The Spatial Demand of Dendrimers: Deslipping of Rotaxanes

Hübner, Gosia M.; Nachtsheim, G.; Li, Qian Yi; Seel, Christian; Vögtle, Fritz

doi:10.1002/(sici)1521-3773(20000403)39:7<1269::aid-anie1269>3.0.co;2-w

Cited by 51 publications

(27 citation statements)

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“…280 The dendritic rotaxanes were prepared by Williamson ether coupling reaction between a bulky alkoxide and a dendritic bromide. Dethreading rates and computer modeling suggested that the steric requirements of the second generation dendron exceeded those of a trityl group, whereas the third generation appeared to be larger than the tert-butyl trityl group.…”

Section: Environmentally Responsive Cores: Dendritic Probesmentioning

confidence: 99%

Convergent Dendrons and Dendrimers: from Synthesis to Applications

2001

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I. Introduction 3819 A. Structure 3820 B. Applications 3821 C. Synthetic Approaches 3821 1. Divergent Approach 3821 2. Convergent Approach 3822 D. Features of the Convergent Synthesis 3823 1. Structural Purity 3823 2. Synthetic Versatility 3823 II. Convergent Synthesis of Dendrons and Dendrimers 3824 A. Single-Stage Convergent Syntheses 3824 1. Poly(aryl ether) Dendrimers 3824 2. Poly(aryl alkyne) Dendrimers 3826 3. Poly(phenylene) Dendrimers 3827 4. Poly(alkyl ester) Dendrimers 3827 5. Poly(aryl alkene) Dendrimers 3828 6. Poly(alkyl ether) Dendrimers 3828 7. Other Convergent Dendrimer Syntheses 3829 B. Accelerated Approaches 3829 1.

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Section: Environmentally Responsive Cores: Dendritic Probesmentioning

confidence: 99%

Convergent Dendrons and Dendrimers: from Synthesis to Applications

2001

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“…In these cases the steric size of the stoppers is not the only parameter to have in mind. Subtle variations on the structure of the thread (flexibility, length, functional groups orientation) or macrocycle (void size) drastically effects on the energy necessary to break the mechanical bond. The paradigmatic example reported by Schalley nicely illustrates how a minimal hydrogen‐deuterium exchange at the stoppers can notably affect to the kinetic stabilization of interlocked species …”

Section: Introductionmentioning

confidence: 99%

Thermally and Photochemically Induced Dethreading of Fumaramide‐Based Kinetically Stable Pseudo[2]rotaxanes

et al. 2019

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The thermally and photochemically induced dethreading of a series of pseudo[2]rotaxanes bearing tetraalkyl‐substituted fumaramide axles and polyamide macrocycles is reported herein. The length of the alkyl chains at the ends of the thread, the void size, and flexibility of the macrocycle and the intercomponent interactions are critical for a satisfactory dethreading process. 1H NMR kinetic experiments were carried out in order to calculate the rate constants of the thermal dethreading processes and stabilities of the rotaxanes, by comparing with the similar data for the deslipping of the succinamide surrogates. The deslipping reaction occurs faster with the fumaramide systems than succinamide ones. The incorporation of adamantane moieties into the polyamide macrocycle drastically slowed down the disconnecting process. Furthermore, interlocked systems with dipropylamino groups as stoppers experienced a rapid dethreading when irradiated under UV‐light, a process triggered by the fumaramide–maleamide isomerization. In this case, the n‐propyl groups are not bulky enough to keep together both components as the number of hydrogen bonds between thread and macrocycle is halved in the maleamide systems.

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“…Fréchet's dendrons had been employed as stoppers for the preparation of [36]. The spatial sizes of the various dendritic fragments were also determined by means of a deslipping experiment.…”

Section: Dendritic Oligoethers Based On a 35-dihydroxybenzyloxy Repementioning

confidence: 99%