Luminescence Enhancement of cis-[Ru(bpy)(py)] via Confinement within a Metal-Organic Framework.

We report the synthesis, characterization, and photophysical and photochemical properties of [Ru(bpy)(py)]@Zn-oxalate metal-organic framework (Ru@MOF; bpy is 2,2'-bipyridine and py is pyridine). In Ru@MOF, the cavities of the anionic Zn-oxalate MOF tightly encapsulate [Ru(bpy)(py)] complexes, thereby altering the vibrational and electronic states of [Ru(bpy)(py)] and preventing photosubstitution of py ligands. [Ru(bpy)(py)] in Ru@MOF exhibits significantly increased photoluminescence lifetime and quantum yield, likely through destabilizing the dd state and enhancing photochemical stability.

Efficient Electrocatalytic Proton Reduction with Carbon Nanotube-Supported Metal-Organic Frameworks.

Hydrogen production from Earth-abundant catalysts remains an important but difficult challenge. Here we report the growth of Hf-porphyrin metal-organic frameworks (MOFs) on carbon nanotubes (CNTs) for electrocatalytic proton reduction. Covalent attachment of MOF nanoplates to conductive CNTs improves electron transfer from the electrode to Co-porphyrin active sites, which leads to effective proton reduction via protonation of a Co-H intermediate.

Merging Photoredox and Organometallic Catalysts in a Metal-Organic Framework Significantly Boosts Photocatalytic Activities.

Metal-organic frameworks (MOFs) have been extensively used for single-site catalysis and light harvesting, but their application in multicomponent photocatalysis is unexplored. We report here the successful incorporation of an Ir photoredox catalyst and a Ni cross-coupling catalyst into a stable Zr MOF, Zr -Ir-Ni, to efficiently catalyze C-S bond formation between various aryl iodides and thiols. The proximity of the Ir and Ni catalytic components to each other (ca.

Electron Injection from Photoexcited Metal-Organic Framework Ligands to Ru Secondary Building Units for Visible-Light-Driven Hydrogen Evolution.

We report the design of two new metal-organic frameworks (MOFs), Ru-TBP and Ru-TBP-Zn, based on Ru secondary building units (SBUs) and porphyrin-derived tetracarboxylate ligands. The proximity of Ru SBUs to porphyrin ligands (∼1.1 nm) facilitates multielectron transfer from excited porphyrins to Ru SBUs to enable efficient visible-light-driven hydrogen evolution reaction (HER) in neutral water.

Nanoscale Metal-Organic Frameworks for Ratiometric Oxygen Sensing in Live Cells.

We report the design of a phosphorescence/fluorescence dual-emissive nanoscale metal-organic framework (NMOF), R-UiO, as an intracellular oxygen (O2) sensor. R-UiO contains a Pt(II)-porphyrin ligand as an O2-sensitive probe and a Rhodamine-B isothiocyanate ligand as an O2-insensitive reference probe. It exhibits good crystallinity, high stability, and excellent ratiometric luminescence response to O2 partial pressure.

Graphene-Immobilized fac-Re(bipy)(CO)3Cl for Syngas Generation from Carbon Dioxide.

We report the synthesis of fac-M(4-amino-bipy)(CO)3X (M = Mn and X = Br or M = Re and X = Cl, with bipy = 2,2'-bipyridine), their immobilization on graphene oxide (GrO) via diazonium grafting, and the use of Re-functionalized GrO for electrocatalytic syngas production. Infrared (IR) spectroscopy, X-ray absorption fine structure (XAFS) spectroscopy, and electrocatalysis indicated successful grafting of the Re catalyst onto GrO. Re-functionalized GrO was then deposited onto a glassy carbon electrode (GCE) for CO2 reduction.