One, Two Three - Phosphaalkene Decoration Tailoring Solubility and Electronic Properties of Truxene-Based Electron Acceptors.

We report the functionalization and deplanarization of truxenes using pnictaalkene fragments. Selective introduction of one, two, or three Mes*-Pn fragments provides up to three fully reversible reductions based on the Pn=C fragments. The incorporation of the unsaturated heteroelement fragment as well as the contortion of the truxene core result in significantly red-shifted absorption spectra and interesting opto-electronic properties which are studied by electrochemistry and spectro-electrochemistry. Incorporation of arsaalkene (As=C) motifs gives significantly milder reduction potentials and red-shifted absorption, while phosphaalkene decorated truxene P3 can be functionalized using Au(I)Cl coordination. Furthermore, solubility is markedly increased upon incorporation of the Pn-Mes* fragments which renders these materials suitable for solution processing.

Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes.

The development of new materials for solar-to-energy conversion should consider stability, ease of fabrication, and beneficial photophysical properties. In this context, a set of novel π-conjugated building blocks, with phospha- and arsaalkenes possessing a unique dithienyl annulated heterofulvenoid core, have been prepared as air- and moisture-stable sensitizers. These compounds unify electron-donor and -acceptor moieties, making them potential candidates for light-harvesting applications. Optical characterization of these systems was performed by steady-state and time-resolved absorption spectroscopy, supported by time-dependent DFT calculations. Tuning of the optical properties of these systems can be achieved by varying the pnictogen element at the bridgehead position, giving a bathochromic shift of ≈40 nm and coordinating the phosphaalkene towards gold AuI centers. The latter results in a ≈2000-fold extension of the ≈10 ps lifetime of uncoordinated systems well into the ns regime.

Organophosphorus Compounds in Organic Electronics.

This Minireview describes recent advances of organophosphorus compounds as opto-electronic materials in the field of organic electronics. The progress of (hetero-) phospholes, unsaturated phosphanes, and trivalent and pentavalent phosphanes since 2010 is covered. The described applications of organophosphorus materials range from single molecule sensors, field effect transistors, organic light emitting diodes, to polymeric materials for organic photovoltaic applications.

In situ assembly of bioresorbable organic bioelectronics in the brain.

Bioelectronics can potentially complement classical therapies in nonchronic treatments, such as immunotherapy and cancer. In addition to functionality, minimally invasive implantation methods and bioresorbable materials are central to nonchronic treatments. The latter avoids the need for surgical removal after disease relief. Self-organizing substrate-free organic electrodes meet these criteria and integrate seamlessly into dynamic biological systems in ways difficult for classical rigid solid-state electronics. Here we place bioresorbable electrodes with a brain-matched shear modulus-made from water-dispersed nanoparticles in the brain-in the targeted area using a capillary thinner than a human hair. Thereafter, we show that an optional auxiliary module grows dendrites from the installed conductive structure to seamlessly embed neurons and modify the electrode's volume properties. We demonstrate that these soft electrodes set off a controlled cellular response in the brain when relaying external stimuli and that the biocompatible materials show no tissue damage after bioresorption. These findings encourage further investigation of temporary organic bioelectronics for nonchronic treatments assembled in vivo.