Electrochemical conversion of CO 2 to alcohols is one of the most challenging methods of conversion and storage of electrical energy in the form of high-energy fuels. The challenge lies in the catalyst design to enable its real-life implementation. Herein, we demonstrate the synthesis and characterization of a cobalt(III) triphenylphosphine corrole complex, which contains three polyethylene glycol residues attached at the meso -phenyl groups. Electron-donation and therefore reduction of the cobalt from cobalt(III) to cobalt(I) is accompanied by removal of the axial ligand, thus resulting in a square-planar cobalt(I) complex. The cobalt(I) as an electron-rich supernucleophilic d 8 -configurated metal centre, where two electrons occupy and fill up the antibonding d z 2 orbital. This orbital possesses high affinity towards electrophiles, allowing for such electronically configurated metals reactions with carbon dioxide. Herein, we report the potential dependent heterogeneous electroreduction of CO 2 to ethanol or methanol of an immobilized cobalt A 3 -corrole catalyst system. In moderately acidic aqueous medium (pH = 6.0), the cobalt corrole modified carbon paper electrode exhibits a Faradaic Efficiency (FE%) of 48 % towards ethanol production.

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1wileyonlinelibrary.com IntroductionHydrogen-bonded organic pigments are a class of materials familiar from applications in the colorant industry, where they fi nd widespread use as materials for robust outdoor paints, cosmetics, and printing inks. [ 1,2 ] Indigo, a natural product, is the oldest and still most widely produced organic dye and pigment ( Figure 1 ). [ 3 ] The intermolecular -NH … O = hydrogen bonding that characterizes indigo is exploited in most of the synthetic hydrogen-bonded pigments as well. This class of materials has proven to be nontoxic and safe for humans, and is considered safer than even several classes of food dyes. [ 4 ] Hydrogen-bonding as a supramolecular engineering tool is useful to control self-assembly and highly relevant to aqueous and biochemical systems. [ 5,6 ] Recently, we have found that indigo, [ 7 ] and some of its derivatives [ 8,9 ] demonstrate ambipolar transport in organic fi eldeffect transistors (OFETs), with mobility ranging from 0.01-0.4 cm 2 V -1 s -1 . We Epindolidiones-Versatile and Stable Hydrogen-Bonded Pigments for Organic Field-Effect Transistors and Light-Emitting DiodesEric Daniel Głowacki , * Giuseppe Romanazzi , Cigdem Yumusak , Halime Coskun , Uwe Monkowius , Gundula Voss , Max Burian , Rainer T. Lechner , Nicola Demitri , Günther J. Redhammer , Nevsal Sünger , Gian Paolo Suranna and Serdar Sariciftci Hydrogen-bonded pigments are remarkably stable high-crystal lattice energy organic solids. Here a lesser-known family of compounds, the epindolidiones, which demonstrates electronic transport with extraordinary stability, even in highly demanding aqueous environments, is reported. Hole mobilities in the range 0.05-1 cm 2 V -1 s -1 can be achieved, with lower electron mobilities of up to 0.1 cm 2 V -1 s -1 . To help understand charge transport in epindolidiones, X-ray diffraction is used to solve the crystal structure of 2,8-difl uoroepindolidione and 2,8-dichloroepindolidione. Both derivatives crystallize with a linear-chain H-bonding lattice featuring two-dimensional π-π stacking. Powder diffraction indicates that the unsubstituted epindolidione has very similar crystallinity. All types of epindolidiones measured here display strong low-energy optical emission originating from excimeric states, which coexists with higher-energy fl uorescence. This can be exploited in light-emitting diodes, which show the same hybrid singlet and low-energy excimer electroluminescence. Low-voltage FETs are fabricated with epindolidione, which operate reliably under repeated cyclic tests in different ionic solutions within the pH range 3-10 without degradation. Finally, in order to overcome the insolubility of epindolidiones in organic solvents, a chemical procedure is devised to allow solution-processing via the introduction of suitable thermolabile solubilizing groups. This work shows the versatile potential of epindolidione pigments for electronics applications.

Conductive polydopamines represent bioinspired paradigm catalysts for efficiently recycling greenhouse gas CO2 to synthetic fuel.

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