Cation-reinforced donor-acceptor pseudorotaxanes

Pascu, Sofia I.; Jarrosson, Thibaut; Naumann, Christoph; Otto, Sijbren; Kaiser, Guido; Sanders, Jeremy K. M.

doi:10.1039/b415418e

“…In each case, the complex lies on a crystallographic centre of inversion. The interplanar separation between the donor and acceptor rings lies in the range 3.21-3.62 A ˚, consistent with the interplanar separations of other pseudorotaxanes 19 and catenanes. 23, 25 The mean planes through the central unit of A and the naphthalene rings of the host are essentially parallel in each case, with a maximum deviation of 4.2 • found in the cation-free complex [1•A].…”

Section: Solid-state Structuressupporting

confidence: 78%

“…Li + and Na + . 18, 19 We also reported the role of naphthalene diimide acceptor molecule A in amplifying a mixed porphyrin-naphthylglycol macrocycle from a dynamic covalent disulfide library. 20 Prior to this, we had studied the donor-acceptor interactions between an electron-rich macrocycle (crown ether 1) and pyromellitic diimide (acceptor guest B).…”

Section: Introductionmentioning

confidence: 96%

Structures and solution dynamics of pseudorotaxanes mediated by alkali-metal cations

Pascu

¹

,

Naumann

²

,

Kaiser

³

et al. 2007

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Kinetic stability studies of a series of pseudorotaxanes formed from electron-rich crown ethers (hosts 1 and 2) and naphthalene diimide (guest A) in the presence of alkali salt templates MX (where M+ = Li+ and Na+, and X- = Cl-, Br-, I-, NO3- and CF3SO3-) were performed by 1H NMR. The switching between the (bound) host 1 and its linkage isomer host 2 (free) was monitored in solution in the presence and absence of alkali salts, to establish the relative thermodynamic stabilities in the series. We also report here six new crystal structures, for pseudorotaxanes of type: [1.A], [M2.1.A]2+ and [M2.2.A]2+. Their solution-phase structures are in good agreement with the solid-state structures determined by X-ray crystallography.

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“…In one example, Li + ions have been used to assist the formation of a unique donor-acceptor pseudorotaxane, [8] but it appears that Na + ions play a similar role in that system. [9] We became interested in forming pseudorotaxanes in solution with high efficiency and selectivity toward a single species of alkalimetal ion-especially if we could differentiate between the physiologically important, [10] but chemically similar, Na + and K + ions.[11] Herein, we report a new molecular recognition system based on the molecular cage 1 (Scheme 1) and two different threadlike molecules (anthraquinone and squaraine), each of which forms a pseudorotaxane complex with 1 in the presence of templating Na + ions and exhibits high selectively over the other alkali-metal ions tested. This ionspecific templating effect was easy to monitor because the complexation and decomplexation of the pseudorotaxane complexes in solution occurred with color changes that were detectable to the naked eye.…”

mentioning

confidence: 97%

Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

Hsueh

¹

,

Lai

²

,

Liu

³

et al. 2007

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The diverse range of binding geometries exhibited by metal ions and their relatively stable interactions with ligands can be exploited for the efficient template-directed synthesis of macrocycles,[1] supramolecular architectures, [2] and interlocked molecules.[3] Although the formation of rotaxanes or pseudorotaxanes has been demonstrated using transitionmetal ions coordinated to four (tetrahedral and square planar), [4] five (trigonal bipyramidal and square pyramidal), [5] and six (octahedral) [6] donor atoms, alkali-metal ions, which are useful templates for the synthesis of crown ethers, [7] are rarely used to direct the construction of such complexes. In one example, Li + ions have been used to assist the formation of a unique donor-acceptor pseudorotaxane, [8] but it appears that Na + ions play a similar role in that system. [9] We became interested in forming pseudorotaxanes in solution with high efficiency and selectivity toward a single species of alkalimetal ion-especially if we could differentiate between the physiologically important, [10] but chemically similar, Na + and K + ions.[11] Herein, we report a new molecular recognition system based on the molecular cage 1 (Scheme 1) and two different threadlike molecules (anthraquinone and squaraine), each of which forms a pseudorotaxane complex with 1 in the presence of templating Na + ions and exhibits high selectively over the other alkali-metal ions tested. This ionspecific templating effect was easy to monitor because the complexation and decomplexation of the pseudorotaxane complexes in solution occurred with color changes that were detectable to the naked eye. It appears from the solid-state structures that the dramatic Na Previously, we demonstrated that molecular cage 2 and anthraquinone (3, Scheme 2) can form pseudorotaxane-like complexes in solution when K + ions are present. [12] We suspected that greater ion-selective templating behavior would arise if we replaced the two openings resembling dibenzo [24]crown-8 (DB24C8) in 2 with two relatively smaller and more rigid units resembling dibenzo [18]crown-6

