NO and NO Release from the Trityl Diazeniumdiolate Complexes [M(ONCPh)] (M = Fe, Co).

Reaction of MBr with 3 equiv of [K(18-crown-6)][ONCPh] generates the trityl diazeniumdiolate complexes [K(18-crown-6)][M(ONCPh)] (M = Co, ; Fe, ) in good yields. Irradiation of and using 371 nm light led to NO formation in 10 and 1% yields (calculated assuming a maximum of 6 equiv of NO produced per complex), respectively. NO was also formed during the photolysis of , in 63% yield, whereas photolysis of led to the formation of NO, as well as PhCN()OCPh, in 37 and 5% yields, respectively.

Interconvertible Living Radical and Cationic Polymerization using a Dual Photoelectrochemical Catalyst.

The necessity of well-tuned reactivity for successful controlled polymer synthesis often comes with the price of limited monomer substrate scope. We demonstrate here the on-demand interconversion between living radical and cationic polymerization using two orthogonal stimuli and a dual responsive single catalyst. The dual photo- and electrochemical reactivity of 10-phenylphenothiazine catalyst provides control of the polymer's molar mass and composition by orthogonally activating the common dormant species toward two distinct chemical routes.

Facile proton-coupled electron transfer enabled by coordination-induced E-H bond weakening to boron.

We report the facile activation of aryl E-H (ArEH; E = N, O, S; Ar = Ph or C6F5) or ammonia N-H bonds via coordination-induced bond weakening to a redox-active boron center in the complex, (1-). Substantial decreases in E-H bond dissociation free energies (BDFEs) are observed upon substrate coordination, enabling subsequent facile proton-coupled electron transfer (PCET). A drop of >50 kcal mol-1 in H2N-H BDFE upon coordination was experimentally determined.

Electrochemical Evaluation of Diketopyrrolopyrrole Derivatives for Nonaqueous Redox Flow Batteries.

Redox flow batteries (RFBs) employing nonaqueous electrolytes could potentially operate at much higher cell voltages, and therefore afford higher energy and power densities, than RFBs employing aqueous electrolytes. The development of such high-voltage nonaqueous RFBs requires anolytes that are electrochemically stable, especially in the presence of traces of oxygen and/or moisture. The inherent atmospheric reactivity of anolytes mandates judicious molecular design with high electron affinity and electrochemical stability.