The reaction of Cl radicals with bis (2-ethylhexyl) sebacate (also known as dioctyl sebacate, DOS) particles in the presence of O(2) is studied as a model of radical-initiated oxidation of organic aerosols. The uptake coefficient as measured from the rate of loss of DOS is gamma(DOS) = 1.7 (+/-0.3) indicating that a radical chain is operative. It is observed that nearly all of the detected products, accounting for 86% (+/-12%) of the reacted DOS, remain in the particles indicating that they are not efficiently volatilized. Correspondingly, the particles do not decrease in volume even after 60% of the DOS has reacted; upon further reaction the volume does decrease by up to 20%. Additionally, the mass of a DOS film increases with reaction indicating that the density increases. The two primary products identified are the ketone (38 +/- 10% yield) and alcohol (14 +/- 4% yield) resulting from reactions of alkylperoxy radicals originating from DOS oxidation. The fact that the ketone/alcohol ratio is >1 implies that the Russell mechanism, the typical fate of alkylperoxy radicals in liquids whereby both a ketone and an alcohol are generated, is not the only source of ketones. In fact, the ketone yield demonstrates a Langmuir-Hinshelwood type dependence on the O(2) concentration indicating that 44% (+/-8%) of the ketone is created from the reaction of alkoxy radicals with O(2) at the surface of the particles (at 20% O(2)). While this is a common reaction in the gas phase, it is generally not considered to occur in organic solvents. Furthermore, the appearance of gas-phase H(2)O(2) suggests that peroxy radicals react to form two ketones and H(2)O(2)via the Bennett and Summers mechanism. The absence of aldehyde products, both in the gas phase and in the particles, indicates that beta-scission of the alkoxy radicals is not significant. The results of this study suggest that organic aerosols in the troposphere are efficiently oxidized by gas-phase radicals but that their chemical transformation does not lead to their removal through volatilization.

A novel strategy for aromatic trifluoromethylation by converting aromatic amino group into CF3 group is reported herein. This method, which can be considered as trifluoromethylation variation of the classic Sandmeyer reaction, uses readily available aromatic amines as starting materials and is performed under mild conditions.

Hydroxyl radicals (•OH) exert a strong impact on the carbon cycle due to their nonselective and highly oxidizing nature. Reduced iron-containing clay minerals (RIC) are one of the major contributors to the formation of •OH in dark environments, but their interactions with humic acids (HA) are poorly known. Here, we investigate the mutual interactions between RIC and HA under dark and oxygenated conditions. HA decreased the oxidation rate of structural Fe(II) in RIC but significantly promoted the •OH yield. HA dissolved a fraction of Fe(II) from RIC to form an aqueous Fe(II)−HA complex. •OH were generated through both heterogeneous (through oxidation of structural Fe(II)) and homogeneous pathways (through oxidation of aqueous Fe(II)−HA species). RIC-mediated •OH production by providing H 2 O 2 to react with Fe(II)−HA and electrons to regenerate Fe(II)−HA. This highly efficient homogeneous pathway was responsible for increased •OH yield. Abundant •OH significantly decreased the molecular size, bleached chromophores, and increased the oxygen-containing functional groups of HA. These molecular changes of HA resembled photochemical transformation of HA. The mutual interaction between RIC and HA in dark and redoxfluctuating environments provides a new pathway for fast turnover of recalcitrant organic matters in clay-and HA-rich ecosystems such as tropical forest soils and tidal marsh sediments.

Core–shell Pd@Ag nanoparticles are formed within the pores of MOFs via a seed mediated growth strategy with activated hydrogen atoms as the reducing agent, leading to a family of bimetallic core–shell MOF nanomaterials with excelling catalytic performance in room temperature reactions.

The reaction of β-Co(OH)2 hexagonal platelets with graphite oxide in an aqueous colloidal dispersion results in the formation of β-Co(OH)2 hexagonal rings anchored to graphene oxide layers. The interaction between the basic hydroxide layers and the acidic groups on graphene oxide induces chemical etching of the hexagonal platelets, forming β-Co(OH)2 hexagonal rings. On heating in air or N2, the hydroxide hybrid is morphotactically converted to porous Co3O4/CoO hexagonal ring-graphene hybrids. Porous NiCo2O4 hexagonal ring-graphene hybrid is also obtained through a similar process starting from β-Ni0.33Co0.67(OH)2 platelets. As electrode materials for supercapacitors or lithium-ion batteries, these materials exhibit a large capacity, high rate capability, and excellent cycling stability.

Doping of nitrogen into MnO2 is employed as an efficient catalyst for the catalytic oxidation of HMF to DFF under an oxygen atmosphere.

A new kind of metal-free catalyst comprised of highly graphitized N-doped nanoporous carbons from direct carbonization of metal–organic frameworks (MOFs) turns out to be an excellent metal-free catalyst for a series of liquid-phase oxidation reactions including aerobic oxidations of cyclohexane and toluene as well as oxidative coupling of amines.

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