stilbenes and pyridine

Developing photocatalytic H2 production devices is the one of the key steps for constructing a global H2-based renewable energy infrastructure. A number of photoactive assemblies have emerged where a photosensitizer and cobaloxime-based H2 production catalysts work in tandem to convert light energy into the H-H chemical bonds. However, the long-term instability of these assemblies and the need for hazardous proton sources have limited their usage. Here, in this work, we have integrated a stilbene-based organic dye into the periphery of a cobaloxime core via a distinct axial pyridine linkage. This strategy allowed us to develop a photosensitizer-catalyst hybrid structure with the same molecular framework. In this article, we have explained the detailed procedure of the synthesis of this hybrid molecule in addition to its comprehensive chemical characterization. The structural and optical studies have exhibited an intense electronic interaction between the cobaloxime core and the organic photosensitizer. The cobaloxime was active for H2 production even in the presence of water as the proton source. Here, we have developed a simple airtight system connected with an online H2 detector for the investigation of the photocatalytic activity by this hybrid complex. This photosensitizer-catalyst dyad present in the experimental setup continuously produced H2 once it was exposed in the natural sunlight. This photocatalytic H2 production by the hybrid complex was observed in aqueous/organic mixture media in the presence of a sacrificial electron donor under complete aerobic conditions. Thus, this photocatalysis measurement system along with the photosensitizer-catalyst dyad provide valuable insight for the development of next generation photocatalytic H2 production devices.

Topics: Catalysis; Conservation of Energy Resources; Hydrogen; Organometallic Compounds; Photosensitizing Agents; Protons; Pyridines; Stilbenes; Sunlight; Water

We presented a novel approach for pyrophosphate (PPi) sensing. Two tetraphenylethene (TPE)-functionalised pyridine salts (TPM and TPH) were designed and synthesized. Both of them exhibited weak emission in the solution state that originates from intramolecular charge transfer (ICT) from TPE to the pyridine; the addition of PPi into the TPM aqueous solution would enhance the fluorescence intensity, which eliminates the emission quenching effect of the iodide ion by the formation of PPi-sensor nanoparticles. The detection limit of TPM was determined to be as low as 133 nM. Meanwhile, a thin solid film of TPM that could detect PPi rapidly was conveniently prepared.

Topics: Chemistry Techniques, Analytical; Diphosphates; Fluorescent Dyes; HeLa Cells; Humans; Limit of Detection; Pyridines; Salts; Spectrometry, Fluorescence; Stilbenes