Selective Oxidation of Alkylarenes to the Aromatic Ketones or Benzaldehydes with Water.

Here a palladium-catalyzed oxidation method for converting alkylarenes into the aromatic ketones or benzaldehydes with water as the only oxygen donor is reported. This C-H bond oxidation functionalization does not require other oxidants and hydrogen acceptors, and H2 is the only byproduct. The oxygen atom introduced into the products is confirmed to be from water by the MS analysis on the product of the 18O-labeled water reaction.

pH-Mediated Synthesis and Mechanistic Study of Homogeneous Magnetic Ag@Fe3O4 Nanoparticles.

In this paper, we report a novel kind of pH-mediated homogeneous magnetic Ag@Fe3O4 nanoparticles prepared by facile one-pot synthesis. The nanostructure and surface element composition along with magnetism of the as-synthesized hybrid nanoparticles can be easily adjusted by pH value in synthetic process. Furthermore, XRD and XPS detections indicated that the two components in the nanoparticles are both independent and certain synergistic. Compared with magnetic silver nanoparticles prepared by traditional multi-step methods, the homogeneous Ag@Fe3O4 nanoparticles showed excellent monodispersity and stability. Moreover, corresponding formation mechanism of the homogeneous hybrid magnetic nanoparticles was demonstrated in detail. Catalytic application of the homogeneous hybrid nanoparticles prepared under different pH values also verified rationality of the formation mechanism from side. This research provides a general strategy for constructing and large-scale preparing homogeneous magnetic hybrid metal nanoparticles.

Naphtho[2,3-b]furan-4,9-dione synthesis via palladium-catalyzed reverse hydrogenolysis.

A reverse hydrogenolysis process has been developed for two-site coupling of 2-hydroxy-1,4-naphthoquinones with olefins to produce naphtha[2,3-b]furan-4,9-diones and hydrogen (H2). The reaction is catalyzed by commercially available Pd/C without oxidants and hydrogen acceptors, thereby providing an intrinsically waste-free approach for the synthesis of functionalized and potentially biologically relevant naphtha[2,3-b]furan-4,9-diones.

Effects of different fertilizers on methane emissions and methanogenic community structures in paddy rhizosphere soil.

Paddy soil accounts for 10% of global atmospheric methane (CH4) emissions. Many types of fertilizers may enhance CH4 emissions, especially organic fertilizer. The aim of this study was to explore the effects of different fertilizers on CH4 and methanogen patterns in paddy soil. This experiment involved four treatments: chemical fertilizer (CT), organic fertilizer (OT), mixed with chemical and organic fertilizer (MT), and no fertilizer (ctrl). The three fertilization treatments were applied with total nitrogen at the same rate of 300 kg N ha-1. Paddy CH4, soil physicochemical variables and methanogen communities were quantitatively analyzed. Rhizosphere soil mcrA and pmoA gene copy numbers were determined by qPCR. Methanogenic 16S rRNA genes were identified by MiSeq sequencing. The results indicated CH4 emissions were significantly higher in OT (145.31 kg ha-1) than MT (84.62 kg ha-1), CT (77.88 kg ha-1) or ctrl (32.19 kg ha-1). Soil organic acids were also increased by organic fertilization. CH4 effluxes were significantly and negatively related to mcrA and pmoA gene copy numbers, and positively related to mcrA/pmoA. Above all, hydrogenotrophic Methanocella and acetoclastic Methanosaeta were the predominant methanogenic communities; these communities were strictly associated with soil potassium, oxalate, acetate, and succinate. Application of organic fertilizer promoted the dominant acetoclastic methanogens, but suppressed the dominant hydrogenotrophic methanogens. The transformation in methanogenic community structure and enhanced availability of C substrates may explain the increased CH4 production in OT compared to other treatments. Compared to OT, MT may partially mitigate CH4 emissions while guaranteeing a high rice yield. On this basis, we recommend the local fertilization pattern should change from 300 N kg ha-1 of organic manure to the same level of mixed fertilization. Moreover, we suggest multiple combinations of mixed fertilization merit more investigation in the future.