461003-89-4Relevant academic research and scientific papers
Orientational control of guest molecules in an organic intercalation system by host polymer tacticity
Oshita, Shinya,Matsumoto, Akikazu
, p. 2139 - 2146 (2006)
Four kinds of stereoregular poly(muconic acid)s, which are synthesized by topochemical polymerization and subsequent solid-state hydrolysis, are used as the organic host materials for intercalation. We describe the reaction behavior and layered structure
Polymer crystal engineering for control of stereochemical structure of polymers: Stereospecific monomer synthesis and stereospecific solid-state polymerization
Matsumoto, Akikazu,Tanaka, Toshihiro
, p. 215 - 222 (2007/10/03)
We have successfully synthesized diisotactic and disyndiotactic polymers of (Z,Z)- and (E,E)-muconates with various benzyl ester groups. Muconic acid was conveniently converted into its corresponding ester derivatives without EZ isomerization when reacted with benzyl bromides in the presence of potassium carbonate in hexamethylphosphoramide (HMPA) at room temperature. Several monomers undergo photopolymerization in the crystalline state to give stereoregular polymers according to the monomer configuration and the ester substituents. X-ray single crystal structure analysis of the monomer and polymer crystals has revealed the process of the topochemical polymerization. In the monomer crystals with 4-alkoxybenzyl groups as the ester substituents, a columnar structure is formed by the alternate stacking of monomer molecules with the aid of weak hydrogen bonds such as CH/π and CH/O intermodular interactions. The alternate stacking is appropriate for syndiotactic polymerization, being different from the crystal structures of many other ester monomers which provide a diisotactic polymer due to the translational monomer stacking in a column, as is seen in the crystals of the 4-chloro-, 4-bromo-, and 4-nitro-substituted benzyl esters. Weak and flexible intermolecular interactions provide o variety of crystal structures and different type of molecular stacking leading to the different tacticity of the polymers.
First disyndiotactic polymer from a 1,4-disubstituted butadiene by alternate molecular stacking in the crystalline state
Tanaka, Toshihiro,Matsumoto, Akikazu
, p. 9676 - 9677 (2007/10/03)
We report the first synthesis of a disyndiotactic polymer through topochemical polymerization using di(4-methoxybenzyl)muconate as the 1,3-diene dicarboxylate monomer. It provides a tritactic polymer under photoirradiation in the crystalline state, as a r
