Ultimately Specific 1,4‐cis Polymerization of 1,3‐Butadiene with a Novel Gadolinium Catalyst

Kaita, Shojiro; Hou, Zhaomin; Nishiura, Masayoshi; Doi, Yoshiharu; Kurazumi, Junko; Horiuchi, Akira; Wakatsuki, Yasuo

doi:10.1002/marc.200390031

Cited by 112 publications

(63 citation statements)

References 15 publications

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“…[86] Further evidence that cationic hydrocarbyl complexes act as the active species is given by the following observation: The activation of the cationic bis(pentamethylcyclopentadienyl) complexes [LnCp* 2 ][B(C 6 F 5 ) 4 ] (Ln ¼ Pr, Nd, Sm) with Al(i-Bu) 3 was reported to afford highly cis-1,4 selective initiators for 1,3-butadiene polymerization (Table 7). [12,83,87] The above findings may also imply that, in the case of the industrially applied multicomponent catalysts typically consisting of lanthanide carboxylate, aluminum alkyl and Lewis acid, discrete cationic alkyl species may be formed in situ or exist in equilibrium with non-ionic compounds (Scheme 14). [88,89] …”

Section: Polymerization Of Ethylene and A-olefinsmentioning

confidence: 98%

Cationic Alkyl Complexes of the Rare‐Earth Metals: Synthesis, Structure, and Reactivity

2005

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This contribution is dedicated to Dick Schrock on the occasion of his 60th birthday.Abstract: Cationic alkyl complexes of the rare-earth metals [LnR m ; L ¼ Lewis base) were virtually unknown species until recently. Because of their increased Lewis acidity/electrophilicity they should have considerable potential as homogeneous catalysts in olefin polymerization and in organic transformations. They can be generated by treating the neutral rare-earth metal precursors containing at least two alkyl groups R with suitable Lewis or Brønsted acids in the presence of weakly coordinating anions. Not only monocationic but also dicationic alkyl derivatives have been shown to be accessible. In the context of modeling homogeneous ethylene polymerization using a mixture consisting of LnR 3 /AlR 3 /[NMe 2 HPh][B(C 6 F 5 ) 4 ], such dications were discovered. Some thermally robust examples of mono-and dicationic alkyl complexes have been structurally characterized as solvent-separated ion pairs. Neutral and monoanionic macrocycles such as crown ethers or aza-crown ethers as well as amidinato, b-diketiminato, and substituted cyclopentadienyl ligands are suitable ancillary ligands to stabilize the cationic alkyl fragments.

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Section: Polymerization Of Ethylene and A-olefinsmentioning

confidence: 98%

Cationic Alkyl Complexes of the Rare‐Earth Metals: Synthesis, Structure, and Reactivity

2005

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“…The 1 H-NMR spectra of all BR sample (Fig. 2a) showed the signals at a chemical shift (d) of 4.8-5.2 ppm for @CH 2 of vinyl21,2 configurations and 5.2-5.8 ppm for -CH@ of 1,4-butadiene and 1,2-butadiene units [11]. It was found that the Nd-BR and Co/Nd-BR exhibited lower signals for @CH 2 of vinyl21,2 structure than Co-BR.…”

Section: Resultsmentioning

confidence: 98%

1,3‐butadiene polymerization using Co/Nd‐based Ziegler/Natta catalyst: Microstructures and properties of butadiene rubber

Chatarsa

Prasassarakich

Rempel

et al. 2014

Polymer Engineering & Sci

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Among Ziegler‐Natta catalysts used for 1,3‐butadiene (1,3‐BD) polymerization, the advantage of a neodymium (Nd)‐based catalyst is that it provides butadiene rubber (BR) with a high content of cis−1,4 configuration and a low amount of vinyl−1,2 units. Whereas, a cobalt (Co)‐based catalyst can produce BR with a low content of trans−1,4 configuration. Thus, this research was aimed to prepare BR containing a high content of cis−1,4 configuration with low amounts of both trans−1,4 and vinyl−1,2 units using a combination of Nd‐ and Co‐based Ziegler/Natta catalysts with triethyl aluminum (TEAL) and diethyl aluminum chloride (DEAC) acting as a co‐catalyst and a chlorinating agent, respectively. The effects of the molar Co/Nd ratio, TEAL concentration, DEAC loading, 1,3‐BD content, solvent type, and reaction temperature on % conversion, microstructures, molecular weight, and molecular weight distribution of the obtained BR (Co/Nd‐BR) were evaluated. The Co/Nd‐BR having >97% of cis−1,4 configuration, <2% of trans−1,4 structure, and <1% of vinyl−1,2 unit with >80% conversion was achieved when 3.01 M of 1,3‐BD concentration was treated in a toluene/cyclohexane mixture (7/3 [w/w]). The Co/Nd‐BR exhibited no gel formation with high mechanical performance, which was equivalent to commercial BR produced from a Nd‐based catalyst system. POLYM. ENG. SCI., 55:14–21, 2015. © 2014 Society of Plastics Engineers

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“…[17] In addition, the reported activation sequence of the Cp* 2 Gd + fragment by triisobutylaluminum (TIBA) suggests that polymer chains may be initiated by aluminum-bound isobutyl groups.Finally,the carbazole substituent in 1c is UV/ Vis-active and fluorescent, and will result in UV/Vis-active polymers,ifincorporated. [17] In addition, the reported activation sequence of the Cp* 2 Gd + fragment by triisobutylaluminum (TIBA) suggests that polymer chains may be initiated by aluminum-bound isobutyl groups.Finally,the carbazole substituent in 1c is UV/ Vis-active and fluorescent, and will result in UV/Vis-active polymers,ifincorporated.…”

Section: Resultsmentioning

confidence: 99%

Coordinative Chain Transfer Polymerization of Butadiene with Functionalized Aluminum Reagents

2019

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Functionalized aluminum alkyls enable effective coordinative chain transfer polymerization with selective chain initiation by the functionalized alkyl. (ω‐Aminoalkyl)diisobutylaluminum reagents (12 examples studied) obtained by hydroalumination of α‐amino‐ω‐enes with diisobutylaluminum hydride promote the stereoselective catalytic chain growth of butadiene on aluminum in the presence of Nd(versatate)3, Cp*2Nd(allyl), or Cp*2Gd(allyl) precatalysts and [PhNMe2H+]/[B(C6F5)4 −]. Carbazolyl‐ and indolylaluminum reagents result in efficient molecular weight control and chain initiation by the aminoalkyl rather than the isobutyl substituent bound to aluminum. As confirmed for (3‐(9H‐carbazol‐9‐yl)propyl)‐initiated polybutadiene (PBD), for example, by deuterium quenching studies, polymer chain transfer by β‐hydride transfer is negligible in comparison to back‐transfer to aluminum.

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Ultimately Specific 1,4‐cis Polymerization of 1,3‐Butadiene with a Novel Gadolinium Catalyst

Cited by 112 publications

References 15 publications

Cationic Alkyl Complexes of the Rare‐Earth Metals: Synthesis, Structure, and Reactivity

Cationic Alkyl Complexes of the Rare‐Earth Metals: Synthesis, Structure, and Reactivity

1,3‐butadiene polymerization using Co/Nd‐based Ziegler/Natta catalyst: Microstructures and properties of butadiene rubber

Coordinative Chain Transfer Polymerization of Butadiene with Functionalized Aluminum Reagents

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