Synthesis of Polydiynes via an Unexpected Dimerization/Polymerization Sequence of C3 Propargylic Electrophiles.

Here, we describe the unexpected discovery of a Cu-catalyzed condensation polymerization reaction of propargylic electrophiles (CPPE) that transforms simple C3 building blocks into polydiynes of C6 repeating units. This reaction was achieved by a simple system composed of a copper acetylide initiator and an electron-rich phosphine ligand. Alkyne polymers (up to 33.8 kg/mol) were produced in good yields and exclusive regioselectivity with high functional group compatibility. Hydrogenation of the product afforded a new polyolefin-type backbone, while base-mediated isomerization led to a new type of dienyne-based electron-deficient conjugated polymer. Mechanistic studies revealed a new α-α selective Cu-catalyzed dimerization pathway of the C3 unit, followed by in situ organocopper-mediated chain-growth propagation. These insights not only provide an important understanding of the Cu-catalyzed CPPE of C3, C4, and C6 monomers in general but also lead to a significantly improved synthesis of polydiynes from simpler starting materials with handles for the incorporation of an α-end functional group.

Neurological impairment is crucial for tire rubber-derived contaminant 6PPDQ-induced acute toxicity to rainbow trout.

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPDQ) has attracted significant attention due to its highly acute lethality to sensitive salmonids. However, studies investigating the mechanisms underlying its acute toxicity have been lacking. In this work, we demonstrated the sensitivity of rainbow trout to 6PPDQ-induced mortality. Moribund trout exhibited significantly higher brain concentrations of 6PPDQ compared to surviving trout. In an in vitro model using human brain microvascular endothelial cells, 6PPDQ can penetrate the blood-brain barrier and enhance blood-brain barrier permeability without compromising cell viability. The time spent in the top of the tank increased with rising 6PPDQ concentrations, as indicated by locomotion behavior tests. Furthermore, 6PPDQ influenced neurotransmitter levels and mRNA expression of neurotransmission-related genes in the brain and exhibited strong binding affinity to target neurotransmission-related proteins using computational simulations. The integrated biomarker response value associated with neurotoxicity showed a positive linear correlation with trout mortality. These findings significantly contribute to filling the knowledge gap between neurological impairments and apical outcomes, including behavioral effects and mortality, induced by 6PPDQ.

Role of steel slags on biomass/carbon dioxide gasification integrated with recovery of high temperature heat.

Disposal of biomass in the agriculture and steel slags in the steel industry provides a significant solution toward sustainability in China. Herein these two sectors were creatively combined as a novel method, i.e., biomass/CO2 gasification using waste heat from hot slags where the influence of chemical compositions of steel slags, characterized as iron oxide content and basicity, on gasification thermodynamics, was systemically reported for the first time. Both the target gases of CO, H2 and CH4 and the polluted gases of NH3, NO and NO2 were considered. It was first found that an increasing iron content and slag basicity continuously improved the CO yield at 600-1000°C and 800-1000°C, respectively; while the effect on polluted gas releases was limited. Moreover, the solid wastes after gasification could be utilized to provide nutrients and improve the soil in the agriculture, starting from which an integrated modern system was proposed herein.