Rotaxane Assemblies with Dendritic Architecture

Osswald, Friederike; Vogel, Erik; Safarowsky, Oliver; Schwanke, Frank; Vögtle, Fritz

doi:10.1002/1615-4169(20010330)343:3<303::aid-adsc303>3.0.co;2-g

Cited by 24 publications

(4 citation statements)

References 6 publications

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“…The intrinsic complexity of type III-B RDs (T3B-RDs) and steric hindrance with hyperbranched mechanical bonds render the formation of higher generation (G > 2) T3B-RDs rather difficult, thus poses as a greater synthetic challenge than the type III-A RDs 21 , 22 . The earliest example of first generation (G1) T3B-RD was reported by Vögtle colleagues 23 . We reported the first facile synthesis of prototypical G2 type III-B rotaxane dendrons in 2013 24 .…”

Section: Introductionmentioning

confidence: 99%

Higher-generation type III-B rotaxane dendrimers with controlling particle size in three-dimensional molecular switching

et al. 2018

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Type III-B rotaxane dendrimers (T3B-RDs) are hyperbranched macromolecules with mechanical bonds on every branching unit. Here we demonstrate the design, synthesis, and characterization of first to third (G1–G3), and up to the fourth (G4) generation (MW > 22,000 Da) of pure organic T3B-RDs and dendrons through the copper-catalyzed alkyne–azide cycloaddition (CuAAC) reaction. By utilizing multiple molecular shuttling of the mechanical bonds within the sphere-like macromolecule, a collective three-dimensional contract-extend molecular motion is demonstrated by diffusion ordered spectroscopy (DOSY) and atomic force microscopy (AFM). The discrete T3B-RDs are further observed and characterized by AFM, dynamic light scattering (DLS), and mass spectrometry (MS). The binding of chlorambucil and pH-triggered switching of the T3B-RDs are also characterized by 1H-NMR spectroscopy.

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Section: Introductionmentioning

confidence: 99%

Higher-generation type III-B rotaxane dendrimers with controlling particle size in three-dimensional molecular switching

et al. 2018

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“…Covalent attachment of multiwalled carbon nanotubes through ruthenium diimine linkage shows the potential of CNT assembly . Our aim is to functionalize CNTs with large rigid molecular systems that can mechanically , dock to, or about, the nanoparticle. The advantage of this approach is that it may be possible to connect nanotubes and nanowires together into topologically stable and morphologically static three-dimensional (3D) assemblies.…”

Section: Introductionmentioning

confidence: 99%

Binding of Rigid Dendritic Ruthenium Complexes to Carbon Nanotubes

Chaturvedi

Poler

2006

J. Phys. Chem. B

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Single-walled carbon nanotubes (SWNTs) bind strongly to rigid ruthenium metallodendrimers. High valence ions effectively coagulate these nanotubes from stable dispersions in N,N-dimethylforamide. While ruthenium salts and small [Ru(diimine)(3)](2+) complexes also coagulate the nanotubes, they require much higher concentrations and are easily extracted from the nanotubes with acetonitrile. Enantiomerically pure ruthenium metallodendrimer [Lambda(6)Delta(3)Lambda-Ru(10)](20+)[PF(6)(-)](20) is shown to bind strongly and specifically to the SWNTs. Most of the nanotube's ends are functionalized with this large (5.8 nm), optically active, rigid supramolecular complex. We study the binding capacity with UV-vis and atomic absorption spectroscopy. Imaging the functionalized nanotubes with scanning electron microscopy and atomic force microscopy (AFM) yields direct confirmation of end functionalization. Statistical analysis of the AFM images shows the morphology of the functionalized ends is consistent with the nanotubes binding to one of the endo- or exoreceptors around the dendrimer. Implications of these results toward efficient nanomanufacturing of carbon nanotube devices are discussed.

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“…The very first example of a Type III-B rotaxane dendrimer was synthesized by Vögtle et al in 2001 through convergent synthesis. 86 They began with the evaluation of the divergent approach toward rotaxane dendrimer synthesis, but failed to proceed to G1.5 rotaxane dendrimers, and thus the convergent approach was then employed. The first step was to synthesize a phenolic hydroxy-protected macrocycle with diamine and stoppered by nucleophilic substitution with 5-(benzoyloxy)isophthaloyl dichloride.…”

Section: Type III Rotaxane Dendrimersmentioning

confidence: 99%