A rings-in-pores net: crown ether-based covalent organic frameworks for phase-transfer catalysis.

We herein present a new family of crown ether-based covalent organic frameworks (CE-COFs) for the first time. The CE-COFs show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.

Efficient and Recyclable RuCl ⋅ 3HO Catalyst Modified with Ionic Diphosphine for the Alkoxycarbonylation of Aryl Halides.

A series of ionic (mono-/di-)phosphines (, , and ) with structural similarity and their corresponding neutral counterparts (, , and ) were applied to modulate the catalytic performance of RuCl ⋅ 3HO. With the involvement of the ionic diphosphine (), in which the two phosphino-fragments were linked by butylene group, RuCl ⋅ 3HO with advantages of low cost, robustness, and good availability was found to be an efficient and recyclable catalyst for the alkoxycarbonylation of aryl halides. The -based RuCl ⋅ 3HO system corresponded to the best conversion of PhI (96 %) along with 99 % selectivity to the target product of methyl benzoate as well as the good generality to alkoxycarbonylation of different aryl halides (ArX, X=I and Br) with alcohols MeOH, EtOH, -PrOH and -BuOH.

[Distribution Characteristics of Water-soluble Ions in Size-segregated Particulate Matters in Taiyuan].

The distributions of size-segregated particles (PM) and water-soluble ions (WSIs) in Taiyuan were studied from July 2014 to April 2015 by TE-235 aerosol sampling and ion chromatography analyzing. As the results shown, the daily PM level was 173.7 μg·m, which exceeded the Grade Ⅱ limitation value in the Ambient Air Quality Standard (150 μg·m, GB 3095-2012).