Ein [2]‐Catenan auf Bestellung

Ashton, Peter R.; Goodnow, Timothy T.; Kaifer, Ángel E.; Reddington, Mark V.; Slawin, Alexandra M. Z.; Spencer, Neil; Stoddart, J. Fraser; Vicent, Cristina; Williams, David J.

doi:10.1002/ange.19891011023

Cited by 151 publications

(53 citation statements)

References 25 publications

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“…[13] However, as observed for related interlocked molecules containing electroactive subunits, pyromellitimide [2]catenane 9 and its naphthalene analogue 11 both exhibit a splitting of the first reduction followed by a further two-electron reduction process. Figure 2 shows the CV trace for [2]catenane 9.…”

Section: Electrochemistrymentioning

confidence: 92%

Photophysical and Electrochemical Characterisation of the Interactions between Components in Neutral π-Associated [2]Catenanes

et al. 2000

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The electrochemical and photophysical properties of a variety of neutral pi-associated [2]catenanes have been explored by using cyclic voltammetry, absorption and luminescence spectrophotometry and the measurement of exited-state lifetimes. Several trends that could be correlated with interactions between the mechanically linked components of the structures were revealed from comparative study of catenane precursors, model compounds and the [2]catenanes themselves. Throughout, emphasis is placed on pair-wise comparisons between systems which differ in a single structural feature. Substitution in a catenane of a pyromellitic diimide unit by a naphthalene diimide yields more readily reduced derivatives, whose absorption spectra reveal charge transfer within the catenane to be a lower energy process of reduced intensity. Conversion of the butadiyne links within the diimide macrocycle of the catenanes to saturated chains results in an increase in both the energy and intensity of their charge-transfer bands; electrochemically these derivatives are all harder to reduce than the parent systems. Replacement of one of the electron-donating components of the catenanes with a less effective aromatic donor bearing a carboxy group also decreases the energy and intensity of the charge-transfer feature and is accompanied by a slightly more ready reduction. A sequence of reduction and translational events is proposed to explain the intriguing electrochemical behaviour of a catenane that contains one pyromellitic and one naphthalene diimide. For some systems the photophysical and electrochemical techniques, whilst exploring distinct physical phenomena, are shown to be in good agreement by comparison of shifts of electrochemical reduction waves with those of charge-transfer absorption features.

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Section: Electrochemistrymentioning

confidence: 92%

Photophysical and Electrochemical Characterisation of the Interactions between Components in Neutral π-Associated [2]Catenanes

et al. 2000

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“…The interactions between p-electron acceptors (e.g., the paraquat dication [5] ) and p-electron donors (e.g., the hydroquinone unit [6] ) have provided the inspiration for the synthesis of a wide range of mechanically interlocked structures. [7] It may be recalled that the [2]catenane 4 4 , comprised of bis-pphenylene-34-crown-10 (BPP34C10) and cyclobis(paraquatp-phenylene), is formed in a remarkable 70 % yield [8] at ambient pressure in MeCN (Scheme 1), where 3 acts as a template for the reaction of 2 with 1 4 . The efficiency of this catenation is, in part, a result of the high level of preorganiza- tion present in the macrocyclic polyether.…”

Section: Introductionmentioning

confidence: 99%

The Synthesis and Spectroscopic Properties of Macrocyclic Polyethers Containing Two Different Aromatic Moieties and Their [2]Catenanes Incorporating Cyclobis(paraquat-p-phenylene)

Ballardini¹,

Balzani²,

Gandolfi³

et al. 1998

Chem. Eur. J.

