The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Jiro Kumaki - One of the best experts on this subject based on the ideXlab platform.

  • amplification of macromolecular helicity of dynamic helical poly phenylacetylene s bearing non racemic alanine pendants in Dilute Solution liquid crystal and two dimensional crystal
    Polymer Journal, 2012
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers composed of non-racemic phenylacetylenes bearing L- and D-alanine decyl esters as the side groups (poly(1Lm-co-1Dn), m>n) were prepared by the copolymerization of the corresponding L- and D-phenylacetylenes with different enantiomeric excesses using a rhodium catalyst; their chiral amplification of the helical conformation as an excess of one-handedness in a Dilute Solution, in a lyotropic liquid-crystalline (LC) state and in a two-dimensional (2D) crystal on substrate was investigated by measuring the circular dichroism spectra of the copolymers at different temperatures, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch) and high-reSolution atomic force microscopy images of the self-assembled 2D helix-bundle structures of the copolymer chains, respectively. We have observed a unique amplification of the helical-sense excess (majority rule effect) of dynamic helical, liquid-crystalline (LC) poly(phenylacetylene)s bearing non-racemic D- and L-alanine residues as the pendant groups in a Dilute Solution, in the cholesteric LC state and a two-dimensional crystal on substrate. The preferred-handed helical-sense and handedness excess of the copolymers in a Dilute Solution were sensitive to the solvent polarity and temperature, and amplification of the helical-sense excess was significantly affected by the solvents.

  • hierarchical amplification of macromolecular helicity of dynamic helical poly phenylacetylene s composed of chiral and achiral phenylacetylenes in Dilute Solution liquid crystal and two dimensional crystal
    Journal of the American Chemical Society, 2011
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Motonori Banno, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers consisting of optically active and achiral phenylacetylenes bearing l-alanine decyl esters (1L) and 2-aminoisobutylic acid decyl esters (Aib) as the pendant groups (poly(1Lm-co-Aibn)) with various compositions were synthesized by the copolymerization of the optically active 1L with achiral Aib using a rhodium catalyst, and their chiral amplification of the macromolecular helicity in a Dilute Solution, a lyotropic liquid crystalline (LC) state, and a two-dimensional (2D) crystal on the substrate was investigated by measuring the circular dichroism of the copolymers, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch), and high-reSolution atomic force microscopy (AFM) images of the self-assembled 2D helix-bundles of the copolymer chains. We found that the macromolecular helicity of poly(1Lm-co-Aibn)s could be hierarchically amplified in the order of the Dilute Solution, LC state, and 2D crystal. In sharp contrast, almost no chiral amplif...

Katsuhiro Maeda - One of the best experts on this subject based on the ideXlab platform.

  • amplification of macromolecular helicity of dynamic helical poly phenylacetylene s bearing non racemic alanine pendants in Dilute Solution liquid crystal and two dimensional crystal
    Polymer Journal, 2012
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers composed of non-racemic phenylacetylenes bearing L- and D-alanine decyl esters as the side groups (poly(1Lm-co-1Dn), m>n) were prepared by the copolymerization of the corresponding L- and D-phenylacetylenes with different enantiomeric excesses using a rhodium catalyst; their chiral amplification of the helical conformation as an excess of one-handedness in a Dilute Solution, in a lyotropic liquid-crystalline (LC) state and in a two-dimensional (2D) crystal on substrate was investigated by measuring the circular dichroism spectra of the copolymers at different temperatures, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch) and high-reSolution atomic force microscopy images of the self-assembled 2D helix-bundle structures of the copolymer chains, respectively. We have observed a unique amplification of the helical-sense excess (majority rule effect) of dynamic helical, liquid-crystalline (LC) poly(phenylacetylene)s bearing non-racemic D- and L-alanine residues as the pendant groups in a Dilute Solution, in the cholesteric LC state and a two-dimensional crystal on substrate. The preferred-handed helical-sense and handedness excess of the copolymers in a Dilute Solution were sensitive to the solvent polarity and temperature, and amplification of the helical-sense excess was significantly affected by the solvents.

