Metal-Free Organic Optoelectronic Molecule as a Highly Efficient Photocatalyst for the Degradation of Organic Pollutants

Carbon Dot as Visible-Light Photoredox Catalysts for a Myriad of Organic Transformations

Metal-free catalysts for various organic transformations are of high demand now. In this study, we present a new carbon dot as an efficient metal-free nanophotocatalyst for carrying out a series of organic bond formation reactions. Using a single photocatalyst carbon dot, Csp2-Csp2, Csp2-B, Csp2-S, Csp2-Se, and C-P bond formation reactions were performed with a high yield of the corresponding products. Moreover, Csp2-H activation of the aromatic ring was achieved by merging the carbon dot photocatalyst with a transition metal. Interestingly, these carbon nanodot-based catalysts show good recyclability a few times without any significant loss of catalytic activity. The development of catalytic systems based on carbon dots has its merits vested in the advantageous properties of this nanomaterial, such as a robust chemical nature and cheap cost of preparation. This report demonstrates that a carbon dot indeed holds the potential to replace expensive metal-based catalysts as well as organic dyes in five different photoredox reactions.

Iron Porphyrin as a Cytochrome P450 Model for the Degradation of Dye

Organic dyes are widely used in the textile, biological, medical and other fields. However, a serious environmental problem has appeared because of the presence of organic dyes in industrial aqueous effluents. Thus, the efficient treatment of organic dyes in industrial wastewaters is currently in real demand. The current study investigated the oxidative degradation of the organic dye gentian violet by meso-tetra(carboxyphenyl) porphyriniron(III), [Fe^III(TCPP)] as a cytochrome P450 model and iodosylbenzene (PhIO) as an oxidant at room temperature. The degradation reaction was monitored by UV-vis absorption spectroscopy via the observation of UV-vis spectral changes of the gentian violet. The results showed that the efficiency of catalyzed degradation reached more than 90% in 1 h, indicating the remarkable oxidative degradation capacity of the [Fe^III(TCPP)]/PhIO system, which provided an efficient approach for the treatment of dyeing wastewater.

New Approach in the Application of Conjugated Polymers: The Light-Activated Source of Versatile Singlet Oxygen Molecule

For many years, the research on conjugated polymers (CPs) has been mainly focused on their application in organic electronics. Recent works, however, show that due to the unique optical and photophysical properties of CPs, such as high absorption in UV–Vis or even near-infrared (NIR) region and efficient intra-/intermolecular energy transfer, which can be relatively easily optimized, CPs can be considered as an effective light-activated source of versatile and highly reactive singlet oxygen for medical or catalytic use. The aim of this short review is to present the novel possibilities that lie dormant in those exceptional polymers with the extended system of π-conjugated bonds.

π-Extended Polyaromatic Hydrocarbons by Sustainable Alkyne Annulations through Double C-H/N-H Activation

The widespread applications of substituted diketopyrrolopyrroles (DPPs) call for the development of efficient methods for their modular assembly. Herein, we present a π-expansion strategy for polyaromatic hydrocarbons (PAHs) by C-H activation in a sustainable fashion. Thus, twofold C-H/N-H activations were accomplished by versatile ruthenium(II)carboxylate catalysis, providing step-economical access to diversely decorated fluorogenic DPPs that was merged with late-stage palladium-catalyzed C-H arylation on the thus-assembled DPP motif.