Kinetics of the ring‐opening metathesis polymerization of a 7‐oxanorbornene derivative by Grubbs' catalyst

Abstract

The kinetics of the initiation and propagation of the ring-opening metathesis polymerization of exo, exo-5,6-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hept-2-ene catalyzed by Grubbs' catalyst (Cl 2 (PCy 3 ) 2 RuACHPh) were measured by ultravioletvisible and 1 H NMR spectroscopy, respectively. Activation parameters for these processes were also determined. Although the ratio of the rate constant of initiation to the rate constant of propagation was determined to be less than 1 for this system, this polymerization showed many of the characteristics of a living system, including low polydispersities. EXPERIMENTALAll manipulations were carried out under an inert nitrogen atmosphere with standard Schlenk and

Synthesis of Comb Tri‐ and Tetrablock Copolymers Catalyzed by the Grubbs First Generation Catalyst

“…[2,31,34] The first step in their synthesis is the Diels-Alder reaction between furan and maleic anhydride. This reaction is very clean, and the product forms crystals of the exo-Diels-Alder adduct at room temperature.…”

“…[1][2][3][4][5][6][7][8][9] Of the many metathesis catalysts reported in the literature, the Grubbs first, second, and third generation catalysts are the most widely used because of their wide functional group tolerance and high activities. The Grubbs first generation catalyst is the most common choice for ROMP, but its activity is much lower than that of the second or third generation catalyst.…”

“…The monomers used in these studies were based on crystallizable exo-oxanorbornenes, and over a hundred grams were synthesized in two simple steps that required no chromatography or distillations. [2,34] These monomers were readily reacted to yield more complex molecules that displayed initiators for atom transfer radical polymerizations. These tri-and tetrablock copolymers were further used to synthesize comb block copolymers that assembled in the solid state into ordered arrays.…”

Effect of the Halide Counterion in the ROMP of exo‐Benzyl‐[2‐(3,5‐dioxo‐10‐oxa‐4‐aza‐tricyclo[5.2.1.02,6]dec‐8‐en‐4‐yl)ethyl]dimethyl ammonium Bromide/Chloride

“…The slope of the pseudo first order plot is equal to k p [Ru] and thus k p is readily calculated. The calculated k p values lie in the range 0.243–0.288 L · mol −1 × s which are consistent with the values we23 and others27 have reported for exo ‐7‐oxanorbornene derivatives. All these data are consistent with controlled polymerizations.…”

Ring Opening Metathesis Polymerization

“…Studies [31,32] considered the ring opening metathesis polymerization as pseudo first-order reaction as regards to the monomer concentration, which is valid for polymerization of abovementioned monomers. The second one is the straight-line segment prolongs to the extent of 70% monomer conversion (till one on the logarithmic scale, Figure 5(b)).…”