  • hierarchical amplification of macromolecular helicity of dynamic helical poly phenylacetylene s composed of chiral and achiral phenylacetylenes in Dilute Solution liquid crystal and two dimensional crystal
    Journal of the American Chemical Society, 2011
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Motonori Banno, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers consisting of optically active and achiral phenylacetylenes bearing l-alanine decyl esters (1L) and 2-aminoisobutylic acid decyl esters (Aib) as the pendant groups (poly(1Lm-co-Aibn)) with various compositions were synthesized by the copolymerization of the optically active 1L with achiral Aib using a rhodium catalyst, and their chiral amplification of the macromolecular helicity in a Dilute Solution, a lyotropic liquid crystalline (LC) state, and a two-dimensional (2D) crystal on the substrate was investigated by measuring the circular dichroism of the copolymers, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch), and high-reSolution atomic force microscopy (AFM) images of the self-assembled 2D helix-bundles of the copolymer chains. We found that the macromolecular helicity of poly(1Lm-co-Aibn)s could be hierarchically amplified in the order of the Dilute Solution, LC state, and 2D crystal. In sharp contrast, almost no chiral amplif...

Kazuo Sakurai - One of the best experts on this subject based on the ideXlab platform.

  • β 1 3 d glucan schizophyllan poly da triple helical complex in Dilute Solution
    Journal of Physical Chemistry B, 2012
    Co-Authors: Yusuke Sanada, Tsubasa Matsuzaki, Shinichi Mochizuki, Tadashi Okobira, Kazuya Uezu, Kazuo Sakurai
    Abstract:

    A certain length of poly(deoxyadenylic acid) (dA(X)) can form a novel complex with β-1,3-D-glucan schizophyllan (SPG) with a stoichiometric composition of one dA binding two main chain glucoses. We measured Dilute Solution properties for the complex with light and small-angle X-ray scattering as well as intrinsic viscosity and found that the complex behaves as a semiflexible rod without branching or cross-linking. We analyzed the data with the wormlike cylinder model, and the chain dimensions and the persistence length for the complexes were consistently determined. The chain flexibility was reduced to almost 25% upon complexation for dA/SPG and to 15% for S-dA/SPG, where S-dA denotes the phosphorothioated DNA analogue. The changes in the molar mass per unit length and the diameter indicated that the helix was elongated or stretched along the axis direction upon the complexation.

  • β-1,3-d-Glucan Schizophyllan/Poly(dA) Triple-Helical Complex in Dilute Solution
    2012
    Co-Authors: Yusuke Sanada, Tsubasa Matsuzaki, Shinichi Mochizuki, Tadashi Okobira, Kazuya Uezu, Kazuo Sakurai
    Abstract:

    A certain length of poly(deoxyadenylic acid) (dAX) can form a novel complex with β-1,3-d-glucan schizophyllan (SPG) with a stoichiometric composition of one dA binding two main chain glucoses. We measured Dilute Solution properties for the complex with light and small-angle X-ray scattering as well as intrinsic viscosity and found that the complex behaves as a semiflexible rod without branching or cross-linking. We analyzed the data with the wormlike cylinder model, and the chain dimensions and the persistence length for the complexes were consistently determined. The chain flexibility was reduced to almost 25% upon complexation for dA/SPG and to 15% for S-dA/SPG, where S-dA denotes the phosphorothioated DNA analogue. The changes in the molar mass per unit length and the diameter indicated that the helix was elongated or stretched along the axis direction upon the complexation

Sousuke Ohsawa - One of the best experts on this subject based on the ideXlab platform.

  • amplification of macromolecular helicity of dynamic helical poly phenylacetylene s bearing non racemic alanine pendants in Dilute Solution liquid crystal and two dimensional crystal
    Polymer Journal, 2012
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers composed of non-racemic phenylacetylenes bearing L- and D-alanine decyl esters as the side groups (poly(1Lm-co-1Dn), m>n) were prepared by the copolymerization of the corresponding L- and D-phenylacetylenes with different enantiomeric excesses using a rhodium catalyst; their chiral amplification of the helical conformation as an excess of one-handedness in a Dilute Solution, in a lyotropic liquid-crystalline (LC) state and in a two-dimensional (2D) crystal on substrate was investigated by measuring the circular dichroism spectra of the copolymers at different temperatures, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch) and high-reSolution atomic force microscopy images of the self-assembled 2D helix-bundle structures of the copolymer chains, respectively. We have observed a unique amplification of the helical-sense excess (majority rule effect) of dynamic helical, liquid-crystalline (LC) poly(phenylacetylene)s bearing non-racemic D- and L-alanine residues as the pendant groups in a Dilute Solution, in the cholesteric LC state and a two-dimensional crystal on substrate. The preferred-handed helical-sense and handedness excess of the copolymers in a Dilute Solution were sensitive to the solvent polarity and temperature, and amplification of the helical-sense excess was significantly affected by the solvents.

