Dialkylammonium‐Ionen/Kronenether‐Komplexe: Vorläufer einer neuen Familie „mechanisch”︁ verknüpfter Moleküle

Ashton, Peter R.; Campbell, Paul J.; Chrystal, Ewan J. T.; Glink, Peter T.; Menzer, Stephan; Philp, Douglas; Spencer, Neil; Stoddart, J. Fraser; Tasker, Peter A.; Williams, David J.

doi:10.1002/ange.19951071711

Cited by 91 publications

(35 citation statements)

References 20 publications

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“…[35] Compound II was prepared as described elsewhere. [22] Gold nanocrystals, stabilized by chemisorbed I, were prepared following the method reported by Brust et al: [36] HAuCl 4 (0.155 g) in deionized H 2 O (15 mL) was added to a phase transfer catalyst nOct 4 NBr (1.101 g) in CDCl 3 (12 mL), and the resulting mixture stirred vigorously for approximately 10 min. The organic layer was recovered, the stabilizer (I, 0.070 g) in CDCl 3 (4 mL) and the reducing agent (NaBH 4 , 0.190 g) in H 2 O (13 mL) added, and the resulting mixture stirred overnight at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Heterosupramolecular Chemistry: Programmed Pseudorotaxane Assembly at the Surface of a Nanocrystal

Fitzmaurice

Rao

Preece

et al. 1999

Angew. Chem. Int. Ed.

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Section: Methodsmentioning

confidence: 99%

Heterosupramolecular Chemistry: Programmed Pseudorotaxane Assembly at the Surface of a Nanocrystal

Fitzmaurice

Rao

Preece

et al. 1999

Angew. Chem. Int. Ed.

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“…The search for novel protocols that can be utilized for the supramolecular synthesis [3] of new classes of pseudorotaxanes, by self-assembly, [4] has led us to develop [5] supramolecular systems that are based upon the mutual recognition between secondary dialkylammonium ions and macrocyclic polyethers of varying constitutions. We have demonstrated that the composition of the pseudorotaxane superarchitecture is dependent on the size of the macroring employed for the supramolecular synthesis (Figure 1): by way of illustration, only one NH 2 -containing strand can be passed through the cavity of the dibenzo [24]crown-8 (DB24C8) macroring, [5a, 5c±e, 5g] whereas two such strands can be fed through its larger congener bis-p-phenylene [34]crown-10 (BPP34C10), [5b±e] which acts, in this instance, as a ditopic coreceptor.…”

Section: Introductionmentioning

confidence: 99%

Doubly Docked Pseudorotaxanes

et al. 1998

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“…Of these self-assembling systems, secondary dialkylammonium ions (R 2 NH 2 + ) are well-known for their ability to thread through, for example, a dibenzo [24]crown-8 (DB24C8) ring to give a [2]pseudorotaxane, [5] owing to a combination of strong [ + N À H···O] hydrogen bonding and [CÀH···O] interactions. Upon deprotonation of the R 2 NH 2 + moiety, the two [ + NÀH···O] hydrogen bonds are eliminated, and the [2]pseudorotaxanes are dethreaded.…”

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confidence: 99%

Controlling Molecular Rotary Motion with a Self‐Complexing Lock

Feringa

2010

Angew Chem Int Ed

111

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Biological motors, such as the kinesin or myosin linear and ATPase rotary motor systems, [1] have been a source of inspiration for the development of a variety of artificial molecular mechanical devices [2] (including switches, shuttles, muscles, and rotors) and of elegant molecular motor systems.[3] Selfcomplexing and self-assembling systems [4] represent important dynamic compounds that play a prominent role in the field of molecular recognition and molecular devices. The uses of such supramolecular systems add attractive features to the construction of advanced nanoscale molecular machinery because of their potential to undergo controllable intramolecular complexation in response to a particular stimulus.Of these self-assembling systems, secondary dialkylammonium ions (R 2 NH 2 + ) are well-known for their ability to thread through, for example, a dibenzo [24] [6] have combined both the dibenzo[24]crown-8 and dialkylammonium ion structural motifs into a single system, most of these feature versatile intermolecular complexation rather than unique intramolecular self-complexation.Herein we report the design, characterization, and operation of a lockable [7] light-driven molecular rotary motor featuring a self-complexing [1]pseudorotaxane system. By taking advantage of the complexation between the R 2 NH 2 + and the DB24C8 units in the system, acid-basecontrolled threading-dethreading movements can be utilized to unlock or lock the molecular rotary motor. The design of the molecular system with a self-complexing lock is illustrated in Scheme 1. The molecular system cis-1-H·PF 6 is composed of 1) a second-generation light-driven molecular motor [8][9][10] based on an overcrowded alkene, in which the molecular rotor (2,6-dioxonaphthalene, upper half) rotates 3608 relative to the stator (xanthene, lower half) upon repetitive photochemical trans-cis isomerizations and subsequent thermal irreversible helix inversion steps, 2) a DB24C8 macrocyclic ring incorporated into the xanthene lower stator half, which can act as a socket for the dialkylammonium moiety, and 3) a R 2 NH 2 + moiety attached to the upper rotor half by a short spacer, which can insert itself as a plug into the DB24C8 macrocycle socket. The free OH group at the end of the arm can be easily functionalized to construct interlocked rotaxanes. cis-1-H·PF 6 was prepared in 20 steps (Schemes S1-S4 in the Supporting Information) and characterized by 1 H and 13 C NMR spectroscopy and high-resolution mass spectrometry. [11] The 1 H NMR spectrum (500 MHz, 298 K) of the hexafluorophosphate salt cis-1-H·PF 6 (Figure 1 a), recorded in [D 6 ]DMSO, has similar splitting patterns as the spectrum of the unprotonated cis-1 in CD 2 Cl 2 (Figure 1 b), [6a] which can be rationalized by attributing it to the uncomplexed species, that is, the dialkylammonium ion does not reside inside the DB24C8 cavity.[6c] A more complicated 1 H NMR spectrum of cis-1-H·PF 6 was obtained in CD 2 Cl 2 (Figure 1 c), as is evident in the region d = 3.5-4.4 ppm corresponding to the resonanc...

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Dialkylammonium‐Ionen/Kronenether‐Komplexe: Vorläufer einer neuen Familie „mechanisch”︁ verknüpfter Moleküle

Abstract: 90.67(2)", V = 1675 A3, 2 = 2, p,,.,. = 1.54 p(CuKJ = 21.4 em-', 4216 unabhangige Reflexe, 2411 davon beobachtetmit IF,I > 4u(~FJ). 28 <110",Verfeinerung zu R = 0.138, R, = 0.157. Siemens-P4/PC-Diffraktometer fur 3 ' 2PF6 und 4 4PF6 und Siemens-P4/

Cited by 91 publications

References 20 publications

Heterosupramolecular Chemistry: Programmed Pseudorotaxane Assembly at the Surface of a Nanocrystal

Heterosupramolecular Chemistry: Programmed Pseudorotaxane Assembly at the Surface of a Nanocrystal

Doubly Docked Pseudorotaxanes

Controlling Molecular Rotary Motion with a Self‐Complexing Lock

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