N -decorated porous carbon (NDC) was obtained by one step direct pyrolysis of NH 2 -MIL-125. The content of nitrogen in the NDC-1000 (2 h) was 4.2%. Palladium nanoparticle was deposited on the NDC by an impregnation strategy. The NDC-1000-Pd catalyst was characterized by powder X-ray diffraction, TEM, XPS and N 2 adsorption. Due to the synergetic interaction of metal species and NDC, the catalyst exhibited excellent catalytic performance for Heck coupling and Suzuki-Miyaura reactions. The catalyst can be reused for five cycles without obvious change in its activity.
Yuhan Wei,Lei Xu,Shengjiao He,Chenglei Li,Qi Wu,Xianyin Zeng,Hanguang Wang,Kuan Liu
Two benzimidazole-based conjugated polyelectrolytes (+)-PPBIPV and (-)-PPBIPV which have opposite charges on their side chains were synthesized via Heck coupling reaction and characterized by 1 H-NMR, UV-vis and PL spectroscopy. These two polyelectrolytes are both consisted of benzimidazole derivatives and phenylenevinylene units. The absorption and emission spectra reveal that the polymers both have solvent-dependency and concentration-dependency, and they exhibit aggregation effect in aqueous solution. In the respect of ion detection, the aqueous solution of (+)-PPBIPV has excellent selectivity and sensitivity for Fe 3+ . Moreover, Pd 2+ can almost completely quench the fluorescence of (+)-PPBIPV in methanol solution, and its quenching constant K SV is 5.93×10 4 M -1 . For (-)-PPBIPV, Sn 2+ can double the fluorescence intensity of its aqueous solution, while (-)-PPBIPV has good identification for Fe 3+ in methanol with a K SV = 3.44×10 5 M -1 . Hence, two polyelectrolytes have considerable potential to become effective fluorescent sensing materials for some specific metal ions. All of the stoichiometric relationships between metal ions and conjugated polyelectrolytes were calculated using Benesi-Hildebrand equation.
A novel and environmentally friendly heterogeneous catalyst has been prepared through the wet impregnation of copper(I) species onto the highly porous chitosan microspheres (CuI/PCMS). This novel CuI/PCMS heterogeneous catalyst with no additional ligands is much better than CuI homogeneous catalysts when applied in Heck reactions. Moreover, the reaction conditions are much milder than those for the similar copper catalysts mediated cross-coupling reactions reported in the literature. PCMS has been demonstrated not only the excellent solid support, but also have many unique functional groups to chelate the copper (I) species to enhance its catalytic activity.
Two novel Pd-loaded heteroatom-linked microporous polymers Pd@NP and Pd@NPO were effectively synthesized by one-pot Pd-catalyzed Heck coupling reactions of tris(4-vinylphenyl)amine with tris(4-bromophenyl)phosphine and tris(4-bromophenyl)phosphine oxide, respectively. The Pd atoms loaded into the networks of the resulting porous polymers originated from the Pd-catalyst used in the polymerization, which was achieved under moderate reaction conditions. Besides the nitrogen atoms, the trivalent phosphorus atoms bearing one lone pair of electrons and the pentavalent phosphorus atoms of the phosphoryl groups were used as the linkers for the formation of the frameworks of the porous polymers Pd@NP and Pd@NPO, respectively. The phosphorus atoms with different oxidation states in the networks caused a dramatic variation in the physical and catalytic properties of the as-prepared porous polymers. Pd@NP and Pd@NPO exhibit surface areas of 381 m2 g−1 and 684 m2 g−1, respectively. Both Pd-loaded porous polymers enable efficient Suzuki–Miyaura coupling reactions featuring short reaction times and good yields, with the catalysts being highly stable and easy to recycle. The catalytic activity of Pd@NPO is higher than that of Pd@NP.
危险品化学品经营许可证（带存储）