-1(Cu), CPO-27(Ni) and STA-12(Ni), each of which can be prepared with coordinatively unsaturated metal sites. The performance of these MOFs has been investigated in several Lewis acid-catalysed reactions that are of importance in organic synthesis but have rarely been studied using MOF catalysts. These reactions were (i) the intermolecular carbonyl ene reaction of nucleophilic alkenes and electron-poor aldehydes, (ii) a Friedel–Crafts type Michael addition between electron-rich heterocycles and electron-deficient alkenes and (iii) ketimine and aldimine formation. In each of these, MIL-100(Sc) is both active and selective and significantly outperforms the other catalysts. Filtration and recycle tests indicate that catalysis over MIL-100(Sc) is heterogeneous. The study of Michael addition reactions carried out over scandium-bearing MOFs with different window sizes on indole-based substrates of varying molecular dimensions indicates that most of the catalysis that involves molecules small enough to enter the pores occurs within the internal pore space. These results indicate MIL-100(Sc) is an exceptional Lewis acidic MOF catalyst, and suggest that MIL-100(Sc) and new derivatives of it could find application as recyclable solid catalysts in synthetic chemistry.

The first large pore (free diameter > 7 Å) metal phosphonates have been prepared as divalent metal N,N′-piperazinebis(methylenephosphonate)s that possess pores greater than ca. 10 Å in free diameter, are stable up to 400 °C and offer a route to chiral adsorbents and catalysts.

In September 2018, the First European Workshop on Metal Phosphonates Chemistry brought together some prominent researchers in the field of metal phosphonates and phosphinates with the aim of discussing past and current research efforts and identifying future directions. The scope of this perspective article is to provide a critical overview of the topics discussed during the workshop, which are divided into two main areas: synthesis and characterisation, and applications. In terms of synthetic methods, there has been a push towards cleaner and more efficient approaches. This has led to the introduction of high-throughput synthesis and mechanochemical synthesis. The recent success of metal–organic frameworks has also promoted renewed interest in the synthesis of porous metal phosphonates and phosphinates. Regarding characterisation, the main advances are the development of electron diffraction as a tool for crystal structure determination and the deployment of in situ characterisation techniques, which have allowed for a better understanding of reaction pathways. In terms of applications, metal phosphonates have been found to be suitable materials for several purposes: they have been employed as heterogeneous catalysts for the synthesis of fine chemicals, as solid sorbents for gas separation, notably CO₂ capture, as materials for electrochemical devices, such as fuel cells and rechargeable batteries, and as matrices for drug delivery.