Synthesis and ethylene oligomerization behavior of trinuclear nickel complex with phosphorus dendrimer

Author(s):  
Lijun Guo ◽  
Jin Huang ◽  
Na Chen ◽  
Yue Hu ◽  
Miao Li ◽  
...  
2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Jun Wang ◽  
Guang Yang ◽  
Cui-Qin Li ◽  
Wei-Guang Shi ◽  
Si-Han Wang

AbstractA novel nickel metallodendrimer was synthesized with poly(amidoamine), 3,5-di-tert-butyl-2-hydroxy-benzaldehyde and nickel chloride via the Schiff’s base and the complexation reactions. Structures of the dendritic ligand and its nickel complex were characterized by IR, NMR, UV, ESI-MS and elemental analyses. This new nickel metallodendrimer as a catalyst precursor, together with methylaluminoxane as an activator, was evaluated in the ethylene oligomerization. Under the conditions of 0.5 h, 0.5 MPa, 25°C and Al/Ni mole ratio 500: 1 employed for the nickel complex, the catalytic activity showed a maximum value of 4.93 × 105 grams per mole of Ni catalyst per hour. Substituents on the benzene ring seem to have a negative influence on the catalytic activity of the complex.


2019 ◽  
Vol 97 (4) ◽  
pp. 296-302
Author(s):  
Jun Wang ◽  
Junyi Xie ◽  
Libo Wang ◽  
Yan Jiang ◽  
Na Zhang

A salen nickel complex has been prepared in good yield with ethylenediamine, salicylaldehyde, and NiCl2·6H2O as raw materials. The structure of the complex was characterized by FTIR, 1H NMR, UV, and ESI-MS. Upon activation with methylaluminoxane (MAO), the precatalyst showed high activity for ethylene oligomerization. To reduce the simultaneous production of insoluble polymers during the nickel-catalyzed ethylene oligomerization, a series of phenolic compounds were introduced as modifiers for the production of linear α-olefins. The researched result showed that the phenolic compounds have a significant impact on the selectivity of oligomers and the concentration of polymers. With the increase of phenolic compounds, the content of polymers decreased and the distribution of oligomers gradually shifted toward lighter olefins. The sterically hindered 4-tert-butyphenol proved to be an especially efficient polymer-retarding modifier among the studied phenolic compounds in this work. Furthermore, the retarding effect of phenolic compounds toward insoluble polymers may be mainly related to their interaction with MAO, giving rise to larger MAO aggregates.


2020 ◽  
Author(s):  
Shogo Mori ◽  
Takahiro Aoki ◽  
Kaliyamoorthy Selvam ◽  
Shunichi Fukuzumi ◽  
Jieun Jung ◽  
...  

Despite the continuing popularity of radical reactions in organic synthesis, much remains to be explored in this area. Herein, we describe how spatiotemporal control can be exerted over the formation and reactivity of divergent exchangeable formamide radicals using nickel complexes with a semiconductor material (TiO<sub>2</sub>) under irradiation from near-UV–Vis light. Depending on the bipyridine ligand used and the quantity of the nickel complex that is hybridized on or nonhydridized over the TiO<sub>2</sub> surface, these radicals selectively undergo substitution reactions at the carbon center of carbon–bromine bonds that proceed via three different pathways. As the scalable production of formamides from CO<sub>2</sub> does not produce salt waste, these methods could add a new dimension to the search for carbon neutrality through the indirect incorporation of CO<sub>2</sub> into organic frameworks.


2019 ◽  
Author(s):  
Swaraj Sengupta ◽  
Sahanwaj Khan ◽  
Shyamal K. Chattopadhyay ◽  
Indrani Banerjee ◽  
Tarun K. Panda ◽  
...  

Synthesis and characterisation of one trinuclear copper complex, ([Cu<sub>3</sub>L<sub>3</sub>O]ClO<sub>4</sub>) (<b>1</b>) and one nickel complex ([Ni(L'H)<sub>2</sub>(dmso)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>) (<b>2</b>) with Schiff base ligands: (3Z)-3-((Z)-(1-(thiophen-2-yl)ethylidene)hydrazono)butan-2-one oxime (LH) and 1-(pyridin-2-yl)ethylidene)hydrazono)butan-2-one oxime (L<sup>'</sup>H). <b>1</b> shows high catecholase activity and has also been tested as a catalyst for the synthesis of benzylimine. <b>2 </b> shows phenoxazinone synthase activity.


RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22849-22858
Author(s):  
Saroj Kumar Kushvaha ◽  
Maria Francis ◽  
Jayasree Kumar ◽  
Ekta Nag ◽  
Prathap Ravichandran ◽  
...  

A robust tetrameric nickel complex [Ni4((Oal−)2L-Me)4(s)4] (s = solvent) with cubane-like Ni4O4 core topology identified as the efficient catalyst for the diastereoselective cyclopropanation of aromatic heterocycles.


Author(s):  
Chen Hu ◽  
Qing-Qing Huang ◽  
Haibing Xu ◽  
Yuexing Zhang ◽  
Xu Peng ◽  
...  

The availability of polymorphs of metallic complexes provides an opportunity to reveal the relationship between crystal packing and catalytic activity. Herein, we immobilize two stable concomitant polymorphs (green NiL2-G and...


Sign in / Sign up

Export Citation Format

Share Document