Abstract
The synthesis and characterization of the bimetallic 2,7-di-[(2,6- diisopropylphenyl)imino]-1,8- naphthalenediolato group 10 metal polymerization catalysts {[Ni(CH 3)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6- Pr 2C 6H 3)](PMe 3) 2} and {[Ni(1-naphthyl)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6-Pr 2C 6H 3)](PPh 3) 2} [FI 2-Ni 2(PR 3) 2] are presented, along with the synthesis and characterization of the mononuclear analogues {Ni(CH 3)[3- tBu- 2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PMe) 3}and{Ni(1-naphthyl)[3- tBu-2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PPh) 3}[FI- Ni (PR 3)]. Monometallic Ni catalysts were also prepared by functionalizing one ligation center of the bimetallic ligand with a trimethylsilyl group (TMS), yielding {Ni(CH 3)[1,8-(O)(TMSO)C 10H 4-2,7-[CH=N(2,6- iPr 2C 6H 3)](PMe 3)} [TMS-FI 2-Ni(PMe 3)]. The Fl 2-Ni 2 catalysts exhibit significant increases in ethylene homopolymerization activity versus the monometallic analogues, as well as increased branching and methyl branch selectivity, even in the absence of a Ni(cod) 2 cocatalyst. Increasing ethylene concentrations significantly suppress branching and alter branch morphology. FI 2-Ni 2-mediated copolymerizations with ethylene + polar-functionalized norbornenes exhibit a 4-fold increase in comonomer incorporation versus Fl-Ni, yielding copolymers with up to 10% norbornene copolymer incorporation. FI 2-Ni 2-catalyzed copolymerizations with ethylene + methylacrylate or methyl methacrylate incorporate up to 11% acrylate comonomer, while the corresponding mononuclear Fl-Ni catalysts incorporate negligible amounts. Furthermore, the FI 2-Ni 2-mediated polymerizations exhibit appreciable polar solvent tolerance, turning over in the presence of ethyl ether, acetone, and even water. The mechanism by which the present cooperative effects take place is investigated, as is the nature of the copolymer microstructures produced.
| Original language | English |
|---|---|
| Pages (from-to) | 5902-5919 |
| Number of pages | 18 |
| Journal | Journal of the American Chemical Society |
| Volume | 131 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - Apr 29 2009 |
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ASJC Scopus subject areas
- Chemistry(all)
- Catalysis
- Biochemistry
- Colloid and Surface Chemistry
Cite this
Bimetallic effects for enhanced polar comonomer enchainment selectivity in catalytic ethylene polymerization. / Rodriguez, Brandon A.; Delferro, Massimiliano; Marks, Tobin J.
In: Journal of the American Chemical Society, Vol. 131, No. 16, 29.04.2009, p. 5902-5919.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Bimetallic effects for enhanced polar comonomer enchainment selectivity in catalytic ethylene polymerization
AU - Rodriguez, Brandon A.
AU - Delferro, Massimiliano
AU - Marks, Tobin J
PY - 2009/4/29
Y1 - 2009/4/29
N2 - The synthesis and characterization of the bimetallic 2,7-di-[(2,6- diisopropylphenyl)imino]-1,8- naphthalenediolato group 10 metal polymerization catalysts {[Ni(CH 3)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6- Pr 2C 6H 3)](PMe 3) 2} and {[Ni(1-naphthyl)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6-Pr 2C 6H 3)](PPh 3) 2} [FI 2-Ni 2(PR 3) 2] are presented, along with the synthesis and characterization of the mononuclear analogues {Ni(CH 3)[3- tBu- 2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PMe) 3}and{Ni(1-naphthyl)[3- tBu-2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PPh) 3}[FI- Ni (PR 3)]. Monometallic Ni catalysts were also prepared by functionalizing one ligation center of the bimetallic ligand with a trimethylsilyl group (TMS), yielding {Ni(CH 3)[1,8-(O)(TMSO)C 10H 4-2,7-[CH=N(2,6- iPr 2C 6H 3)](PMe 3)} [TMS-FI 2-Ni(PMe 3)]. The Fl 2-Ni 2 catalysts exhibit significant increases in ethylene homopolymerization activity versus the monometallic analogues, as well as increased branching and methyl branch selectivity, even in the absence of a Ni(cod) 2 cocatalyst. Increasing ethylene concentrations significantly suppress branching and alter branch morphology. FI 2-Ni 2-mediated copolymerizations with ethylene + polar-functionalized norbornenes exhibit a 4-fold increase in comonomer incorporation versus Fl-Ni, yielding copolymers with up to 10% norbornene copolymer incorporation. FI 2-Ni 2-catalyzed copolymerizations with ethylene + methylacrylate or methyl methacrylate incorporate up to 11% acrylate comonomer, while the corresponding mononuclear Fl-Ni catalysts incorporate negligible amounts. Furthermore, the FI 2-Ni 2-mediated polymerizations exhibit appreciable polar solvent tolerance, turning over in the presence of ethyl ether, acetone, and even water. The mechanism by which the present cooperative effects take place is investigated, as is the nature of the copolymer microstructures produced.
AB - The synthesis and characterization of the bimetallic 2,7-di-[(2,6- diisopropylphenyl)imino]-1,8- naphthalenediolato group 10 metal polymerization catalysts {[Ni(CH 3)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6- Pr 2C 6H 3)](PMe 3) 2} and {[Ni(1-naphthyl)] 2[1,8-(O) 2C 10H 4-2,7-[CH=N(2,6-Pr 2C 6H 3)](PPh 3) 2} [FI 2-Ni 2(PR 3) 2] are presented, along with the synthesis and characterization of the mononuclear analogues {Ni(CH 3)[3- tBu- 2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PMe) 3}and{Ni(1-naphthyl)[3- tBu-2-(0)C 6H 3CH=N(2,6- iPr 2C 6H 3)](PPh) 3}[FI- Ni (PR 3)]. Monometallic Ni catalysts were also prepared by functionalizing one ligation center of the bimetallic ligand with a trimethylsilyl group (TMS), yielding {Ni(CH 3)[1,8-(O)(TMSO)C 10H 4-2,7-[CH=N(2,6- iPr 2C 6H 3)](PMe 3)} [TMS-FI 2-Ni(PMe 3)]. The Fl 2-Ni 2 catalysts exhibit significant increases in ethylene homopolymerization activity versus the monometallic analogues, as well as increased branching and methyl branch selectivity, even in the absence of a Ni(cod) 2 cocatalyst. Increasing ethylene concentrations significantly suppress branching and alter branch morphology. FI 2-Ni 2-mediated copolymerizations with ethylene + polar-functionalized norbornenes exhibit a 4-fold increase in comonomer incorporation versus Fl-Ni, yielding copolymers with up to 10% norbornene copolymer incorporation. FI 2-Ni 2-catalyzed copolymerizations with ethylene + methylacrylate or methyl methacrylate incorporate up to 11% acrylate comonomer, while the corresponding mononuclear Fl-Ni catalysts incorporate negligible amounts. Furthermore, the FI 2-Ni 2-mediated polymerizations exhibit appreciable polar solvent tolerance, turning over in the presence of ethyl ether, acetone, and even water. The mechanism by which the present cooperative effects take place is investigated, as is the nature of the copolymer microstructures produced.
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U2 - 10.1021/ja900257k
DO - 10.1021/ja900257k
M3 - Article
VL - 131
SP - 5902
EP - 5919
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 16
ER -