One-dimensional inclusion polymerization

A chiral host could readily be available from a naturally occurring compound. The use of steroidal acid, deoxycholic acid (Fig. 3d), yielded coinprehensive polymers, particularly, optically active polymers from pro-chiral monomers. Many derivatives of deoxy cholic acid have the corresponding characteristic inclusion abilities. For example, use of apocholic acid (Fig. 3e), cholic acid (Fig. 3f), and chenodeoxycholic acid (Fig. 3g) enabled us to perform one-dimensional inclusion polymerization of various diene and vinyl monomers. 

Fig. 3 Organic hosts used for one-dimensional inclusion polymerization (a) urea (b) thiourea (c) perhydrotriphenylene (d) deoxycholic acid (e) apocholic acid (f) cholic acid (g) chenodeoxycholic acid (h) m5 (6>-phenylenedioxy)cyclotriphosphazene and (i) n5(2,3-naphthalenedioxy)cyclotriphosphazene.

Fig. 4 Various monomers used for one-dimensional inclusion polymerization...

There are many possible schemes for addition reactions of diene monomers from electronical and steric viewpoints. Because the monomer molecules arrange along the direction of the channels, a,co-addition may selectively take place in one-dimensional inclusion polymerization. Therefore, conjugated polyenes, such as dienes and trienes, may selectively polymerize by 1,4- and 1,6-addi-tion, respectively. 1,3-Butadiene polymerized via 1,4-addition exclusively in the chaimels of urea and perhydrotriphenylene. while the same monomer polymerized via both 1,2- and 1,4-additions in the channels of deoxycholic acid and apocholic acid. Moreover, we have to evaluate head-to-tail or head-to-head (tail-to-tail) additions in the case of dissymmetric conjugated diene monomers such as isoprene and 1.3-pentadiene. 

Harata et al. [27] reported the crystal structures of four 6-monosubstituted -CDSy 6-O-(l-propyl)amino-j0-CD, 6-O-[(i )-l-cyclohexylethyl]amino-)0-CD, 6-O-[(i )-l-phenylethyl]amino-j0-CD, and 6-0-[(li, 2S)-2-hydroxyindan-l-yl]amino-j0-CD. They discussed the relationship between crystal packing and the inclusion of the substituent group (Fig. 10). In each crystal, the substituent groups were inserted into the adjacent p CD cavity from the secondary hydroxyl side. This host-guest type self-association through inter-molecular inclusion generates a one-dimensional polymeric chain. 6-0-(l-Propyl)amino- -CD and 6-O-[(i )-l-cyclohexylethyl]amino-j0-CD form... 

Inclusion polymerization is a unique one-dimensional polymerization which proceeds in a canal (channel) of inclusion compounds, and an excellent way for giving stereoregular polymers as well as composite materials at molecular level [l,2]. Such materials have a potential possibility to show some characteristic electrical, optical and magnetic properties in the inclusion state due to their one-dimensional structure. 

A second motif encountered in tetrapyridylporphyiin systems is typified by inclusion compounds with wet methanol and water that produce three-dimensional coordination polymers. Ttv/ni-pyridyl substituents on a Zn(TPyP) were ob.served to axially ligate the metal centers of adjacent porphyrin moieties generating a polymeric chain in one dimension. Cross-linking in a second dimension occurs when the original porphyrin molecule is coordinated by two pyridyl moieties from two additional porphyrin molecules... 

In general, one can insert one or more types of fillers in polymeric matrices aiming for a unique combination of properties, and these fillers may present diflerent chemical and physical properties, and also broad dimensional range these fillers can present no dimension (i.e. nanoparticles), be unidimensional (nanotubes), bidimensional (coatings and lamers) or tridimensional (tridimensional nets or macroparticles). " The inclusion of these fillers in vulcanized NR, generating composite or nanocomposite materials, gives to these materials different structural, chemical, physical, thermal, electric, electrochemical, optical and magnetic properties. ... 

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