Metallo-organic Conjugated Systems for Organic Electronics

Photophysical and Primary Self-Referencing Thermometric Properties of Europium Hydrogen-Bonded Triazine Frameworks

Lanthanide hydrogen-bonded organic frameworks (LnHOFs) are recently emerging as a novel versatile class of multicomponent luminescent materials with promising potential applications in optics and photonics. Trivalent europium (Eu³⁺) incorporated polymeric hydrogen-bonded triazine frameworks (PHTF:Eu) have been successfully obtained via a facile and low-cost thermal pyrolysis route. The PHTF:Eu material shows a porous frame structure principally composed of isocyanuric acid and ammelide as a minor constituent. Intense red luminescence with high colour-purity from Eu³⁺ is obtained by exciting over a broad absorption band peaked at 300 nm either at room or low temperature. The triazine-based host works as excellent optical antenna towards Eu³⁺, yielding ~42% sensitization efficiency (η_sens) and an intrinsic quantum yield of Eu³⁺ emission (Φ_Eu) as high as ~46%. Temperature-dependent emission studies show that PHTF:Eu displays relatively high optical stability at elevated temperatures in comparison to traditional inorganic phosphors. The retrieved activation energy of 89 meV indicates that thermal quenching mechanisms are attributed to the intrinsic energy level structure of the metal-triazine assembly, possibly via a thermally activated back transfer to ligand triplet or CT states. Finally, by using an innovative approach based on excitation spectra, we demonstrate that PHTF:Eu can work as a universal primary self-referencing thermometer based on a single-emitting center with excellent relative sensitivity in the cryogenic temperature range.

Copper Coordination Complexes for Energy-Relevant Applications

Copper coordination complexes have emerged as a group of transition metal complexes that play important roles in solar energy conversion, utilization and storage, and have the potential to replace the quintessential commonly used transition metals, like Co, Pt, Ir and Ru as light sensitizers, redox mediators, electron donors and catalytic centers. The applications of copper coordination compounds in chemistry and energy related technologies are many and demonstrate their rightful place as sustainable, low toxicity and Earth-abundant alternative materials. In this perspective we show the most recent impact made by copper coordination complexes in dye-sensitized solar cells and other energy relevant applications.

Effects of chalcogen atom variation in chalcogenadiazole fused indolo[2,3-a]carbazoles

The chalcogen (O/S/Se)-induced intriguing variation of structural and optoelectronic properties in a series of chalcogenadiazole-fused indolo[2,3-a]carbazole donor–acceptor (D–A) molecules.

Effect of heteroatom (S/Se) juggling in donor–acceptor–donor (D–A–D) fused systems: synthesis and electrochemical polymerization

Planarization of donor–acceptor–donor (D–A–D) systems through N-bridges with systematic alteration of S/Se atom(s) resulted in interesting fluorosolvatochromic molecules and their electrochemical polymers.

Thienopyrrole and selenophenopyrrole donor fused with benzotriazole acceptor: microwave assisted synthesis and electrochemical polymerization

Thieno-/selenophenopyrrole fused substituted benzotriazoles were synthesized by microwave assisted cyclization with reduced reaction times. Electrochemically obtained polymers of the benzotriazoles showed the formation of a polaron and bipolaron with a 0.1 V bias difference.