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Scandium-catalyzed stereoselective block and alternating copolymerization of diphenylphosphinostyrenes and isoprene
Polymer Chemistry ( IF 4.1 ) Pub Date : 2022-05-19 , DOI: 10.1039/d2py00290f Tingting Fu 1 , Lei Jiang 1 , Hanyang Sun 1 , Zhaomin Hou 1, 2, 3 , Fang Guo 1
Polymer Chemistry ( IF 4.1 ) Pub Date : 2022-05-19 , DOI: 10.1039/d2py00290f Tingting Fu 1 , Lei Jiang 1 , Hanyang Sun 1 , Zhaomin Hou 1, 2, 3 , Fang Guo 1
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The coordination copolymerization of polar diphenylphosphinostyrenes (StPPh2) and isoprene (IP) by a half-sandwich scandium catalyst (C5Me4SiMe3)Sc(CH2C6H4NMe2-o)2 afforded a new series of phosphine-functionalized alternating and block isoprene–styrene copolymers. In the copolymerization of p-StPPh2 with IP, the incorporation of p-StPPh2 into the polymer chains started after IP was almost completely consumed, yielding the p-StPPh2–IP diblock copolymers containing a syndiotactic-rich poly(p-StPPh2) block and a poly(IP) block containing 1,4- and 3,4-structures, probably because the coordination of IP to the catalyst is favored over that of p-StPPh2. In the copolymerization of o-StPPh2 with IP, the o-StPPh2–IP alternating copolymer was exclusively formed with the coexistence of the two monomers, because the successive insertion of o-StPPh2 was difficult due to steric hindrance caused by the phosphine/styrene chelation to the catalyst metal center. When an excess amount of IP was used in the copolymerization of o-StPPh2 and IP, the formation of a poly(IP) block was achieved after o-StPPh2 was consumed in the alternating copolymerization, thus affording block copolymers containing an o-StPPh2–IP alternating block and a poly(IP) block. Moreover, the incorporation of IP in the alternating copolymerization with o-StPPh2 took place in a regio- and stereospecific cis-1,4-fashion (95%), suggesting that the coordination (chelation) of o-StPPh2 to the catalyst could influence the regio- and stereoselectivity of IP polymerization.
中文翻译：
钪催化立体选择性嵌段和二苯基膦苯乙烯与异戊二烯的交替共聚
半夹心钪催化剂 (C 5 Me 4 SiMe 3 )Sc(CH 2 C 6 H 4 NMe 2 - o ) 2将极性二苯基膦基苯乙烯 (StPPh 2 ) 和异戊二烯 (IP) 配位共聚得到一系列新的膦-官能化交替和嵌段异戊二烯-苯乙烯共聚物。在p -StPPh 2与 IP的共聚中，在 IP 几乎完全消耗后，p -StPPh 2开始进入聚合物链，产生p -StPPh 2–IP 二嵌段共聚物含有一个富含间规立构的聚 ( p -StPPh 2 ) 嵌段和一个含有 1,4- 和 3,4- 结构的聚 (IP) 嵌段，可能是因为 IP 与催化剂的配位比p -StPPh 2。在o -StPPh 2与IP的共聚过程中，o - StPPh 2 -IP交替共聚物仅由两种单体共存形成，因为o -StPPh 2的连续插入由于膦/苯乙烯螯合催化剂金属中心引起的空间位阻，很难。当在o -StPPh 2和IP的共聚中使用过量的IP时，在交替共聚中消耗o -StPPh 2后形成聚(IP)嵌段，从而得到含有o-的嵌段共聚物。 StPPh 2 –IP 交替嵌段和聚 (IP) 嵌段。此外，IP 在与o -StPPh 2的交替共聚中以区域和立体特异性顺式-1,4-方式 (95%) 发生，表明o的配位（螯合）-StPPh 2对催化剂的影响会影响IP聚合的区域选择性和立体选择性。
更新日期：2022-05-19
中文翻译：
钪催化立体选择性嵌段和二苯基膦苯乙烯与异戊二烯的交替共聚
半夹心钪催化剂 (C 5 Me 4 SiMe 3 )Sc(CH 2 C 6 H 4 NMe 2 - o ) 2将极性二苯基膦基苯乙烯 (StPPh 2 ) 和异戊二烯 (IP) 配位共聚得到一系列新的膦-官能化交替和嵌段异戊二烯-苯乙烯共聚物。在p -StPPh 2与 IP的共聚中，在 IP 几乎完全消耗后，p -StPPh 2开始进入聚合物链，产生p -StPPh 2–IP 二嵌段共聚物含有一个富含间规立构的聚 ( p -StPPh 2 ) 嵌段和一个含有 1,4- 和 3,4- 结构的聚 (IP) 嵌段，可能是因为 IP 与催化剂的配位比p -StPPh 2。在o -StPPh 2与IP的共聚过程中，o - StPPh 2 -IP交替共聚物仅由两种单体共存形成，因为o -StPPh 2的连续插入由于膦/苯乙烯螯合催化剂金属中心引起的空间位阻，很难。当在o -StPPh 2和IP的共聚中使用过量的IP时，在交替共聚中消耗o -StPPh 2后形成聚(IP)嵌段，从而得到含有o-的嵌段共聚物。 StPPh 2 –IP 交替嵌段和聚 (IP) 嵌段。此外，IP 在与o -StPPh 2的交替共聚中以区域和立体特异性顺式-1,4-方式 (95%) 发生，表明o的配位（螯合）-StPPh 2对催化剂的影响会影响IP聚合的区域选择性和立体选择性。
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