Ring Opening Metathesis Polymerization of Norbornene by WCl6: Formation of WCl5 and WCl4 and Their Catalytic Activity

1996 ◽  
Vol 61 (9) ◽  
pp. 1353-1359 ◽  
Author(s):  
Hynek Balcar ◽  
Zdeněk Bastl

Reaction between WCl6 and norbornene in benzene and cyclohexane, respectively, was investigated using UV/VIS, ESR and XPS spectroscopy in order to establish the main reaction products on the tungsten side and their relation to the initiation of ring opening metathesis polymerization (ROMP) of norbornene. The tungsten compounds: WCl5, insoluble WCl4 and soluble tungsten species having four chlorine atoms bound to tungsten, [WCl4Ln] were found to be the main products. The catalytic activity of the respective compounds in ROMP of norbornene was found to decrease in the order: WCl5 > WCl6 >> WCl4 ~ [WCl4Ln]. The polynorbornenes prepared with both WCl4 and [WCl4Ln] possess higher content of cis double bonds in comparison with polymers prepared with WCl6 and WCl5 catalysts.

2019 ◽  
Author(s):  
François Quintin ◽  
Julien Pinaud ◽  
Frédéric Lamaty ◽  
Xavier Bantreil

The use of ball-mills enabled the efficient mechanosynthesis of a variety of N-aryl,N-alkyl imidazolium salts and of corresponding NHC-silver(I) complexes. Transmetalation with ruthenium via mechanochemistry allowed the rapid access (1.5 min to 1 h) to complexes having a similar structure to Noels-type precatalysts. Evaluation of the complexes in the Ring-Opening Metathesis Polymerization of norbornene in different solvent, including non-toxic ones, showed a high catalytic activity for one of them, comparable to the one of Noels catalyst.<br>


2019 ◽  
Vol 15 ◽  
pp. 44-51 ◽  
Author(s):  
Yuan-Zhen Ke ◽  
Shou-Ling Huang ◽  
Guoqiao Lai ◽  
Tien-Yau Luh

At 0 °C in THF in the presence of Grubbs first generation catalyst, cyclobutene derivatives undergo ROMP readily, whereas norbornene derivatives remain intact. When the substrate contains both cyclobutene and norbornene moieties, the conditions using THF as the solvent at 0 °C offer a useful protocol for the selective ROMP of cyclobutene to give norbornene-appended polycyclobutene. Unsymmetrical ladderphane having polycyclobutene and polynorbornene as two strands is obtained by further ROMP of the norbornene appended polycyclobutene in the presence of Grubbs first generation catalyst in DCM at ambient temperature. Methanolysis of this unsymmetrical ladderphane gives polycyclobutene methyl ester and insoluble polynorbornene-amide-alcohol. The latter is converted into the corresponding soluble acetate. Both polymers are well characterized by spectroscopic means. No norbornene moiety is found to be incorporated into polycyclobutene strand at all. The double bonds in the polycyclobutene strand are mainly in cis configuration (ca 70%), whereas the E/Z ratio for polynorbornene strand is 8:1.


2019 ◽  
Author(s):  
François Quintin ◽  
Julien Pinaud ◽  
Frédéric Lamaty ◽  
Xavier Bantreil

The use of ball-mills enabled the efficient mechanosynthesis of a variety of N-aryl,N-alkyl imidazolium salts and of corresponding NHC-silver(I) complexes. Transmetalation with ruthenium via mechanochemistry allowed the rapid access (1.5 min to 1 h) to complexes having a similar structure to Noels-type precatalysts. Evaluation of the complexes in the Ring-Opening Metathesis Polymerization of norbornene in different solvent, including non-toxic ones, showed a high catalytic activity for one of them, comparable to the one of Noels catalyst.<br>


2015 ◽  
Vol 6 (42) ◽  
pp. 7418-7426 ◽  
Author(s):  
Wen-Ke Miao ◽  
Ang Yi ◽  
Yu-Kun Yan ◽  
Li-Jun Ren ◽  
Da Chen ◽  
...  

A poly(polyoxometalate)-polymer hybrid block copolymer (H-BCP) was prepared via ring-opening metathesis polymerization (ROMP). The H-BCP self-assembles into hybrid micelles with a poly(polyoxometalate) shell and a polymer core in acetonitrile.


2011 ◽  
Author(s):  
Robert H. Lambeth ◽  
Joseph M. Dougherty ◽  
Joshua A. Orlicki ◽  
Adam M. Rawlett ◽  
Robert C. Hoffman ◽  
...  

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