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.

Pyrrole based organic cages for selective CO2 capture.

PCM-102 is a new organophosphine metal–organic framework (MOF) featuring diphosphine pockets that consist of pairs of offset trans-oriented P­(III) donors. Postsynthetic addition of M­(I) salts (M = Cu, Ag, Au) to PCM-102 induces single-crystal to single-crystal transformations and the formation of trans-[P2M]+ solid-state complexes (where P = framework-based triarylphosphines). While the unmetalated PCM-102 has low porosity, the addition of secondary Lewis acids to install rigid P–M–P pillars is shown to dramatically increase both stability and selective gas uptake properties, with N2 Brunauer–Emmett–Teller surface areas >1500 m2 g–1. The Ag­(I) analogue can also be obtained via a simple, one-pot peri-synthetic route and is an ideal sacrificial precursor for materials with mixed bimetallic MA/MB pillars via postsynthetic, solvent-assisted metal exchange. Notably, the M-PCM-102 family of MOFs contain periodic trans-[P2M]+ sites that are free of counter anions, unlike traditional analogous molecular complexes, since the precursor PCM-102 MOF is monoanionic, enabling access to charge-neutral metal-pillared materials. Four M-PCM-102 materials were evaluated for the separation of C2 hydrocarbons. The separation performance was found to be tunable based on the metal(s) incorporated, and density functional theory was employed to elucidate the nature of the unusual observed sorption preference, C2H2 > C2H6 > C2H4.

A series of α-acyl formamidinium ions and their corresponding 1-electron reduced neutral radicals were synthesized, and their electrochemical properties were evaluated. These cations exhibit multi-electron redox processes that are highly electrochemically reversible at rapid scan rates (100 mV s(-1)), and the redox potentials were readily tailored by up to ∼1.0 V, making them ideal candidates for organic radical-based charge storage materials.