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“…Although the formation of rotaxanes or pseudorotaxanes has been demonstrated using transition‐metal ions coordinated to four (tetrahedral and square planar),4 five (trigonal bipyramidal and square pyramidal),5 and six (octahedral)6 donor atoms, alkali‐metal ions, which are useful templates for the synthesis of crown ethers,7 are rarely used to direct the construction of such complexes. In one example, Li + ions have been used to assist the formation of a unique donor–acceptor pseudorotaxane,8 but it appears that Na + ions play a similar role in that system 9. We became interested in forming pseudorotaxanes in solution with high efficiency and selectivity toward a single species of alkali‐metal ion—especially if we could differentiate between the physiologically important,10 but chemically similar, Na + and K + ions 11.…”

Section: Methodsmentioning

confidence: 99%

Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

Hsueh

¹

,

Lai

²

,

Liu

³

et al. 2007

View full text Add to dashboard Cite

The diverse range of binding geometries exhibited by metal ions and their relatively stable interactions with ligands can be exploited for the efficient template-directed synthesis of macrocycles,[1] supramolecular architectures, [2] and interlocked molecules.[3] Although the formation of rotaxanes or pseudorotaxanes has been demonstrated using transitionmetal ions coordinated to four (tetrahedral and square planar), [4] five (trigonal bipyramidal and square pyramidal), [5] and six (octahedral) [6] donor atoms, alkali-metal ions, which are useful templates for the synthesis of crown ethers, [7] are rarely used to direct the construction of such complexes. In one example, Li + ions have been used to assist the formation of a unique donor-acceptor pseudorotaxane, [8] but it appears that Na + ions play a similar role in that system. [9] We became interested in forming pseudorotaxanes in solution with high efficiency and selectivity toward a single species of alkalimetal ion-especially if we could differentiate between the physiologically important, [10] but chemically similar, Na + and K + ions.[11] Herein, we report a new molecular recognition system based on the molecular cage 1 (Scheme 1) and two different threadlike molecules (anthraquinone and squaraine), each of which forms a pseudorotaxane complex with 1 in the presence of templating Na + ions and exhibits high selectively over the other alkali-metal ions tested. This ionspecific templating effect was easy to monitor because the complexation and decomplexation of the pseudorotaxane complexes in solution occurred with color changes that were detectable to the naked eye. It appears from the solid-state structures that the dramatic Na Previously, we demonstrated that molecular cage 2 and anthraquinone (3, Scheme 2) can form pseudorotaxane-like complexes in solution when K + ions are present. [12] We suspected that greater ion-selective templating behavior would arise if we replaced the two openings resembling dibenzo [24]crown-8 (DB24C8) in 2 with two relatively smaller and more rigid units resembling dibenzo [18]crown-6

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Cation-reinforced donor-acceptor pseudorotaxanes

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Cited by 45 publications

References 65 publications

Structures and solution dynamics of pseudorotaxanes mediated by alkali-metal cations

Structures and solution dynamics of pseudorotaxanes mediated by alkali-metal cations

Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

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Cation-reinforced donor-acceptor pseudorotaxanes

Abstract: Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Cited by 45 publications

References 65 publications

Structures and solution dynamics of pseudorotaxanes mediated by alkali-metal cations

Structures and solution dynamics of pseudorotaxanes mediated by alkali-metal cations

Highly Selective Na+‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

Highly Selective Na+‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

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Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs

Highly Selective Na⁺‐Templated Formation of [2]Pseudorotaxanes Exhibiting Significant Optical Outputs