Electrocatalytic CO reduction to formate by a cobalt phosphino-thiolate complex.

Electrochemical conversion of CO to value-added products serves as an attractive method to store renewable energy as energy-dense fuels. Selectivity in this type of conversion can be limited, often leading to the formation of side products such as H. The activity of a cobalt phosphino-thiolate complex ([Co(triphos)(bdt)]) towards the selective reduction of CO to formate is explored in this report.

Electronically-coupled redox centers in trimetallic cobalt complexes.

Synthesis and isolation of molecular building blocks of metal-organic frameworks (MOFs) can provide unique opportunities for characterization that would otherwise be inaccessible due to the heterogeneous nature of MOFs. Herein, we report a series of trinuclear cobalt complexes incorporating dithiolene ligands, triphenylene-2,3,6,7,10,11-hexathiolate (THT) (13+), and benzene hexathiolate (BHT) (23+), with 1,1,1,-tris(diphenylphosphinomethyl)ethane (triphos) employed as the capping ligand. Single crystal X-ray analyses of 13+ and 23+ display three five-coordinate cobalt centers bound to the triphos and dithiolene ligands in a distorted square pyramidal geometry.

Isotope Effects Reveal an Alternative Mechanism for "Iminium-Ion" Catalysis.

A novel mechanism for the epoxidation of enals with hydrogen peroxide catalyzed by diarylprolinol silyl ether supported by experimental C kinetic isotope effects (KIEs) and density functional theory calculations is presented. Normal C KIEs, measured on both the carbonyl- and β-carbon atoms of the enal, suggest participation of both carbon atoms in the rate-determining step. Calculations show that the widely accepted iminium-ion mechanism does not account for this experimental observation.