A Metal–Organic Framework with Cooperative Phosphines That Permit Post‐Synthetic Installation of Open Metal Sites

Abstract

PCM-101 is a phosphine coordination material comprised of tris(p-carboxylato)triphenylphosphine and secondary pillaring groups coordinated to [M (OH)] nodes (M=Co, Ni). PCM-101 has a unique topology in which R P: sites are arranged directly trans to one another, with a P⋅⋅⋅P separation distance dictated by the pillars. Post-synthetic coordination of soft metals to the P: sites proceeds at room temperature to provide X-ray quality crystals that permit full structural resolution. Addition of AuCl groups forces a large distortion of the parent framework. In contrast, CuBr undergoes insertion directly between the trans-P sites to form dimers that mimic solution-phase complexes, but that are geometrically strained due to steric pressure exerted by the MOF scaffold. The metalated materials are active in heterogeneous hydroaddition catalysis under mild conditions, yielding different major products compared to their molecular counterparts.

Metal‐Organic Frameworks and Metal‐Organic Cages – A Perspective

“…However, the nature of the building-block approach means that no metal is impossible to use in MOF formation and amongst naturally occurring metals it is difficult to find a metal that has not been investigated. Amongst linkers, certain classes of ligands are more commonly studied, e. g. di-and tri-carboxylates, [3b,14] bipyridyls [15] and imidazolates, [16] but this does not preclude other ligand types which are more commonly encountered in solution phase coordination chemistry, e. g. phosphorus [17] or sulfur-based [18] ligands. Other ligands such as N-heterocyclic carbenes are rarely used for MOF propagation, i. e. binding to the metal nodes of the framework, but can be incorporated into MOFs, either decorating or appended to the overall framework.…”

Isolating reactive metal-based species in Metal–Organic Frameworks – viable strategies and opportunities

“…Seminal works by Humphrey et al described the preparation of mixed-linker MOFs featuring free phosphine 137 or arsine 138 donor sites which are accessible via porous channels. The monodentate P-or As-donors undergo PSM with retention of framework crystallinity, allowing the new metal centres to be studied via X-ray crystallography.…”

A Metal–Organic Framework with Cooperative Phosphines That Permit Post‐Synthetic Installation of Open Metal Sites

“…C) Alternative view in the ab plane sowing the larger diamond-shaped pores with trans-oriented P: sites [22]. B) Space-filling model of PCM-101 in the crystallographic bc plane showing square channels decorated with P: sites.…”

“…This conversion is well understood in homogeneous systems, and is catalyzed by late transition-metal complexes, [17] including Cu I and Au I . Intramolecular nucleophilic attack by [22] the alcohol followed by proton transfer yields the gem-alkene, 2,which quickly reacts with water to give the hemi-acetal, 3. Intramolecular nucleophilic attack by [22] the alcohol followed by proton transfer yields the gem-alkene, 2,which quickly reacts with water to give the hemi-acetal, 3.…”