Donor Ability of Bisphosphinemonoxide Ligands Relevant to Late-Metal Olefin Polymerization Catalysis.

Late-transition-metal catalysts for polymerization of olefins have drawn a significant amount of attention owing to their ability to tolerate and incorporate polar comonomers. However, a systematic way to experimentally quantify the electronic properties of the ligands used in these systems has not been developed. Quantified ligand parameters will allow for the rational design of tailored polymerization catalysts, which would target specific polymer properties.

Systematic evaluation of the electronic effect of aluminum-containing ligands in iridium-aluminum and rhodium-aluminum bimetallic complexes.

Pyridinemethanolate and oxyquinoline derivatives of previously reported late transition metal-aluminum heterobimetallic complexes containing iridium and rhodium have been synthesized and characterized. A combination of experimental and computational data permits a direct comparison of the electronic effects of each novel aluminum-containing ligand in our library on the late transition metal centers. Alongside electronic data of previously reported oxypyridine bridged systems, we conclude that the addition of a dialkylaluminum(X) (X = anion) fragment does not significantly perturb the electron donor ability of the bridging ligand.

Copper-based redox shuttles supported by preorganized tetradentate ligands for dye-sensitized solar cells.

Three copper redox shuttles ([Cu(1)]2+/1+, [Cu(2)]2+/1+, and [Cu(3)]2+/1+) featuring tetradentate ligands were synthesized and evaluated computationally, electrochemically, and in dye-sensitized solar cell (DSC) devices using a benchmark organic dye, Y123. Neutral polyaromatic ligands with limited flexibility were targeted as a strategy to improve solar-to-electrical energy conversion by reducing voltage losses associated with redox shuttle electron transfer events. Inner-sphere electron transfer reorganization energies (λ) were computed quantum chemically and compared to the commonly used [Co(bpy)3]3+/2+ redox shuttle which has a reported λ value of 0.