Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
J Am Chem Soc. 2013 Jun 19;135(24):8810-3. doi: 10.1021/ja4036175. Epub 2013 Jun 7.
Poly(2-isopropenyl-2-oxazoline) (PIPOx) and poly(2-vinylpyridine) (P2VP) have been efficiently synthesized using bis(cyclopentadienyl)methylytterbium (Cp2YbMe) as catalyst. The polymerizations of 2-isopropenyl-2-oxazoline (IPOx) and 2-vinylpyridine (2VP) follow a living group-transfer polymerization (GTP) mechanism, allowing a precise molecular-weight control of both polymers with very narrow molecular-weight distribution. The GTP of IPOx and 2VP occurs via N coordination at the rare earth metal center, which has rarely been reported previously. The relative coordination strength of different monomers at the ytterbium center is determined by copolymerization investigations to be in the order of DEVP > MMA > IPOx > 2VP. In combination with living cationic ring-opening polymerization, PIPOx is converted to molecular brushes with defined backbone and poly(2-oxazoline) side chains using the grafting-from method.
聚（2-异丙基-2-恶唑啉）（PIPOx）和聚（2-乙烯基吡啶）（P2VP）已成功使用双（环戊二烯基）甲基镱（Cp2YbMe）作为催化剂合成。2-异丙基-2-恶唑啉（IPOx）和 2-乙烯基吡啶（2VP）的聚合遵循活的基团转移聚合（GTP）机理，允许两种聚合物具有非常窄的分子量分布的精确分子量控制。GTP 的 IPOx 和 2VP 通过在稀土金属中心的 N 配位发生，这在以前很少有报道。通过共聚研究确定不同单体在镱中心的相对配位强度顺序为 DEVP > MMA > IPOx > 2VP。结合活的阳离子开环聚合，通过接枝法将 PIPOx 转化为具有定义的主链和聚（2-恶唑啉）侧链的分子刷。
