On the σ-dimerization of N,N-dimethyl-p-toluidine during anodic oxidation—A reinvestigation

Graphitic Carbon Nitride as Photocatalyst for the Direct Formylation of Anilines

The use of graphitic carbon nitride (g-CN) for the photocatalytic radical formylation of anilines, which represents a more sustainable and attractive alternative to the currently used approaches, is reported herein. Our operationally simple method occurs under mild conditions, employing air as an oxidant. In particular, the chemistry is driven by the ability of g-CN to reach an electronically excited state upon visible-light absorption, which has a suitable potential energy to trigger the formation of reactive α-amino radical species from anilines. Mechanistic investigations also proved the key role of the g-CN to form reactive superoxide radicals from O2 via single electron transfer. Importantly, this photocatalytic transformation provides a variety of functionalized formamides (15 examples, up to 89 % yield).

The influence of physicochemical properties on the processibility of conducting polymers: A bioelectronics perspective

Conducting polymers (CPs) possess unique electrical and electrochemical properties and hold great potential for different applications in the field of bioelectronics. However, the widespread implementation of CPs in this field has been critically hindered by their poor processibility. There are four key elements that determine the processibility of CPs, which are thermal tunability, chemical stability, solvent compatibility and mechanical robustness. Recent research efforts have focused on enhancing the processibility of these materials through pre- or post-synthesis chemical modifications, the fabrication of CP-based complexes and composites, and the adoption of additive manufacturing techniques. In this review, the physicochemical and structural properties that underlie the performance and processibility of CPs are examined. In addition, current research efforts to overcome technical limitations and broaden the potential applications of CPs in bioelectronics are discussed. STATEMENT OF SIGNIFICANCE: This review details the inherent properties of CPs that have hindered their use in additive manufacturing for the creation of 3D bioelectronics. A fundamental approach is presented with consideration of the chemical structure and how this contributes to their electrical, thermal and mechanical properties. The review then considers how manipulation of these properties has been addressed in the literature including areas where improvements can be made. Finally, the review details the use of CPs in additive manufacturing and the future scope for the use of CPs and their composites in the development of 3D bioelectronics.

In Situ Spectroelectrochemical-Conductance Measurements as an Efficient Tool for the Evaluation of Charge Trapping in Conducting Polymers

In situ UV-vis-NIR spectroelectrochemistry has been intensively used to evaluate the electronic transitions during the charging/discharging process of π-conjugated polymers. However, the type of charge carrier and the mechanisms of their transport, remains still a point of discussion. Herein, the coupling between UV-vis-NIR spectroscopy and in situ electrochemical-conductance measurements is proposed to compare the doping process of three different thiophene-based conducting polymers. The simultaneous monitoring of electrical and absorption properties, associated with low energy electronic transitions characteristic for polarons and bipolarons, was achieved. In addition, this method allows evaluating the reversible charge trapping mechanism of poly-3,4-o-xylendioxythiophene (PXDOT), caused by the formation of σ-dimers, making it a very useful tool to determine relevant physicochemical properties of conductive materials.