PCM-22, a metal-organic framework material comprising triphenylphosphine and Ln 3+ ions (Ln = Pr-Yb), exhibits solid-state luminescence at room temperature. Mixed-metal versions of PCM-22 that contain controlled amounts of Eu 3+ , Gd 3+ , and Tb 3+ function as highly sensitive, broad-scope solid-state sensors that can rapidly identify unknown solvents by providing a unique ''eight-factor'' fingerprint. The sensors allow for immediate solvent identification via color changes that are obvious to the naked eye and also permit quantitative chemical analysis by uncomplicated spectrophotometry. These same materials achieve quantitative detection of H 2 O in D 2 O from 10 to 120,000 ppm. The detection of trace H 2 O is also demonstrated in a range of common solvents, including those incompatible with conventional laboratory titration methods.

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.

We present the synthesis of Ag−Ir alloys in the form of solid-solution nanoparticles (NPs). Ag and Ir are classically immiscible in the bulk and therefore the physical properties of Ag−Ir alloys are unknown. A convenient microwaveassisted, solution-phase method that employs readily available Ag(NO 3 ) and IrCl 3 precursors enables the preparation of small (2.5−5.5 nm) Ag−IrNPs with alloyed structures. Ag x Ir (100−x) NPs can be obtained by this method between x = 6−31. The Ag−IrNPs resist dealloying upon heating up to 300 °C. Ir-rich Ag−IrNPs dispersed on amorphous silica are significantly more active gas-phase alkene hydrogenation catalysts than pure IrNPs. Density functional theory (DFT) and theoretical modeling studies reveal that the Ag−IrNPswhich are consistently larger than monometallic IrNPs prepared under the same conditionshave comparatively fewer strong H-binding edge sites. This promotes faster H atom transfer to coadsorbed alkenes. Ag−IrNPs supported on amorphous Co 3 O 4 show a linear composition dependence in the selective hydrogenation of CO versus CC bonds: more Ag-rich Ag−IrNPs are more selective toward CO hydrogenation of the α,β-unsaturated aldehyde crotonaldehyde, yielding the industrially desirable crotyl alcohol. Furthermore, deposition of Ag−IrNPs inside Co 3 O 4 mesopores results in an additional ∼56% selectivity enhancement.

National Laboratory under Contract DE-AC02-06CH11357. ■ ABBREVIATIONSGPa, gigapascals; d c , distance between ring centroids; d p , distance between parallel ring planes; ϕ, slippage angle between rings; fs, femtoseconds; P, T, pressure and temperature; syn-NN, structure in which each NN bond is oriented along the same side of the nanothread; anti-NN, structure in which NN bonds are oriented along alternating sides of the nanothread; PXRD, powder X-ray diffraction; FTIR, Fouriertransform infrared spectroscopy; DAC, diamond anvil cell; NMR, nuclear magnetic resonance.

A tetra(carboxylated) PCP pincer ligand has been synthesized as a building block for porous coordination polymers (PCPs). The air- and moisture-stable PCP metalloligands are rigid tetratopic linkers that are geometrically akin to ligands used in the synthesis of robust metal-organic frameworks (MOFs). Here, the design principle is demonstrated by cyclometalation with Pd(II) Cl and subsequent use of the metalloligand to prepare a crystalline 3D MOF by direct reaction with Co(II) ions and structural resolution by single crystal X-ray diffraction. The Pd-Cl groups inside the pores are accessible to post-synthetic modifications that facilitate chemical reactions previously unobserved in MOFs: a Pd-CH3 activated material undergoes rapid insertion of CO2 gas to give Pd-OC(O)CH3 at 1 atm and 298 K. However, since the material is highly selective for the adsorption of CO2 over CO, a Pd-N3 modified version resists CO insertion under the same conditions.