Control over Selectivity in Alkene Hydrosilylation Catalyzed by Cobalt(III) Hydride Complexes.

Two new bisphosphine [PCP] pincer cobalt(III) hydrides, [(L)Co(PMe)(H)(Cl)] (, = 2,6-((PhP)(Et)N)CH) and [(L)Co(PMe)(H)(Cl)] (, = 2,6-((PrP)(Et)N)CH), as well as one new bissilylene [SiCSi] pincer cobalt(III) hydride, [(L)Co(PMe)(H)(Cl)] (, = 1,3-((PhC(BuN)Si)(Et)N)CH), were synthesized by reaction of the corresponding protic [PCP] or [SiCSi] pincer ligands , and with CoCl(PMe). Despite the similarities in the ligand scaffolds, the three cobalt(III) hydrides show remarkably different performance as catalysts in alkene hydrosilylation. Among the PCP pincer complexes, has higher catalytic activity than complex , and both catalysts afford -Markovnikov selectivity for both aliphatic and aromatic alkenes.

[Emission Inventory of Greenhouse Gas from Urban Wastewater Treatment Plants and Its Temporal and Spatial Distribution in China].

Urban wastewater treatment plants are considered important greenhouse gas resources with massive emissions of carbon dioxide (CO), methane (CH), and nitrous oxide (NO) during operation. Based on the emission factor approach of pollutant reduction, the 2014 emission inventory of greenhouse gases (CO, CH, and NO) from urban wastewater treatment plants in China was established. In addition, the temporal and spatial distribution and influencing factors of greenhouse gas emissions were analyzed in this study.

Transfer hydrogenation of aldehydes catalyzed by silyl hydrido iron complexes bearing a [PSiP] pincer ligand.

The synthesis and characterization of a series of silyl hydrido iron complexes bearing a pincer-type [PSiP] ligand (2-RPCH)SiH (R = Ph (1) and Pr (5)) or (2-PhPCH)SiMeH (2) were reported. Preligand 1 reacted with Fe(PMe) to afford complex ((2-PhPCH)SiH)Fe(H)(PMe) (3) in toluene, which was structurally characterized by X-ray diffraction. ((2-PrPCH)SiH)Fe(H)(PMe) (6) could be obtained from the reaction of preligand 5 with Fe(PMe) in toluene.

Synthesis and catalytic activity of N-heterocyclic silylene (NHSi) cobalt hydride for Kumada coupling reactions.

The electron-rich silylene Co(i) chloride 5 was obtained through the reaction of CoCl(PMe) with chlorosilylene. Complex 5 reacted with 1,3-siladiazole HSiMe(NCHPPh)CH to give the silylene Co(iii) hydride 6 through chelate-assisted Si-H activation. To the best of our knowledge, complex 6 is the first example of Co(iii) hydride supported by N-heterocyclic silylene.