Selective Synthesis and Kinetic Measurement of 1:1 and 2:2 Cyclic Compounds Containing 1,4,7,10-Tetraazacyclododecane and Azobenzene Units

Wh, Wei; Tomohiro, Takenori; Kodaka, Masato; Okuno, Hiroaki

doi:10.1021/jo000926p

Cited by 64 publications

(59 citation statements)

References 17 publications

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“…The attachment went through its chloride (14) and gave 15 in virtually quantitative yields (Scheme 5). Saponification of the focal point ester of 15 cleanly furnished 16.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Water‐Soluble, Multiple Functionalizable Dendrons for the Conversion of Large Dendrimers or Other Molecular Objects into Potential Drug Carriers

Müller

Schlüter

2005

Chemistry A European J

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The synthesis of dendrons and dendrimers which carry OEG chains and bidentate ligands and/or fluorescence tags is described. The orthogonally protected functional groups of the dendrons allow modification of the substitution pattern and attachment to larger entities. Both dendrons and dendrimers are highly water-soluble. The dendrons should have considerable potential to convert, for example, commercially available, high-generation dendrimers into water-soluble, versatile support materials for antitumor therapy.

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“…The attachment went through its chloride (14) and gave 15 in virtually quantitative yields (Scheme 5). Saponification of the focal point ester of 15 cleanly furnished 16.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Water‐Soluble, Multiple Functionalizable Dendrons for the Conversion of Large Dendrimers or Other Molecular Objects into Potential Drug Carriers

Müller

Schlüter

2005

Chemistry A European J

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“…The amphiphilic compound Azo [10] and the g-Fe 2 O 3 nanoparticles [11] were synthesized according to literature methods. 1: FeCl 3 ·6 H 2 O (0.47 g), sodium acetate (0.43 g, used as a hydrolyzing agent), H 2 O (0.35 ml), n-octylamine (0.61 mL), and Azo (0.01 g) in 1,2-propanediol (6 mL) were heated under reflux at 150 8C for 5 h. The materials were then precipitated by the addition of a large volume of 2-propanol (ca.…”

Section: Methodsmentioning

confidence: 99%

“…In addition to encapsulating the surface of the g-Fe 2 O 3 nanoparticles with the azo moiety, we incorporated n-octylamine. The amphiphilic azo compound 8-[4-{4-butoxy-phenyl(azo)-phenoxy}octan-1-ol] (Azo) was synthesized according to literature methods [10] and then used to prepare the photo-responsive composite magnetic nanoparticles 1 (see the Experimental Section).…”

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confidence: 99%

Reversible Photo‐Switching of the Magnetization of Iron Oxide Nanoparticles at Room Temperature

et al. 2004

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Optically switchable magnetic materials are becoming increasingly important in the field of high-density information storage media. [1][2][3] We have been trying to prepare new types of magnets in which the magnetic properties can be controlled by photo-illumination. Our previous work has shown that cobalt-iron cyanide exhibits photoinduced magnetization effects due to an internal electron transfer.[4] However, practical examples of such photo-magnetic systems are limited in number [5] because the strategies that are necessary to achieve photoinduced switching in the solid state are yet to be clarified.The use of organized organic assemblies to direct the formation of mesoscopic inorganic structures under mild conditions and the attempts to intercalate inorganic materials into functional organic molecules are also of topical interest. [6] We have focused our attention on composite materials as a novel strategy for realizing such photo-functional magnetic systems. These include the incorporation of organic photochromes into magnetic systems, for example, photo-controllable magnetic vesicles and Langmuir-Blodgett films containing Prussian blue (a ferromagnet at low temperature) and azobenzene. [7] Although the examples described above show interesting photo-responsive phenomena, the results were only achieved at low temperature. It is evident that the temperature at which photo-switching occurs needs to be increased to room temperature in order to realize devices for practical applications. In the present work we have focused on iron oxide

