Seminar

Seminar

Living Supramolecular Polymerization

  • POSTED DATE : 2016-10-04
  • WRITER : 관리자
  • HIT : 3517
  • DATE : 2016-10-06
  • PLACE : 화학관 330226호

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제  목 : Living Supramolecular Polymerization


연  사 : Dr Kazunori Sugiyasu(NIMS)


일  시 : 2016년 10월 6일(목) 오후 4시 30분


장  소 : 화학관 세미나실 (330226호실)

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Living Supramolecular Polymerization


 


Kazunori Sugiyasu


Molecular Design & Function Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan


E-mail: SUGIYASU.Kazunori@nims.go.jp


 


   Supramolecular polymers are a new type of polymer in which monomeric units are brought together by reversible and highly directional non-covalent bonds, such as hydrogen bonding, coordination bonding, and p-p stacking. Therefore, supramolecular polymers are endowed with intriguing functionalities and properties that originate from the dynamic behavior of the non-covalent bonds. However, the “dynamic” reversible polymerization process in turn implies that controlling the length of supramolecular polymers is entropically unlikely. As such, in contrast to conventional polymer chemistry, an important challenge in realizing living polymerization technique has still remained in the supramolecular polymer chemistry1.


In this presentation, I would like to show the first example of living supramolecular polymerization reported by us recently2. Our supramolecular polymerization was very unique in that the polymerization pathway was coupled with a competing aggregation pathway3. This pathway complexity dictated the spontaneous supramolecular polymerization to be kinetically controlled, and the addition of “seeds” of the supramolecular polymer initiated the supramolecular polymerization. We have investigated this polymerization process in a similar way to analyze the living polymerization: (1) the polymerization kinetics was the first order to the concentration of the seeds, (2) polymerization can be repeated many times, and (3) polydispersity indices (PDI) of the obtained polymers were around 1.1. All these results demonstrated that we succeeded for the first time in realizing living supramolecular polymerization.


 


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Scheme 1. Pathway complexity of supramolecular polymerization2.


 


 


References


  1. (a) de Greef, T. F. A.; Smulders, M. M. J.; Wolffs, M. ; Schenning, A. P. H. J.; Sijbesma, R. P.; Meijer, E. W. Chem. Rev. 2009, 109, 5687; (b) van der Zwaag, D.; de Greef, T. F. A.; Meijer, E. W. Angew. Chem. Int. Ed. 2015, 54, 8334; (c) Ogi, S.; Stepanenko, V.; Sugiyasu, K.; Takeuchi, M.; Würthner, F. J. Am. Chem. Soc. 2015,137, 3300; (d) Kang, J.; Miyajima, D.; Mori, T.; Inoue, Y.; Aida, T. Science2015, 347, 646.

  2. Ogi, S.; Sugiyasu, K.; Manna, S.; Samitsu, S.; Takeuchi, M. Nat. Chem. 2014, 6, 188.

  3. Ogi, S.; Fukui, T.; Melinda, L. J.; Takeuchi, M.; Sugiyasu, K. Angew. Chem. Int. Ed. 2014, 53, 14363.