Syndiospecific styrene polymerization by (tert-BuC5H4)TiCl2(O-2,6- Pr2C6H3) – borate catalyst system

Effect of Cyclopentadienyl and Anionic Ancillary Ligand in Syndiospecific Styrene Polymerization Catalyzed by Nonbridged Half-Titanocenes Containing Aryloxo, Amide, and Anilide Ligands: Cocatalyst Systems

“…22 As summarized in Table 7, not only the choice of both borate and alkylaluminum compounds but also the optimization of molar ratios of the catalyst component are key for an efficient syndiospecific polymerization. This is because that Ph 3 CB(C 6 F 5 ) 4 explosively produces atactic polymer (APS) probably in a cationic manner (run 9), and [PhMe 2 NH]B(C 6 F 5 ) 4 and alkylaluminum compounds also afforded APS under similar polymerization conditions (runs 8, 10, 11).…”

“…4a,b In this paper, we thus wish to introduce our results concerning the effect of both the cyclopentadienyl and the anionic donor ligands in syndiospecific styrene polymerization with a series of nonbridged half-titanocenes of the type Cp′TiCl 2 (L) [L ) O-2,6-i Pr 2 C 6 H 3 , Cp′ ) Cp (1), 1,3-Me 2 C 5 H 3 (2), 1,2,4-Me 3 C 5 H 2 (3), C 5 Me 5 (Cp*, 4); Cp′ ) Cp*, L ) OPh (5), O-4-MeC 6 H 4 (6), O-2,6-Me 2 C 6 H 3 (7), O-2,6-t Bu 2 C 6 H 3 (8); Cp′ ) 1,3-Me 2 C 5 H 3 , L ) NMeCy (9), N(2,6-Me 2 C 6 H 3 )(SiMe 3 ) (10), Chart 1] in the presence of methylaluminoxane (MAO). [18][19][20][21] Since we recently communicated that (tert-BuC 5 H 4 )TiMe 2 (OAr) (11, OAr ) O-2,6-i Pr 2 C 6 H 3 ) was effective for syndiospecific polymerization of styrene in the presence of a mixture of Al(n-C 8 H 17 )/Al i Bu 3 and Ph 3 CB(C 6 F 5 ) 4 , 22 we explored the role of both the cyclopentadienyl and the aryloxide ligands in this catalysis. Table 1 summarizes the results for styrene polymerization with a series of Cp′TiCl 2 (O-2,6-i Pr 2 C 6 H 3 ) (1-4) and Cp′TiCl 3 [Cp′ ) Cp (1′), 1,3-Me 2 C 5 H 3 (2′), 1,2,4-Me 3 C 5 H 2 (3′), C 5 Me 5 (4′)] complexes in the presence of MAO at various temperatures.…”

Syndiospecific styrene polymerization with CpTiCl3/MAO: Effects of the order of reactant addition on polymerization and polymer properties

“…A recent review covers syndiospecific styrene polymerization, especially the catalytic systems 3. Studies in this field have led to the conclusion that half‐sandwich titanium chloride, fluoride, or alkyoxide compounds containing η 5 ‐C 5 H 5 , η 5 ‐C 5 Me 5 , η 5 ‐C 5 Me 4 H, or η 5 ‐C 9 H 7 ligands are among the favored precursors 4–13. Kinetic studies of syndiospecific styrene polymerization with various metallocene catalyst systems have been reported by several research groups 14–21.…”

Synthesis of Ultrahigh Molecular Weight Polymers Containing Reactive Functionality with Low PDIs by Polymerizations of Long-Chain α-Olefins in the Presence of Their Nonconjugated Dienes by Cp*TiMe2(O-2,6-iPr2C6H3)–Borate Catalyst

“…On the basis of our previous reports for polymerizations of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) [22], and of 1,7-octadiene [38] ; the ratios were used on the basis of the homo polymerization results [22]. As reported previously [22,29,[47][48][49], use of Al(n-C 8 H 17 ) 3 , weak reagent for alkylation, and/or chain transfer was effective to proceed without catalyst deactivation, probably not only due to a role as a scavenger, but also due to the fact that the Al alkyl would contribute to the stabilization of the catalytically active species by preventing the decomposition from further reaction with borate [50][51][52]. The results in the DC/DCD copolymerization are summarized in Table 1.…”