Polymerizability of cycloalkenes in a living ring-opening metathesis polymerization initiated by Schrock complexes, 1. Effect of the solvent on the polymerization kinetics

Cazalis, Chrystelle; Héroguez, Valérie; Fontanille, Michel

doi:10.1002/(sici)1521-3935(20000501)201:8<869::aid-macp869>3.3.co;2-q

Cited by 5 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a previous paper, [2] it was established that polymerizations initiated by II are "living" and "controlled". To Table 1 mirror a satisfactory control of the process.…”

Section: Influence Of the Ligandsmentioning

confidence: 99%

“…[2] For an initial monomer concentration [NBE] 0 equal to 8.10 -2 mol/L, the polymerizability of norbornene for processes initiated by II (k p = 33.4 s -1 ) is much higher than that obtained for processes initiated by I (k p, app = 0.7 s -1 ). It can be inferred that the presence of fluorinated alkoxy ligands in complex II increases the electropositive character of the transition metal and, therefore, enhances the coordination of the monomer onto active centers.…”

Section: Influence Of the Ligandsmentioning

confidence: 99%

“…Following a previous study [2] we performed polymerizations of norbornene in cyclohexane, considering that this solvent is inert towards the reactivity of propagating species.…”

Section: Introductionmentioning

confidence: 98%

“…These results were all corroborated by prior theoretical studies using ab initio calculations. [2] metalla-alkylidenic species whose concentration in the reaction medium determines the polymerizability. Previous studies have already been published pertaining to the use of W-or Mo-based Schrock complexes with various alkoxy ligands (OR) as "catalysts" of olefin metathesis.…”

Section: Introductionmentioning

confidence: 99%

“…The ROMP of norbornene initiated by Schrock complexes (Met(CHR9)(NAr)(OR) 2, NAr = Ph (iPr) 2 ) shows all the characteristics of a "living" process (Equation (1)). [1] In a previous paper, [2] the influence of the nature of solvent on the polymerizability of norbornene in ROMP was presented. The kinetics of the ROMP process were studied in three different solvents, and it was established that the actual active centers are monomer-complexed Full Paper: The kinetics of ring-opening metathesis polymerization of norbornene were investigated in cyclohexane using several Schrock complexes as initiators.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Cazalis

Héroguez

Fontanille

2001

Macromol. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

The kinetics of ring‐opening metathesis polymerization of norbornene were investigated in cyclohexane using several Schrock complexes as initiators. Three different Schrock complexes were used: Mo(CHC(CH3)2Ph)(NAr)(O‐t‐Bu)2 (NAr = Ph (iPr) 2) (I), Mo(CHC(CH3)2Ph)(NAr)(OC(CF3)2CH3)2 (NAr = Ph (iPr) 2) (II) and W(CH‐t‐Bu)(NAr)(O‐t‐Bu)2 (NAr = Ph (iPr) 2) (III). The presence of alkoxy‐fluorinated ligands on II and on the corresponding propagating species enhances the polymerizability of norbornene and modifies the kinetic scheme compared to that of polymerizations initiated by the tert‐butoxy complex. The greater electropositive character of II compared to that of I results in a majority of metalla‐alkylidenic growing species being complexed to monomer; therefore, the coordination of the monomer is not the rate‐determining step for the process. In contrast, the major part of growing species, which are derived from the tert‐butoxy complex are in a non‐coordinated state and, thus, the ability of the initiator to complex the monomer is decisive. In addition, this study allows to quantify the stronger reactivity of W‐based complexes compared to that of Mo‐based ones. These results were all corroborated by prior theoretical studies using ab initio calculations.

show abstract

“…In a previous paper, [2] it was established that polymerizations initiated by II are "living" and "controlled". To Table 1 mirror a satisfactory control of the process.…”

Section: Influence Of the Ligandsmentioning

confidence: 99%

Section: Influence Of the Ligandsmentioning

confidence: 99%

“…Following a previous study [2] we performed polymerizations of norbornene in cyclohexane, considering that this solvent is inert towards the reactivity of propagating species.…”

