Porphyrin-Based Supramolecular Alternating Block Copolymer

Wednesday, May 14, 2014: 09:00
Bonnet Creek Ballroom X, Lobby Level (Hilton Orlando Bonnet Creek)
T. Haino (Graduate School of Science, Hiroshima University)
S-shaped tetrakisporphyrin 1 forms supramolecular polymeric assemblies via a complementary affinity1,2 of its bisporphyrin units in solution.3 The self-association constant determined by applying the isodesmic model is more than 106 L mol–1, which suggests that a sizable polymer forms at millimolar concentrations at room temperature. Trinitrofluorenone (TNF) binds within the molecular clefts provided by the bisporphyrin units via a charge transfer interaction. Thus, bisTNF guest can connect the tetrakisporphyrin via host-guest interaction to form an alternating block copolymer. In this presentation, we will discuss the structure transition from the tetrakisporphyrin-based supramolecular homopolymer to an alternating AB type block copolymer through competitive ditopic guest complexation.

1) Haino, T. et al., Y. Tetrahedron Lett. 2005, 46, 257.

2) Haino, T. et al., Y. J. Org. Chem. 2006, 71, 2572.

3) Haino, T. et al., U. Proc. Natl. Acad. Sci. USA 2009, 106, 10477.