To analyze the relationship between nanoparticles and the chemical forms in an urban atmospheric environment, metallic particles with different diameters were collected using a nanoparticle sampling system and analyzed for chemical and morphological characteristics, bioactivity, and the risk of carcinogenic and non-carcinogenic effects. The source of the atmospheric particles was analyzed based on the enrichment factor method, and the carcinogenicity of the atmospheric particles was analyzed using the health risk model. The partition contents of metals extractable by a weak acid, including As, Ca, Cd, Cs, Pb, Sr, and Zn, were in a range of 32.17–71.4%, with an average value of 47.07%. The content of oxides and reducible metals of all of the elements was generally low. Potassium was distributed mainly in the residual and weak-acid-extractable fractions. Barium had a high proportion of the oxidation state. Each fraction of Zn was basically the same, while the content of the weak-acid-extractable fraction was slightly higher. We found bio-access potential to be positively correlated with a high proportion of the weak acid extracts such as Mg, Sr, and Zn. We also found there to be a large weak-acid-extractable fraction (F1) and residual fraction (F4) and relatively enriched elements and strongly enriched elements, which means F1 and F4 may be the cause of enrichment. The hazard index (HI) and the total cancer risk (TCR) were far beyond the safety threshold when the diameter of the particle was in the range of 0.1–0.5 μm, indicating that the residents in Dongguan city were experiencing obvious non-carcinogenic and carcinogenic risks.

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The ring closure of 2‐iodo diaryl ether in the presence of a palladium catalyst to xanthone under carbon monoxide atmosphere is studied. A series of xanthones could be successfully obtained through this protocol, with Pd(OAc)2 as the catalyst, P(Cy)3 as ligand, PivONa.H2O as base, and PivOH and tetrabutylamonium bromide as additives in DMSO, in moderate to good yields.

An efficient palladium catalyzed C−H bond activation for the synthesis of benzo[c]chromen-6-ones using diazonium salts is described. In the presence of Pd(OAc) 2 , dppp, PivOH and K 2 CO 3 , the diazonium salt can be transformed into the product through a denitrogenation/C−H bond activation/cyclization sequence in acetonitrile. Altogether, nine structurally diverse substituted benzo[c]chromen-6-ones were prepared in excellent yields through two different methods.