A cobalt-based catalyst for the hydrogenation of CO2 under ambient conditions.

Because of the continually rising levels of CO2 in the atmosphere, research for the conversion of CO2 into fuels using carbon-neutral energy is an important and current topic in catalysis. Recent research on molecular catalysts has led to improved rates for conversion of CO2 to formate, but the catalysts are based on precious metals such as iridium, ruthenium and rhodium and require high temperatures and high pressures. Using established thermodynamic properties of hydricity (ΔGH(-)) and acidity (pKa), we designed a cobalt-based catalyst system for the production of formate from CO2 and H2.

An organometallic building block approach to produce a multidecker 4f single-molecule magnet.

An organometallic building block strategy was employed to investigate the magnetic properties of a Ln(III) organometallic single-ion magnet (SIM) and subsequent single-molecule magnet (SMM) after coupling two of the monomeric units. New homoleptic Dy(III)COT″2 and Ln(III)2COT″3 (Ln = Gd, Dy) complexes have been synthesized. DFT calculations of the bimetallic Dy(III) complex indicate strong metal-ligand covalency and uneven donation to the Dy(III) ions by the terminal and internal COT″(2-) (cyclooctatetraenide) rings that correlate with the respective bond distances.

First structural evidence for multiple alkali metals between sandwich decks in a metallocene.

A tetralithio salt (1) derived by treating 1,4-bis(trimethylsilyl)-cyclooctatriene with (n)BuLi serves as the first structural evidence for a multi-alkali metallocene. Single-crystal XRD confirms two Li(+) each asymmetrically bind to η(3) and η(4) between two COT'' rings and two Li(+) terminally bind to η(3). Solid-state NMR studies confirm the presence of two distinct lithium ion sites while the solution NMR studies suggest the formation of an (COT'' dianion) ion-pair in solution.

An organometallic sandwich lanthanide single-ion magnet with an unusual multiple relaxation mechanism.

A dysprosium(III) sandwich complex, [Dy(III)(COT″)(2)Li(THF)(DME)], was synthesized using 1,4-bis(trimethylsilyl)cyclooctatetraenyl dianion (COT″). The complex behaves as a single-ion magnet and demonstrates unusual multiple relaxation modes. The observed relaxation pathways strongly depend on the applied static dc fields.

A new chiral di-N-heterocyclic carbene (NHC) cyclophane ligand and its application in palladium enantioselective catalysis.

This report details the synthesis and characterization of the first chiral diNHC cyclophane ligand and its palladium allyl complex. The complex was tested for 1,4-conjugate addition of phenylboronic acid to 2-cyclohexen-1-one and provides R-3-phenylcyclohexanone in 50% enantiomeric excess.

New iridium and rhodium chiral di-N-heterocyclic carbene (NHC) complexes and their application in enantioselective catalysis.

New iridium and rhodium complexes prepared from C2-symmetric trans-9,10-dihydro-9,10-ethanoanthracene-11,12-bis(1-R)-benzimidazolidine-2-ylidene ligands (R=Me, iPr, and diPh) have been synthesized and characterized. Their catalytic activities have been tested in enantioselective hydrogenation and hydroformylation reactions. The ee's for the reactions are low.