692-70-6Relevant articles and documents
Dendrimer-Encapsulated Pd Nanoparticles, Immobilized in Silica Pores, as Catalysts for Selective Hydrogenation of Unsaturated Compounds
Karakanov, Edward A.,Zolotukhina, Anna V.,Ivanov, Andrey O.,Maximov, Anton L.
, p. 358 - 381 (2019/04/04)
Heterogeneous Pd-containing nanocatalysts, based on poly (propylene imine) dendrimers immobilized in silica pores and networks, obtained by co-hydrolysis in situ, have been synthesized and examined in the hydrogenation of various unsaturated compounds. The catalyst activity and selectivity were found to strongly depend on the carrier structure as well as on the substrate electron and geometric features. Thus, mesoporous catalyst, synthesized in presence of both polymeric template and tetraethoxysilane, revealed the maximum activity in the hydrogenation of various styrenes, including bulky and rigid stilbene and its isomers, reaching TOF values of about 230000 h?1. Other mesoporous catalyst, synthesized in the presence of polymeric template, but without addition of Si(OEt)4, provided the trans-cyclooctene formation with the selectivity of 90–95 %, appearing as similar to homogeneous dendrimer-based catalysts. Microporous catalyst, obtained only on the presence of Si(OEt)4, while dendrimer molecules acting as both anchored ligands and template, demonstrated the maximum activity in the hydrogenation of terminal linear alkynes and conjugated dienes, reaching TOF values up to 400000 h?1. Herein the total selectivity on alkene in the case of terminal alkynes and conjugated dienes reached 95–99 % even at hydrogen pressure of 30 atm. The catalysts synthesized can be easily isolated from reaction products and recycled without significant loss of activity.
Palladium nanoparticles encapsulated in a dendrimer networks as catalysts for the hydrogenation of unsaturated hydrocarbons
Karakhanov, Edward A.,Maksimov, Anton L.,Zakharian, Elena M.,Kardasheva, Yulia S.,Savilov, Sergey V.,Truhmanova, Nadezhda I.,Ivanov, Andrey O.,Vinokurov, Vladimir A.
, p. 1 - 18 (2015/02/19)
A novel method has been proposed for encapsulating palladium nanoparticles up to 5 nm in the matrix of polymeric support networks based on polyamidoamine dendrimers. The shape of the particle size distribution and the catalytic activity of the materials obtained during the hydrogenation of unsaturated compounds depend strongly on the support structure. High activity (TOF up to 86,000 h-1) has been observed during the hydrogenation of styrene.
Oligomerization of α-olefins by the dimeric nickel bisamido complex [Ni{1-N(PMes2)-2-N(μ-PMes2)C6H4-κ3N,N′,P,-κ1P′}]2 activated by methylalumoxane (MAO)
Majoumo-Mbe, Felicite,L?nnecke, Peter,Volkis, Victoria,Sharma, Manab,Eisen, Moris S.,Hey-Hawkins, Evamarie
, p. 2603 - 2609 (2008/09/21)
The reaction of Li2[1,2-{N(PMes2)}2C6H4], formed in situ from n-BuLi and the corresponding amines, with 1 equiv. of [NiBr2(DME)] gives [Ni{1-N(PMes2)-2-N(μ-PMes2)C6H4-κ3N,N′,P-κ1P′}]2 (1). After activation by methylalumoxane (MAO), 1 is a highly active catalyst in the oligomerization and isomerization of α-olefins such as ethene, propene, isobutene, 1-hexene and 1,5-hexadiene. For ethene oligomerization turnover frequencies (TOFs) range from 3000 to 79015 h-1, depending on the reaction conditions. The TOF for propene oligomerization reaches 1 190 730 h-1. To our knowledge, catalyst 1, activated by MAO, is the most active catalyst for the oligomerization of propene and outperforms the best known complexes for this reaction. In the reactions with 1-hexene, 1,5-hexadiene and isobutene dimerization and isomerization products were observed.
