Cation binding properties of poly(crown ether)s with photodimerizable groups. Enhanced cation binding ability via a photochemical template effect

Shirai, Masamitsu; Ueda, Akihiko; Tanaka, Makoto

doi:10.1002/macp.1985.021860306

Cited by 24 publications

(4 citation statements)

References 18 publications

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“…In the literature, lithium ions are frequently used as templates in crown ether relateds tructures. [16] Therefore, lithium ions were added to bind to the oxygen atomso ft he hexaethylene glycol chain to bring the two double bonds in 3b closer together.A fter adding lithium perchlorate in high excess, irradiation with ah igh-pressurem ercury lamp produced cyclobutane 4b in 95 %y ield.…”

Section: Syntheses Of Cyclobutane Macrocyclesmentioning

confidence: 99%

Mechanochemical Cycloreversion of Cyclobutane Observed at the Single Molecule Level

Pill

Holz

Preußke

et al. 2016

Chemistry A European J

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Mechanochemical cycloreversion of cyclobutane is known from ultrasound experiments. It is, however, not clear which forces are required to induce the cycloreversion. In atomic force microscopy (AFM) experiments, on the other hand, it is notoriously difficult to assign the ruptured bond. We have solved this problem through the synthesis of tailored macrocycles, in which the cyclobutane mechanophore is bypassed by an ethylene glycol chain of specific length. This macrocycle is covalently anchored between a glass substrate and an AFM cantilever by polyethylene glycol linkers. Upon mechanical stretching of the macrocycle, cycloreversion occurs, which is identified by a defined length increase of the stretched polymer. The measured length change agrees with the value calculated with the external force explicitly included (EFEI) method. By using two different lengths for the ethylene glycol safety line, the assignment becomes unambiguous. Mechanochemical cycloreversion of cyclobutane is observed at forces above 1.7 nN.

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Section: Syntheses Of Cyclobutane Macrocyclesmentioning

confidence: 99%

Mechanochemical Cycloreversion of Cyclobutane Observed at the Single Molecule Level

Pill

Holz

Preußke

et al. 2016

Chemistry A European J

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“…128,151,164 Various classes of crown ethers attached to polymers have been of interest due to their selective ionic binding of complexes with metal cations. [190][191][192][193][194] π-Conjugated polymers such as polypyrroles 192,195 and polythiophenes 196,197 functionalized with crown ether were extensively investigated to explore the ion-selective electrodes and sensory materials. The polymerization of 4′,4′-ethynylbenzo-1,5-crown-5 was carried out using the rhodium complex catalyst (bicyclo[2.2.1]hepta-2,5-diene)rhodium(I) chloride dimer, [Rh(bhd)-Cl 2 ], 197,198 to give a maximum 55% yield of a polymer.…”

Section: A Poly(16-heptadiyne) and Its Homologuesmentioning

confidence: 99%

Poly(1,6-heptadiyne)-Based Materials by Metathesis Polymerization

et al. 2000

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A new class of multifunctional polymers based on poly(l,6heptadiyne) derivatives with various functional groups such as carbazole unit for photoconductive polymers and nonlinear optical (NLO) chromophores for NLO polymers were synthesized by metathesis polymerization. The polymerizations were carried out with MoCI,-and WCI,-based catalysts. The catalytic activity of MoCI, was found to be greater than that of WCI , . The resulting polymers exhibited photoconductivity and large optical nonlinearity. These conjugated polymers have good solubility in common organic solvents, long-term stability toward air oxidation, and high electrical conductivity.

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“…Metal extracting efficiencies were evaluated from distribution equilibria of picrate ions between aqueous phase and organic phases. 13 The transfer of picric acid from the aqueous phase was little for the solution of Copoly-I. The amount of azobenzene unit in the polymer is less than several percent, thereby it is difficult for two pendant azobenzenes to cooperate intermolecularly.…”

Section: Synthesis Of Azobenzene Polymer and Its Metalmentioning

confidence: 99%

Synthesis and Photoregulated Metal Coordination of Azobenzene Polymer Having Ion Binding Sites

Nanasawa

Nishiyama

Kamogawa

1991

Polym J

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ABSTRACT:Vinyl polymers having pendant 3,3'-substituted azobenzene were synthesized. Selective metal extracting ability was found in the photoisomerized polymers having bisiminodiacetic acid groups. The selectivity was large in the azobenzene with directly connected imino-groups rather than those having the methylene chain spacers between the rings and imino-groups. The metal coordination was not strong, so that the complexed cis-isomer thermally recovered to the trans one. The reversible transformation suggests possible applications for photo regulated macromolecular ionophores.KEY WORDS Azobenzene Polymer / Photoisomerization / Metal Extraction / Photo regulated Macromolecular Ionophore / Azobenzene and many of its derivatives exhibit large confomational change by reversible trans-cis transformation. A number of polymers having azobenzene moieties have been synthesized and their photo-induced isomerization has received much attention for functions as photoresponsive polymer, including the change of viscosity, pH, conductivity, solubility, wettability, and mechanical properties. 1 Recently some azobenzene derivatives having two iminodiacetic acid groups2,3 and a variety of crown ethers 4 at both 4,4' -position have been synthesized to mimic the behavior of reversible ion binding affinity in biological systems; their ion binding properties have been controlled by photo-induced trans-cis isomerization.The authors have been interested in the synthesis of vinyl polymers having azobenzene moieteis with ionic metal binding sites and the behavior of their metal extracting ability. The rate of isomerization is reduced if a substituent group at 2-and/or 4-position would contribute to the resonance stabilization of azidostructures and if a proton donating groups at 2-position would make hydrogen bonds with adjacent azo-group.5,6 In order to enhance the reversible trans-cis transformation, metal binding ligands are connected at the 3-position of both phenyl rings in spite of two substituent groups existing in anti-and syn-configuration on azobenzene rings. The distance between two carbons at 3,3'-position of non planar cisisomer is below 5 A. 7 Therefore two substituent groups become feasible to interact each other compared with those in trans-isomer and 4,4'-ones in cis-azobenzene. However, two ligands in the cis-isomer should moderately bind with metal ions, because the very stable complex stabilizes the cis-form and can not release the ion efficiently on the reverse transformation. We thus synthesized low molecular weight compounds designed by a space filling molecular model, in which for the cis-isomer the negatively charged oxygen ligands could be brought close to metal ions enough to bind intramoleclarly. However, this binding is not possible or much weaker in the planar trans-form.The low molecular weight azo-compounds 127

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Cation binding properties of poly(crown ether)s with photodimerizable groups. Enhanced cation binding ability via a photochemical template effect

Cited by 24 publications

References 18 publications

Mechanochemical Cycloreversion of Cyclobutane Observed at the Single Molecule Level

Mechanochemical Cycloreversion of Cyclobutane Observed at the Single Molecule Level

Poly(1,6-heptadiyne)-Based Materials by Metathesis Polymerization

Synthesis and Photoregulated Metal Coordination of Azobenzene Polymer Having Ion Binding Sites

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