Syndiospecific living polymerization of 4-methylstyrene with (trimethyl)pentamethylcyclopentadienyltitanium/tris(pentafluorophenyl)borane/trioctylaluminium catalytic system

Abstract

SUMMARY: The polymerization of 4-methylstyrene with the (trimethyl)pentamethylcyclopentadienyltitanium (Cp*TiMe 3 )/tris(pentafluorophenyl)borane (B(C 6 F 5 ) 3 )/trioctylaluminium (AlOct 3 ) catalytic system at -20 8C was carried out. The number-average molecular weight (M -n ) of the polymers increased linearly with increasing monomer conversion. The propagating chain ends were successfully reacted with tert-butyl isocyanate, and the M -n of the polymer determined by 1 H NMR was in good agreement with the M -n determined by GPC measurement. It is concluded that this catalytic system promoted the syndiospecific living polymerization of 4-methylstyrene.

Highly Sensitive NH3 Detection Based on Organic Field-Effect Transistors with Tris(pentafluorophenyl)borane as Receptor

“…15 TPFB is frequently used as a strongly Lewis acidic co-catalyst in numerous reactions, such as dehydration, 16 Friedel-Crafts reactions, 17 ring-opening reactions, 18 and syndiospecific living polymerization. 19 Here, TPFB was chosen as the NH3 receptor additive to the OFET semiconductors due to the strong interaction between boron atoms and nitrogen atoms 20 and the known vacuum sublimability of TPFB. Furthermore, the hydrogen bonds formed between hydrogen and fluorine atoms also play a role in the complexation process, with the NH3 molecule tightly bound to TPFB through all its four atoms (Scheme 1).…”

Novel Calcium Half-Sandwich Complexes for the Living and Stereoselective Polymerization of Styrene

“…Under certain conditions, the polymerization of para-methylstyrene by titanium half-sandwich complexes shows living features, however, the system was not suitable for the living syndiotactic polymerization of styrene. [10] Our approach to enable a living and a syndiospecific polymerization of styrene is based on ªcross-breedingº the catalysts (RLi) used for classical anionic styrene polymerization and that for coordination polymerization (Scheme 1). A proposed catalytic species for coordination polymerization Scheme 1. is a cationic Ti III complex with a cyclopentadienyl spectator ligand and a growing chain.…”

Regulatory updates

“…In this study, we thoroughly report the living natures of the 4MS polymerizations by Cp*TiMe 3 /B(C 6 F 5 ) 3 /AlOct 3 catalytic system, as an extension of our previous research 54. We also report the syndiospecific living polymerization of styrene and the living random copolymerization of 4MS and styrene with this catalytic system.…”

“…The objective of this work is to establish the methodology for syndiospecific living polymerization of styrene derivatives by focusing on the role of the third component of the catalytic system on the polymerization behavior. We reported that a half‐metallocene type catalytic system composed of Cp*TiMe 3 , B(C 6 F 5 ) 3 , and trioctylaluminum (AlOct 3 ) initiated a living polymerization of 4‐methylstyrene (4MS) at −20 °C to yield syndiotactic poly(4‐methylstyrene) [poly(4MS)] with narrow molecular weight distribution ( M w / M n = 1.3–1.4) at a relatively low monomer conversion of below 20% 54. We also reported the syndiospecific living polymerization of 4‐( tert ‐butyldimethylsilyloxy)styrene (TBDMSS),55 the sequential block copolymerizations of TBDMSS and 4MS,56 and the syntheses of both SPS‐based block copolymers and SPS‐based block graft copolymer by using the living polymerization system 57…”