Pseudo-Halide and Nitrate Derivatives of Grubbs and Grubbs-Hoveyda Initiators: Some Structural Features Related to the Alternating Ring-Opening Metathesis Copolymerization of Norborn-2-ene with Cyclic Olefins
Pseudo-Halide and Nitrate Derivatives of Grubbs and Grubbs-Hoveyda Initiators: Some Structural Features Related to the Alternating Ring-Opening Metathesis Copolymerization of Norborn-2-ene with Cyclic Olefins
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DOI：
10.1021/ma200995m
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发表时间：
2011-06-14
期刊：
影响因子：
5.5
通讯作者：
Kumar, P. Santhosh
中科院分区：
文献类型：
--
作者：
Buchmeiser, Michael R.;Ahmad, Irshad;Kumar, P. Santhosh
一系列新型的Ru-亚烷基引发剂，其中两个氯配体都被假卤化物或硝酸盐取代，即[Ru(NCO)(2)(iMesh(2))(C5H5N)(CHC6H5)](1b)，[Ru(CF3SO3)(2)(iMesh(2))(C5H5N)(CHC6H5)](1c)，[Ru(NCO)(CF3SO3)(iMesh(2))(C5H5N)(CHC6H5)](1D)，[Ru(CF3SO3)(CF3CO2)(iMesh(2).)(C5H5N)(CHC6H5)](1e)，[Ru(NCS)(2)(iMesh(2))(C5H5N)(CHC6H5)](1f)，[Ru(NO3)(2)(iMesh(2))(CH-2-(2-PRO)-C6H4)](2d)，和[Ru((CF2)(3)(CO2)(2))(iMesh(2))(CH-2-(2-Pro)(C6H4)](2f)(iMesh(2)=1，3-二亚甲基咪唑啉-2-亚甲基)。新型引发剂和通式[RuX2(L)(N)(NHc)(CHPh)]和[RuX2(Nhc)(CH-2-(2-PRO)-C6H4)](X=Cl，C6F5COO；nhc=iMesh(2)，1，3-二偏甲基嘧啶-2-亚甲基，1，3-二甲基二氮卓-2-亚甲基，1-mesityl-3-(2-phenylethyl)imidazolin-2-ylidene，1-甲苯基-3-金刚烷基二唑啉-2-亚甲基；L=PCy3，吡啶，n=1，2)分别与环戊烯(CPE)和顺式环辛烯(COE)交替共聚。合成了交替共聚物，即聚(NBE-ALT-CPE)(N)和聚(NBE-ALT-COE)(N)，其中交替二联体的含量分别为55%和40%。此外，引发剂4b是环戊烯均聚反应的高效引发剂，可以合成高相对分子质量的聚(CPE)。提出了拟卤素配体的性质对NBE与CPE或COE交替共聚程度的一些基本影响。最后讨论了N-杂环卡宾的环大小对最终聚合物中双键构型的影响。
A series of novel Ru-alkylidene-based initiators, in which both chloride ligands were replaced by pseudo-halides or by nitrate, i.e., [Ru(NCO)(2)(IMesH(2))(C5H5N)(CHC6H5)] (1b), [Ru(CF3SO3)(2)(IMesH(2))(C5H5N)(CHC6H5)] (1c), [Ru(NCO) (CF3SO3)(IMesH(2))(C5H5N)(CHC6H5)] (1d), [Ru(CF3SO3) (CF3CO2) (IMesH(2).)(C5H5N) (CHC6H5)] (1e), [Ru(NCS)(2) (IMesH(2))(C5H5N)(CHC6H5)] (1f), [Ru(NO3)(2)(IMesH(2)) (CH-2-(2-PrO)-C6H4)] (2d), and [Ru( (CF2)(3) (CO2)(2)) (IMesH(2)) (CH-2-(2-PrO) (C6H4)] (2f) (IMesH(2) = 1,3-dimesitylimidazolin-2-ylidene), have been prepared. The novel initiators and those of the general formula [RuX2(L)(n)(NHC)(CHPh)] and [RuX2(NHC)(CH-2-(2-PrO)-C6H4)] (X = Cl, C6F5COO; NHC = IMesH(2), 1,3-dimesitylpyrimidin-2-ylidene, 1,3-dimesityldiazepin-2-ylidene, 1-mesityl-3-(2-phenylethyl)imidazolin-2-ylidene, 1-mesityl-3-adamantylimidiazolin-2-ylidene; L = PCy3, pyridine, n = 1, 2) were investigated for their propensity to copolymerize NBE with cyclopentene (CPE) and cis-cyclooctene (COE), respectively, in an alternating way. Alternating copolymers, that is, poly(NBE-alt-CPE)(n) and poly(NBE-alt-COE)(n) containing up to 55 and 40% alternating diads, respectively, were obtained. Moreover, initiator 4b turned out to be a highly efficient initiator for the homopolymerization of cyclopentene (CPE), allowing for the synthesis of high-molecular-weight poly(CPE). Some fundamental effects cif the nature of the pseudo-halide ligand on the extent of alternating copolymerization of NBE with CPE or COE are presented. Finally, the effects of the ring size of the N-heterocyclic carbene on the configuration of the double bonds in the final polymer are addressed..