Predictive energetic tuning of C-Nucleophiles for the electrochemical capture of carbon dioxide.

This work maps the thermodynamics of electrochemically generated C-nucleophiles for reactive capture of CO. We identify a linear relationship between the pK, the reduction potential of a protonated nucleophile ( ), and the nucleophile's free energy of CO binding ( ). Through synergistic experiments and computations, this study establishes a three-parameter correlation described by the equation for a series of twelve imidazol(in)ium/N-heterocyclic carbene pairs with an of 0.

Chemical and Electrochemical Recycling of End-Use Poly(ethylene terephthalate) (PET) Plastics in Batch, Microwave and Electrochemical Reactors.

This work describes new methods for the chemical recycling of end-use poly(ethylene terephthalate) (PET) in batch, microwave and electrochemical reactors. The reactions are based on basic hydrolysis of the ester moieties in the polymer framework and occur under mild reaction conditions with low-cost reagents. We report end-use PET depolymerization in refluxing methanol with added NaOH with 75% yield of terephthalic acid in batch after 12 h, while yields up to 65% can be observed after only 40 min under microwave irradiation at 85 °C.

Metalloradical intermediates in electrocatalytic reduction of CO to CO: Mn versus Re bis-N-heterocyclic carbene pincers.

This work examines the relative reactivities of Re and Mn tricarbonyl pyridine-2,6-bis-N-heterocyclic carbene pincers M(CO)CNCX (M = Re, Mn and X = Cl and Br) towards catalysis for the electrochemical conversion of CO to CO. Unlike prior well-studied group VII catalysts, Mn(CO)CNCX is extraordinarily active, while the new Re(CO)CNCX complex surprisingly does not exhibit catalytic response. DFT calculations shed light on this puzzling behavior and show that the redox-active pyridine-2,6-bis-N-heterocyclic carbene ligand facilitates the reduction of the ground-state complexes; however, the extent of electronic delocalization in the reduced intermediates differs in the degree of metalloradical character.