  • hierarchical amplification of macromolecular helicity of dynamic helical poly phenylacetylene s composed of chiral and achiral phenylacetylenes in Dilute Solution liquid crystal and two dimensional crystal
    Journal of the American Chemical Society, 2011
    Co-Authors: Sousuke Ohsawa, Katsuhiro Maeda, Shinichiro Sakurai, Kanji Nagai, Motonori Banno, Jiro Kumaki
    Abstract:

    Optically active poly(phenylacetylene) copolymers consisting of optically active and achiral phenylacetylenes bearing l-alanine decyl esters (1L) and 2-aminoisobutylic acid decyl esters (Aib) as the pendant groups (poly(1Lm-co-Aibn)) with various compositions were synthesized by the copolymerization of the optically active 1L with achiral Aib using a rhodium catalyst, and their chiral amplification of the macromolecular helicity in a Dilute Solution, a lyotropic liquid crystalline (LC) state, and a two-dimensional (2D) crystal on the substrate was investigated by measuring the circular dichroism of the copolymers, mesoscopic cholesteric twist in the LC state (cholesteric helical pitch), and high-reSolution atomic force microscopy (AFM) images of the self-assembled 2D helix-bundles of the copolymer chains. We found that the macromolecular helicity of poly(1Lm-co-Aibn)s could be hierarchically amplified in the order of the Dilute Solution, LC state, and 2D crystal. In sharp contrast, almost no chiral amplif...

Yusuke Sanada - One of the best experts on this subject based on the ideXlab platform.

  • β 1 3 d glucan schizophyllan poly da triple helical complex in Dilute Solution
    Journal of Physical Chemistry B, 2012
    Co-Authors: Yusuke Sanada, Tsubasa Matsuzaki, Shinichi Mochizuki, Tadashi Okobira, Kazuya Uezu, Kazuo Sakurai
    Abstract:

    A certain length of poly(deoxyadenylic acid) (dA(X)) can form a novel complex with β-1,3-D-glucan schizophyllan (SPG) with a stoichiometric composition of one dA binding two main chain glucoses. We measured Dilute Solution properties for the complex with light and small-angle X-ray scattering as well as intrinsic viscosity and found that the complex behaves as a semiflexible rod without branching or cross-linking. We analyzed the data with the wormlike cylinder model, and the chain dimensions and the persistence length for the complexes were consistently determined. The chain flexibility was reduced to almost 25% upon complexation for dA/SPG and to 15% for S-dA/SPG, where S-dA denotes the phosphorothioated DNA analogue. The changes in the molar mass per unit length and the diameter indicated that the helix was elongated or stretched along the axis direction upon the complexation.

  • β-1,3-d-Glucan Schizophyllan/Poly(dA) Triple-Helical Complex in Dilute Solution
    2012
    Co-Authors: Yusuke Sanada, Tsubasa Matsuzaki, Shinichi Mochizuki, Tadashi Okobira, Kazuya Uezu, Kazuo Sakurai
    Abstract:

    A certain length of poly(deoxyadenylic acid) (dAX) can form a novel complex with β-1,3-d-glucan schizophyllan (SPG) with a stoichiometric composition of one dA binding two main chain glucoses. We measured Dilute Solution properties for the complex with light and small-angle X-ray scattering as well as intrinsic viscosity and found that the complex behaves as a semiflexible rod without branching or cross-linking. We analyzed the data with the wormlike cylinder model, and the chain dimensions and the persistence length for the complexes were consistently determined. The chain flexibility was reduced to almost 25% upon complexation for dA/SPG and to 15% for S-dA/SPG, where S-dA denotes the phosphorothioated DNA analogue. The changes in the molar mass per unit length and the diameter indicated that the helix was elongated or stretched along the axis direction upon the complexation