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Cazalis

Héroguez

Fontanille

2001

Macromol. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

Ring‐Opening Polymerization

Odian

2004

Principles of Polymerization

View full text Add to dashboard Cite

A wide variety of cyclic monomers have been successfully polymerized by the ring-opening process [Frisch and Reegan, 1969; Ivin and Saegusa, 1984;Saegusa and Goethals, 1977]. This includes cyclic amines, sulfides, olefins, cyclotriphosphazenes, and N-carboxy-a-amino acid anhydrides, in addition to those classes of monomers mentioned above. The ease of polymerization of a cyclic monomer depends on both thermodynamic and kinetic factors as previously discussed in Sec. 2-5.The single most important factor that determines whether a cyclic monomer can be converted to linear polymer is the thermodynamic factor, that is, the relative stabilities of the cyclic monomer and linear polymer structure [Allcock, 1970;Sawada, 1976]. Table 7-1 shows the semiempirical enthalpy, entropy, and free-energy changes for the conversion of cycloalkanes to the corresponding linear polymer (polymethylene in all cases) [Dainton and Ivin, 1958;Finke et al. 1956]. The lc (denoting liquid-crystalline) subscripts of ÁH, ÁS, and ÁG indicate that the values are those for the polymerization of liquid monomer to crystalline polymer.Polymerization is favored thermodynamically for all except the 6-membered ring. Ringopening polymerization of 6-membered rings is generally not observed. The order of thermodynamic feasibility is 3,4 > 8 > 5,7 which follows from the previous discussion (Sec. 2-5c) on bond angle strain in 3-and 4-membered rings, eclipsed conformational strain in the 5-membered ring, and transannular strain in 7-and 8-membered rings. One notes that RING-OPENING POLYMERIZATION RING-OPENING POLYMERIZATION

show abstract

Polymerization of n‐Octylallene with Rare Earth Catalyst Composed of Ln(P₂₀₄)₃/Al(i‐Bu)₃

Zhu

Shen

2010

Chin. J. Chem.

View full text Add to dashboard Cite

Polymerization of n-octylallene was successfully carried out using a conventional binary rare earth catalytic system composed of rare earth tris(2-ethylhexylphosphonate) (Ln(P 204 ) 3 ) and tri-isobutyl aluminum (Al(i-Bu) 3 ) for the first time. The effects of catalyst, solvent, reaction time and temperature on the polymerization of n-octylallene were studied. The resulting poly(n-octylallene) has weight-average molecular weight of 11000, molecular weight distribution of 1.4 and 96% yield under the moderate reaction conditions: [Al]/[Y] ＝ 50 (molar ratio), [n-octylallene]/[Y]＝100 (molar ratio), polymerized at 80 ℃ for 20 h in bulk. The poly(n-octylallene) obtained consisted of 1,2-and 2,3-polymerized units, and was characterized by FT-IR, 1 H NMR and GPC. Further investigation shows that the polymerization of n-octylallene has some living polymerization characteristics, preparing the polymer with controlled molecular weight and narrower molecular weight distribution.

show abstract

Polymerizability of cycloalkenes in a living ring-opening metathesis polymerization initiated by Schrock complexes, 1. Effect of the solvent on the polymerization kinetics

Cited by 5 publications

References 0 publications

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Ring‐Opening Polymerization

Polymerization of n‐Octylallene with Rare Earth Catalyst Composed of Ln(P₂₀₄)₃/Al(i‐Bu)₃

Contact Info

Product

Resources

About

Polymerizability of cycloalkenes in a living ring-opening metathesis polymerization initiated by Schrock complexes, 1. Effect of the solvent on the polymerization kinetics

Cited by 5 publications

References 0 publications

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Polymerizability of Cycloalkenes in “Living” Ring-Opening Metathesis Polymerization Initiated by Schrock Complexes, 2. Effect of Initiator Structure

Ring‐Opening Polymerization

Polymerization of n‐Octylallene with Rare Earth Catalyst Composed of Ln(P204)3/Al(i‐Bu)3

Contact Info

Product

Resources

About

Polymerization of n‐Octylallene with Rare Earth Catalyst Composed of Ln(P₂₀₄)₃/Al(i‐Bu)₃