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>
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.
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>
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.
Synthesis and catalytic activity of supported acenaphthoimidazolylidene N-heterocyclic carbene ruthenium complex for ring closing metathesis (RCM) and ring opening metathesis polymerization (ROMP)