New Macromolecular Architectures for Permselective Membranes—Gas Permselective Membranes from Dendrimers and Enantioselectively Permeable Membranes from One-handed Helical Polymers—

Abstract

ABSTRACT:Chemistry of macromolecular architecture is one of the fastest growing branches of polymer chemistry. The present review describes macromolecular architectures for permselective membranes relating their structures and permselectivity, and is focused on dendrimers for gas permselective membranes and one-handed helical polymer membranes for enantioselectively permeable membranes (optical resolution). The first part of this review described the three kinds of permselective membranes prepared from pure polydendrons or dendronized polymers having self-membrane-forming ability by us, and from another polymer and dendrimers or hyperbranched polymers as a crosslinker, and from another supporting membrane and dendrimers as a modifier. The membranes from polydendrons showed better oxygen permselectivities than those of conventional polymer membranes. In the second part, three kinds of enantioselectively permeable membranes reported by many researchers, i.e., chiral carriers-containing composite membranes, membranes based on chiral HPLC stationary phase polymers, and chiral molecular imprinting membranes, are reviewed briefly. In particular, the detail of our macromolecular designs of one-handed helical poly(substituted acetylene)s as materials for enantioselectively permeable membranes is discussed as the fourth category. When the content of the chiral groups was higher, the permselectivity was enhanced. The one-handed helical backbones were found to be effective for enantioselective permeation. It was also shown that the disadvantage of this method, i.e., low permeation rate was improved by using thinner membranes. In addition, enantioselectively permeable membranes are classified from the view point of their permeation mechanisms.

Helix Formation of Poly(phenylacetylene)s Bearing Azide Groups through Click Polymer Reaction with Optically Active Acetylenes

“…The stereoregularities of all the polymers were rich in cis-transoid judging from 1 H NMR spectroscopy ( Figure S1). 17,[20][21][22][23][24][25][26][27] Figure 1 shows the CD and absorption spectra of poly-3 and poly-4 in dimethyl sulfoxide (DMSO) containing a small amount of acetic acid, which was used due to the solubility problem of these polymers in DMSO. Poly-3 and poly-4 showed a difference in their CD and absorption spectral patterns because of the methylene linker of poly-4 that likely reduced the -conjugated length of the polymer.…”

“…Here we report an alternative method for preparing optically active helical poly(phenylacetylene)s [16][17][18][19][20][21][22][23] based on the helicity induction [16][17][18][24][25][26][27] on optically inactive poly(phenylacetylene)s bearing azide pendant groups (poly-1 and poly-2) by the click polymer reaction using chiral acetylenes (Scheme 1). We anticipated that a preferred-handed helical structure could be induced in the optically inactive poly-1 and poly-2 through the covalent bonding of optically active substituents after the click polymer reaction, which could be easily detected by circular dichroism (CD) spectroscopy, and that this approach might be applicable for developing a facile system to sense the chirality of chiral acetylenes.…”

Synthesis of Multifunctional Poly(calix[4]resorcinarene)

“…7 With further functionalization, polymer 3 is expected to show significant material potential as a network polymer, zeolite-like porous material, ion-exchange resin, nano-composite, etc. [9][10][11] This work was partially supported by the Industrial Technology R & D Grant (04A23030) from NEDO of Japan. …”

Chiral amplification in double-stranded helical polymers through chiral and achiral amidinium–carboxylate salt bridges

“…[1][2][3] Although a large number of singlestranded helical polymers and oligomers have been reported, [2][3][4][5][6][7][8][9][10][11][12] examples of double-stranded helical polymers and oligomers remain relatively scarce. 2,3,8,9,[13][14][15][16][17][18][19][20][21][22] We have recently reported on the rational design and synthesis of a series of complementary double-stranded helical oligomers [23][24][25][26][27][28] with an optical activity that consists of a crescent-shaped m-terphenyl-based backbone containing amidine and carboxylic acid groups.…”