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The synthesis of six derivatives of bis-p-phenylene-34-crown-10 (BPP34C10) in which one or both of the p-phenylene rings are replaced by other p-electron-rich aromatic ring systems, and their subsequent use as templates for the self-assembly of the tetracationic cyclophane cyclobis(paraquatp-phenylene) and thus the construction of [2]catenanes, are described. The pphenylene rings in BPP34C10 have been replaced variously by p-xylyl units, 1,5-, 1,6-, 2,6-and 2,7-naphtho units, and a naphthalene-2,6-dimethylyl ring system in the six new crown ether derivatives. Five of the [2]catenanes have the potential to exist in solution as equilibrating mixtures of two translational isomers, the proportions of which have been determined in solution by dynamic 1 H NMR spectroscopy. The absorption spectra and luminescence properties (fluorescence, phosphorescence, and excitation spectra, excitation state lifetimes, and fluorescence quantum yields) of the BPP34C10 derivatives (in which one of the p-phenylene rings has been replaced by either a p-xylyl unit or a naphthalene-2,6-dimethylyl unit or where both of the p-phenylene rings have been replaced, one by a p-xylyl unit and the other by a 1,5-naphtho unit) and their derived [2]catenanes, with cyclobis(paraquat-p-phenylene) as the interlocking cyclophane component, have been investigated. Comparison with the properties of simple model compounds shows the presence of intra-and intermolecular electronic interactions between the component units of the crown ethers and catenanes. The main consequences of these interactions in the crown ethers are small perturbations in the absorption spectra of the two chromophoric units, and strong changes in the luminescence properties due to the occurrence of intercomponent energytransfer processes and charge-transfer (CT) interactions. In the [2]catenanes, perturbations in the absorption spectra of the component units of the crown ether and tetracationic cyclophane, accompanied by the appearance of CT absorption bands in the visible region, and complete luminescence quenching caused by the presence of low-energy CT levels are observed.

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“…[1][2][3] Due to their unique ability to complex particularly alkali and alkaline earth metal ions, they find wide applications in many fields of synthetic, analytical, and physical organic chemistry. 4 Although molecular recognition is now verified by highly diversified and tailor-made structural component, [5][6] simple crown compounds are still attractive, for instance due to their generally good solubility in many solvents. The remarkably easy formation of large crown ether rings from noncyclic precursors using metal There are number of reports, which suggest that in the case of condensation between dihydroxy aromatics and activated polyethylene glycols, the nature of the template influences the size and extent to the rate of macrocyclization.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of new aza- and thia-crown ethers and their metal ion templates synthesis as model case study

Kamali¹,

Shockravi²,

Mohtasham³

et al. 2014

Arkivoc

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Four new thia-and four new aza-crown ethers were synthesized using the reaction of ethylene glycols ditosylated with 1,1´-(2,2´-dihydroxynaphthyl)sulfide (DNS) and 2,6-bis(3-hydroxyphenyl)-4-phenylpyridine in acetonitrile as solvent in the presence of bases (LiOH, NaOH, KOH and Cs 2 CO 3 ). In the synthesis of macrocycles based on DNS, the template effects of alkaline metal ions; Li + , Na + , K + and Cs + on the reaction yields were investigated. Sodium template generally was more effective for the synthesis of all four macrocycles. Relatively, good yields of 15-and 18-membered macrocycles were obtained in the presence of all kinds of applied cations. K + Cation was more effective template ion than Na + in the formation of 18-membered macrocycles due to their larger cavity size compared to the 15-membered cycles. The structures of macrocycles were confirmed by CHN/O analysis, IR, 1 H NMR, 13C NMR and mass spectrometry.

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Ein [2]‐Catenan auf Bestellung

Cited by 151 publications

References 25 publications

Photophysical and Electrochemical Characterisation of the Interactions between Components in Neutral π-Associated [2]Catenanes

Photophysical and Electrochemical Characterisation of the Interactions between Components in Neutral π-Associated [2]Catenanes

The Synthesis and Spectroscopic Properties of Macrocyclic Polyethers Containing Two Different Aromatic Moieties and Their [2]Catenanes Incorporating Cyclobis(paraquat-p-phenylene)

Synthesis of new aza- and thia-crown ethers and their metal ion templates synthesis as model case study

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