Helicity Induction and Conformational Dynamics of Poly(bis(4-carboxyphenoxy)phosphazene) with Optically Active Amines

Yashima, Eiji; Maeda, and Katsuhiro; Yamanaka, Toshio

doi:10.1021/ja994156e

Cited by 75 publications

(55 citation statements)

References 26 publications

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“…In fact, similar helicity induction in the presence of chiral molecules capable of noncovalently interacting with the polymer×s functional groups was achieved for aliphatic polyacetylenes (10,11), [25] polyphosphazene (12), [26] polyisocyanate (13), [27] polyguanidine (14), [28] and polyisocyanide (15) [29] by our group or others. [33] Inai et al took advantage of the helicity induction concept combined with the structural feature of an achiral oligopeptide (16) as a template to induce a predominantly one-handed helix by chiral carboxylic acids.…”

Section: Chirality Sensing By Supramolecular Systemssupporting

confidence: 67%

Detection and Amplification of Chirality by Helical Polymers

Yashima

Maeda

Nishimura

2003

Chemistry A European J

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534

302

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A unique feature of synthetic helical polymers for the detection and amplification of chirality is briefly described in this article. In sharp contrast to host-guest and supramolecular systems that use small synthetic receptor molecules, chirality can be significantly amplified in a helical polymer, such as poly(phenylacetylene)s with functional pendants, which enable the detection of a tiny imbalance in biologically important chiral molecules through a noncovalent bonding interaction with high cooperativity. The rational design of polymeric receptors can be possible by using chromophoric helical polymers combined with functional groups as the pendants, which target particular chiral guest molecules for developing a highly efficient chirality-sensing system. The chirality sensing of other small molecular and supramolecular systems is also briefly described for comparison.

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Section: Chirality Sensing By Supramolecular Systemssupporting

confidence: 67%

Detection and Amplification of Chirality by Helical Polymers

Yashima

Maeda

Nishimura

2003

Chemistry A European J

Self Cite

534

302

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“…Macromolecules with secondary structural ordering have also been prepared using monomers carrying pendant chiral groups [20][21][22][23][24]. Additionally, helical polymers have been prepared by generating secondary conformations by helicity induction [25][26][27][28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Optically Active Helical Poly(2-methoxystyrene). Enhancement of HeLa and Osteoblast Cell Growth on Optically Active Helical Poly(2-methoxystyrene) Surfaces

Gordon

Sannigrahi

McGeady

et al. 2009

Journal of Biomaterials Science, Polymer Edition

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Poly(2-methoxystyrene)s (P2MS) were synthesized using n-BuLi in THF and toluene at various temperatures. At -20 degrees C and higher temperatures, toluene was an effective polymerization solvent for synthesizing poly(2-methoxystyrene). Under these conditions, polymers with good yields and reasonable molecular weight distributions were obtained. Polymers synthesized under all conditions were isotactic; the most highly isotactic polymer was obtained in toluene at -20 degrees C. The m (isotactic dyad) content of the polymers synthesized in toluene at 0 degrees C and -20 degrees C was 0.65 and 0.74, respectively. Optically active helical (+) and (-) P2MS were synthesized by asymmetric polymerization utilizing (+) or (-) [2,3-dimethoxy1,4(dimethylamino)butane] (DDB)/tolyl lithium initiating complex in toluene. Asymmetric polymerizations were also carried out at 0 degrees C to synthesize optically active polymers. The optical rotations of the polymers were found to be dynamic and reversible, strongly suggesting contribution of the chiral higher ordered structure to the overall optical rotation. Geometry optimization carried out using various force fields such as MM+, AMBER and CHARMM suggests that isotactic P2MS form low energy stable helical conformations. HeLa cells showed better growth on surfaces prepared using chiral polymers compared to the surfaces prepared with achiral polymers. Similarly, chiral P2MS surfaces were also more effective as supports for mouse and human osteoblast cells. The cell attachment and growth data demonstrate that chiral P2MS surfaces were better supports compared to achiral P2MS surfaces. Atomic force microscopy (AFM) studies on surfaces prepared using chiral poly(2-methoxystyrene) showed more discrete topography features compared to surfaces prepared with achiral polymers. Thus, the surface topography may play a role in determining polymer-cell interactions.

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“…[15][16][17][18][19] Another approach is the use of external chiral stimuliinduced or chiral field-induced transformation from a racemic helical or achiral polymer to an enantioenriched helical polymer. In this approach, the chiral helical bias has often been induced by strong interactions such as acid-base interactions [20][21][22][23][24][25] and host-guest interactions [26][27][28][29][30][31] between a chiral molecule and a polymer. In these cases, the polymer requires a functional group to interact with the chiral molecule, which may restrict the molecular design of optically active functional polymers.…”

Section: Introductionmentioning

confidence: 99%

Transformation from preformed racemic helical poly(phenylacetylene)s to the enantioenriched helical polymers by chiral solvation, followed by removal of the chiral solvents

Kaneko

Liang

Kawami

et al. 2012

Polym J

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Homochiral or enantioenriched helical polymers are essential for investigating the relationship between chirality of helical structures and their performance in the design of various optically active functional polymers. We have succeeded in obtaining the helical poly(phenylacetylene)s poly(1)-poly(6) possessing no chiral moieties, except for helicity; the enantioenriched helical sense of these polymers was induced by transformation in chiral solvents, followed by removal of the chiral solvents, even if the interaction between the chiral molecule and the polymer was weak such as solvent-solute interaction. In particular, the newly synthesized poly(6) retained the induced helical sense even in an achiral solvent.

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Helicity Induction and Conformational Dynamics of Poly(bis(4-carboxyphenoxy)phosphazene) with Optically Active Amines

Cited by 75 publications

References 26 publications

Detection and Amplification of Chirality by Helical Polymers

Detection and Amplification of Chirality by Helical Polymers

Synthesis of Optically Active Helical Poly(2-methoxystyrene). Enhancement of HeLa and Osteoblast Cell Growth on Optically Active Helical Poly(2-methoxystyrene) Surfaces

Transformation from preformed racemic helical poly(phenylacetylene)s to the enantioenriched helical polymers by chiral solvation, followed by removal of the chiral solvents

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