title: Air-stable (phenylbuta-1,3-diynyl)palladium(II) complexes: highly active initiators for living polymerization of isocyanides.
abstract: A family of air-stable (phenylbuta-1,3-diynyl)palladium(II) complexes were designed and prepared in a facile synthetic procedure. Their structures were characterized by (1)H and (13)C NMR, MS, and X-ray analysis. These Pd complexes were revealed to efficiently initiate the polymerization of phenyl isocyanides in a living/controlled chain growth manner, which led to the formation of poly(phenyl isocyanide)s with controlled molecular weights and narrow molecular weight distributions. (13)C NMR analysis indicated the isolated poly(phenyl isocyanide) was of high stereoregularity. The Pd unit at the end of the polymer chain could undergo further copolymerization with phenyl isocyanide monomers to give block copolymers. It was also found that incorporation of an electron-donating group on the phenyl group of the Pd complex could improve the catalytic activities. Furthermore, these Pd complexes were tolerant to most organic solvents and applicable to a wide range of isocyanide monomers including alkyl and phenyl isocyanides and even phenyl isocyanide with bulky substituents at the ortho position and diisocyanide monomers. Therefore, this polymerization system is versatile in the preparation of well-defined polyisocyanides with controlled sequence. Bi- and trifunctional Pd complexes with two and three Pd units incorporated onto the same phenyl ring were designed and synthesized. They were also able to initiate the living polymerization of phenyl isocyanide to afford telechelic linear and star-shaped polyisocyanides with controlled molecular weights and narrow molecular weight distributions.
authors.affiliation: Department of Polymer Science and Engineering, School of Chemical Engineering, Hefei University of Technology and Anhui Key Laboratory of Advanced Functional Materials and Devices , Hefei 230009, China.
authors.forename: Ya-Xin
authors.initials: YX
authors.lastname: Xue
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Zhu
authors.forename: Long-Mei
authors.initials: LM
authors.lastname: Gao
authors.forename: Xiao-Yue
authors.initials: XY
authors.lastname: He
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Wu-Yi
authors.initials: WY
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Ding
authors.forename: Hongping
authors.initials: H
authors.lastname: Zhou
authors.forename: Zong-Quan
authors.initials: ZQ
authors.lastname: Wu
mesh_terms: D000388:Air; D003486:Cyanides / Q000737:chemistry*; D004355:Drug Stability; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D058105:Polymerization
chemical_list: D003486:Cyanides; D009942:Organometallic Compounds; D010165:Palladium