A visible light‐induced formation of Aryl‐Phosphorous bonds starting from arylazo sulfones and triaryl (or trialkyl)phosphites in the absence of any photoredox catalyst and any additives was developed. This reaction showed a broad substrate scope and afforded (hetero)aryl phosphonates in good yields and in up to the gram scale.magnified image
A novel Pd/C catalysed direct reductive coupling reaction between nitroarenes and sodium arylsulfinates to synthesize N-arylsulfonamides was developed.
Abstract. An observation-based method (OBM) is developed to
investigate the sensitivity of ozone formation to precursors during two
persistent elevated ozone episodes observed at 77 stations in Guangdong.
Average OH concentrations derived at the 77 stations between 08:00 and 13:00
local time stay within a narrow range of 2.5×106 to
5.5×106 cm−3 with a weak dependence on the NOx. These
values are in good agreement with OH values observed at a rural station in
the Pearl River Delta (PRD). They also agree well with a box model constrained
by the ambient conditions observed during the two episodes. The OBM has been
used to evaluate the ozone production efficiency, ε(NOx or volatile organic compound,
VOC), defined as the number of O3 molecules produced per molecule of
NOx (or VOC) oxidized. Average values of ε(NOx) and
ε(VOC) determined by the OBM are 3.0 and 2.1 ppb ppb−1,
respectively, and both compared well with values in previous studies.
Approximately 67 % of the station days exhibit ozone formation sensitivity
to NOx, and approximately 20 % of the station days are in the
transitional regime sensitive to both NOx and VOC, and only approximately
13 % of the station days are sensitive to VOC. These results are in
semi-quantitative agreement with the ozone formation sensitivity calculated
by the box model constrained by ambient conditions observed during the two
episodes. However, our OBM results differ from those of most previous
investigations, which suggested that limiting the emission of VOC rather than
NOx would be more effective in reducing ozone reduction in Guangdong.
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