Steric Hindrance Drives the Boron‐Initiated Polymerization of Dienyltriphenylarsonium Ylides to Photoluminescent C5‐Polymers
作者:Xin Wang、Nikos Hadjichristidis
DOI:10.1002/anie.202109190
日期:2021.10.4
A series of alkyl-subsituted dienyltriphenylarsonium ylides were synthesized and used as monomers in borane-initiated polymerization to obtain practically pure C5-polymers (main-chain grows by five carbon atoms at a time). The impact of triethylborane (Et3B), tributylborane (Bu3B), tri-sec-butylborane (s-Bu3B), and triphenylborane (Ph3B) initiators on C5 polymerization was studied. Based on NMR and
合成了一系列烷基取代的二烯基三苯基胂叶立德,并将其用作硼烷引发聚合的单体,以获得几乎纯的C5聚合物(主链一次增长五个碳原子)。研究了三乙基硼烷(Et 3 B)、三丁基硼烷(Bu 3 B)、三仲丁基硼烷( s -Bu 3 B)和三苯基硼烷(Ph 3 B)引发剂对C5聚合的影响。基于 NMR 和 SEC 结果,我们表明所有合成的聚合物都具有具有独特不饱和主链的 C5 单元,其中两个共轭双键被一个亚甲基分隔。合成的C5聚合物具有可预测的分子量和窄的分子量分布( M n,NMR =2.8 −11.9 kg mol −1 , Ð =1.04–1.24)。研究发现,增加单体和引发剂的空间位阻可以促进更多C5重复单元的形成,从而驱动聚合反应形成几乎纯的C5聚合物(高达95.8%)。通过11 B NMR 研究了聚合机理,并通过 DFT 计算证实了聚合机理。合成的C5聚合物是无定形的,通过调节单体的取代基可调节玻璃化转变温度,范围为+30