Formula: C19H18BrPIn 2020 ,《Syndioselective 3,4-Polymerization of 1-Phenyl-1,3-Butadiene by Rare-Earth Metal Catalysts》 was published in ACS Catalysis. The article was written by Jiang, Yang; Kang, Xiaohui; Zhang, Zhen; Li, Shihui; Cui, Dongmei. The article contains the following contents:
Coordination polymerization of 1-phenyl-1,3-butadiene (1PB) was carried out by diiminophosphinato lutetium complexes 1 and 2, pyridyl-methylene-fluorenyl complexes 3 (Sc 3a; Lu 3b; Y 3c) and 4 (Sc 4a; Lu 4b; Y 4c), β-diiminato yttrium complex 5, bis(imino)aryl gadolinium complex 6, bis(phosphino)carbazolide yttrium complex 7 and bis(phosphinophenyl)amido complex 8. Complexes 1, 2, 3a,b and 4a,b, under the activation of [Ph3C][B(C6F5)4] and AliBu3, show high activities as well as higher than 96.6% 3,4-regio selectivities, of which 1 and 2 are non stereoselective to give atactic 3,4-poly(1PB), while 3a,b and 4a,b exhibit distinguished syndioselectivities (> 95.3% rrrr). However, 3c and 4c are inactive. In addition, complexes 5-7 are also completely inert although they are highly active and cis-1,4 selective for isoprene polymerization On contrary, the analogous cis-1,4 selective complex 8 exhibits syndio- (> 96.1% rrrr) and 3,4-regio (> 99%) selectivity. Hydrogenation of a syndiotactic 3,4-poly(1PB) affords a syndiotactic poly(4-phenyl-1-butene) elastomer with a Tg of 17°C. The cationic cyclization transfers a syndiotactic 3,4-poly(1PB) into a rigid cyclized polyolefin with a Tg as high as 327°C. DFT simulations are employed to illustrate the mechanisms for control of activity and stereo-selectivity from thermodn. and geometric viewpoints. The results came from multiple reactions, including the reaction of Methyltriphenylphosphonium bromide(cas: 1779-49-3Formula: C19H18BrP)
Methyltriphenylphosphonium bromide(cas: 1779-49-3) is a lipophilic molecule with a cation allowing for it to be used to deliver molecules to specific cell components. Also considered an antineoplastic agent.Formula: C19H18BrP
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary