Chiral Supramolecular Polymers Formed by Host−Guest Interactions

Miyauchi, Masahiko; Takashima, Yoshinori; Yamaguchi, Hiroyasu; Harada, Akira

doi:10.1021/ja043289j

Cited by 202 publications

(130 citation statements)

References 21 publications

Supporting

Mentioning

121

Contrasting

Unclassified

Order By: Relevance

“…Among polyrotaxanes as one of the interlocked polymers (Figure 1), both poly [2]rotaxane [21][22][23][24][25][26][27][28][29][30][31][32][33] and poly [3]rotaxane 34,35 are specially unique as characterized by their structural feature that the polymer main chain has no successive covalent bond. The repeating units of these polymers are bound by mechanical bonds.…”

mentioning

confidence: 99%

Synthesis and Characterization of Poly[3]rotaxane through the Mizoroki-Heck Coupling Polymerization of Divinyl-functionalized [3]Rotaxane

Sato

Takata

2009

Polym. J.

View full text Add to dashboard Cite

Main chain-type poly [3]rotaxanes were synthesized according to the rotaxanation-polymerization protocol by the polymerization of a divinyl [3]rotaxane monomer through the Mizoroki-Heck coupling with a diiodoarene. [3]Rotaxane 5 consisting of two monovinyl dibenzo-24-crown-8-ether wheels (2) and sec-ammonium salt (3) as an axle component was synthesized in 86% yield by a typical urethane end-capping reaction of the axle terminal hydroxyl group with bis(4-isocyanophenyl)methane in the presence of a catalytic amount of di-n-butyltin dilaurate. Quantitative N-acetylation of 5 yielded mono(vinylphenyl)-functionalized wheel-containing [3]rotaxane monomers 6. The mobility of the wheel components in [3]rotaxanes was evaluated by the two-dimention NOESY spectra of 5 and 6. The main-chain type poly[3]rotaxanes 8 were obtained in high yields by the Mizoroki-Heck-type polycondensation of 6 and diiodoarenes 7 in the presence of a palladium catalyst (Pd(OAc) 2 ). The structures of the polyrotaxanes were determined mainly by NMR and GPC, while the IR spectra showed that vinylene groups formed mainly took the trans configuration. Properties of the polyrotaxanes such as solubility and thermal stability were evaluated. Interlocked polymers, 1-20 a novel class of polymers containing mechanical linkages consisting of wheels and/or axle components, are expected to display unique properties such as mechanical and rheological ones. Among polyrotaxanes as one of the interlocked polymers (Figure 1) 34,35 are specially unique as characterized by their structural feature that the polymer main chain has no successive covalent bond. The repeating units of these polymers are bound by mechanical bonds. Meanwhile, there is few report on polyrotaxane with the backbone consisting of mechanical bonds, i.e., topologically linked polymer backbone, in contrast to poly[2]catenanes. [36][37][38][39][40][41][42][43][44][45][46] We previously reported the synthesis of poly[3]rotaxane utilizing the reversible cleavage-recombination process of the disulfide bond in the precense of a catalystic amount of thiol under thermodynamic control. 34 Further, we have recently disclosed the synthesis of poly[2]rotaxane by the polymerization of a bifunctional rotaxane monomer via the Sonogashira coupling reaction, 47 while a few poly[2]rotaxanes were synthesized by the thermaldynamic process. 21,22,[24][25][26][27][28] There are two possible ways accessing the main chain-type poly[3]-rotaxane: one goes through the initial rotaxanation followed by the polymerization (Figure 2, route A), whereas the other undergoes the initial coupling of wheel followed by the rotaxanation to poly[3]rotaxane (Figure 2, route B), as shown in Figure 1. Our previous paper 33 described the synthesis of a polyrotaxane by rotaxanation of ditopic wheel component utilizing the dynamic covalent chemistry of disulfide linkage, along Route B.In this paper, the synthesis of poly [3]rotaxanes by polycondensation via the Mizoroki-Heck coupling of diviynylfunctionalized [3]rotaxane and diiodoarenes,...

show abstract

mentioning

confidence: 99%

Synthesis and Characterization of Poly[3]rotaxane through the Mizoroki-Heck Coupling Polymerization of Divinyl-functionalized [3]Rotaxane

Sato

Takata

2009

Polym. J.

View full text Add to dashboard Cite

show abstract

“…The nanoparticles were sunk inside and the height of the nanoparticles was about 0.8 nanometers, which was nearly the same height as one α-cyclodextrin. 30,31 The wall thickness of the sunk nanoparticles measured by AFM was about 20 nanometers ( Figure 3D). Both TEM and AFM images demonstrated that the blank polyrotaxane nanoparticles were hollow with vesicle-like morphology.…”

Section: Resultsmentioning

confidence: 99%

Supramolecular nanoparticles generated by the self-assembly of polyrotaxanes for antitumor drug delivery

Liu¹,

Lai²,

He³

et al. 2012

IJN

View full text Add to dashboard Cite

Abstract:A new approach of fabricating supramolecular nanoparticles generated by selfassembly polyrotaxanes for antitumor drug delivery has been reported. Cinnamic-acid-modified poly(ethylene glycol) chains were threaded in α-cyclodextrins to form polyrotaxanes. The polyrotaxanes self-assembled supramolecular nanoparticles. The morphology of the nanoparticles was changed from nanovesicle to micelle after the antitumor drug, doxorubicin, was loaded. The release profile of the drug-loaded nanoparticles was investigated, and it was found that the sustaining release time could last for 32 hours. The drug-loaded nanoparticles were co-cultured with mouse 4T1 breast cancer cells with a drug concentration of 10 µg/mL; the cell survival rate was 3.3% after a 72-hour incubation. In an in vivo study of breast cancer in a mouse model, the drug-loaded nanoparticles were injected in the tail veins of mice with a dose of 5 mg/kg body weight. The tumor inhibition rate of drug-loaded nanoparticles was 53%, which was better than that of doxorubicin hydrochloride. The cardiac toxicity of doxorubicin was decreased greatly after the encapsulation into supramolecular polyrotaxane nanoparticles.

show abstract

“…23 In this case, motion was triggered by solvent effects and not by photoisomerization processes, although the compounds contain stilbene groups. Harada and his team first showed that 6-cinnamamide-α-cyclodextrin and 6-aminocinnamate-α-cyclodextrin led to a doubly-threaded dimer.…”

mentioning

confidence: 94%

Molecular Muscles: From Species in Solution to Materials and Devices

2014

View full text Add to dashboard Cite

The field of “molecular machines” based on interlocking ring compounds started about twenty years ago with the deliberate synthesis of molecules or molecular assemblies which could be set in motion using various types of signals (mostly photonic, electrochemical, or chemical). The complexity of the systems gradually increased and, twelve years ago, rotaxane dimers whose length could be controlled were proposed. At that time, they were among the most sophisticated machines. In the present review article, we present a survey of the most significant systems published since the beginning of nanosize molecular muscles. The doubly threaded nature of rotaxane dimers consisting of two “ring-and-string” fragments with the ring of one fragment being threaded by the thread of the other fragment, and vice versa, is certainly very well adapted to contraction and elongation motions. The various muscle-like species discussed are based on significantly different principles: coordination chemistry, the transition metals used playing a central role, hydrophobic forces combined with photoisomerization processes or solvent effects when the threaded rings were cyclodextrins, hydrogen bonding and acceptor–donor interactions, the movement being driven by a pH change in this latter case. Particularly promising extensions of the field have been reported in recent years. In a very significant example, contraction and extension of surface-bound “molecular muscles” was shown to induce the bending of a beam that is five orders of magnitude larger in size than the molecular species itself. In the most recent contribution, preparation of a polymer from an elemental nanosize molecular muscle was achieved, leading to a long molecular fragment able to undergo contraction and elongation under well-controlled conditions. The corresponding material, formed by the association of thousands of molecular muscles, was shown to behave as a contractile and extensible system at the macroscopic level.

show abstract

Chiral Supramolecular Polymers Formed by Host−Guest Interactions

Cited by 202 publications

References 21 publications

Synthesis and Characterization of Poly[3]rotaxane through the Mizoroki-Heck Coupling Polymerization of Divinyl-functionalized [3]Rotaxane

Synthesis and Characterization of Poly[3]rotaxane through the Mizoroki-Heck Coupling Polymerization of Divinyl-functionalized [3]Rotaxane

Supramolecular nanoparticles generated by the self-assembly of polyrotaxanes for antitumor drug delivery

Molecular Muscles: From Species in Solution to Materials and Devices

Contact Info

Product

Resources

About