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“…The key in this work is appropriate design of the guest azobenzene molecule, in which modification of azobenzene with poly-(ethylene glycol) (PEG) at the 4,4¤-position affords large differences in the shape and solubility upon cistrans isomerization. In this system, irradiation with UV and visible light could reversibly switch the hostguest adsorption as a result of isomerization of the PEG-tethered azobenzene (PEG-AB) (Figure 1).PEG-AB was synthesized by the reaction of 4,4¤-dihydroxyazobenzene 16 with tetra(ethylene glycol) monomethyl ether tosylate. 17 We prepared various PEG-AB solutions, such as MeOH, EtOH, acetone, n-hexane, tetrahydrofuran, dimethylformamide, dichloromethane, toluene, diethyl ether, and 1,4-dioxane, and attempted to incorporate PEG-AB into 1 via liquid-phase adsorption (Figure 2).…”

mentioning

confidence: 99%

“…PEG-AB was synthesized by the reaction of 4,4¤-dihydroxyazobenzene 16 with tetra(ethylene glycol) monomethyl ether tosylate. 17 We prepared various PEG-AB solutions, such as MeOH, EtOH, acetone, n-hexane, tetrahydrofuran, dimethylformamide, dichloromethane, toluene, diethyl ether, and 1,4-dioxane, and attempted to incorporate PEG-AB into 1 via liquid-phase adsorption ( Figure 2).…”

mentioning

confidence: 99%

Controlled Encapsulation of Photoresponsive Macromolecules in Porous Coordination Polymer

et al. 2013

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A photoresponsive controlled adsorption system based on a porous coordination polymer (PCP) was fabricated, using azobenzene tethered with poly(ethylene glycol) (PEG-AB) as macromolecular guests. Specific adsorption behavior of trans-PEG-AB into the nanochannels of a PCP was observed in an EtOH medium. When this composite was irradiated with UV light in EtOH, isomerization of PEG-AB from the trans to the cis form resulted in release of PEG-AB because of the large changes in the molecular shape and solubility of PEG-AB. Subsequent visible light irradiation induced photoisomerization of PEG-AB, which led to readsorption of PEG-AB into the nanochannels.In recent years, controllable encapsulationrelease systems using porous and capsule materials operated by external stimuli, such as heat, pH, and light, have attracted great interest in materials science.14 Intelligent hostguest systems that can be reversibly switched in a controlled manner have enormous potential for innovative applications such as in energy harvesting and storage, in controlled-release delivery of drugs, and in the development of nanoscale optical and molecular electronics devices. 57Porous coordination polymers (PCPs), composed of metal ions and bridging organic ligands, have recently emerged as an important family of porous materials because of their unique structural and functional properties. 812 PCPs have highly regular and designable nanopores that can be used for storage, separation, and catalysis. In particular, developing new PCPbased carrier systems for controlled release is of current interest.13,14 Because of their nontoxic nature, imaging properties, and capability for large drug loadings, PCPs are suitable candidates as drug-delivery carriers. 13,14Herein, we report a photoresponsive reversible encapsulationrelease system using [Zn 2 (terephthalate) 2 (triethylenediamine)] (1) 15 and an azobenzene derivative (Figure 1). The key in this work is appropriate design of the guest azobenzene molecule, in which modification of azobenzene with poly-(ethylene glycol) (PEG) at the 4,4¤-position affords large differences in the shape and solubility upon cistrans isomerization. In this system, irradiation with UV and visible light could reversibly switch the hostguest adsorption as a result of isomerization of the PEG-tethered azobenzene (PEG-AB) (Figure 1).PEG-AB was synthesized by the reaction of 4,4¤-dihydroxyazobenzene 16 with tetra(ethylene glycol) monomethyl ether tosylate. 17 We prepared various PEG-AB solutions, such as MeOH, EtOH, acetone, n-hexane, tetrahydrofuran, dimethylformamide, dichloromethane, toluene, diethyl ether, and 1,4-dioxane, and attempted to incorporate PEG-AB into 1 via liquid-phase adsorption (Figure 2). Successful incorporation of PEG-AB was only observed in EtOH, where the yellow-colored solution of PEG-AB became colorless after mixing with 1 (Figure 2). This is probably because of the relatively low solubility of PEG-AB in EtOH compared with the other solvents. The resulting yellow precipitate was isolated by filtr...

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Selective Synthesis and Kinetic Measurement of 1:1 and 2:2 Cyclic Compounds Containing 1,4,7,10-Tetraazacyclododecane and Azobenzene Units

Cited by 64 publications

References 17 publications

Synthesis of Water‐Soluble, Multiple Functionalizable Dendrons for the Conversion of Large Dendrimers or Other Molecular Objects into Potential Drug Carriers

Synthesis of Water‐Soluble, Multiple Functionalizable Dendrons for the Conversion of Large Dendrimers or Other Molecular Objects into Potential Drug Carriers

Reversible Photo‐Switching of the Magnetization of Iron Oxide Nanoparticles at Room Temperature

Controlled Encapsulation of Photoresponsive Macromolecules in Porous Coordination Polymer

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