Synthesis of a rhenium complex appending a cyclodextrin unit on a ligand

Nakamura, Asao; Okutsu, Satoshi; Oda, Yuji; Ueno, Akihiko; Toda, Fujio

doi:10.1016/0040-4039(94)85371-1

Cited by 16 publications

(5 citation statements)

References 16 publications

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“…From the emission data presented therefore, k is estimated to be 7.0 ± 0.4 × 10 7 s −1 and 1.3 ± 0.1 × 10 8 s −1 for [([Re(bpy)(CO) 3 (CD-4Py)]) 2 C 60 ] 2+ and [([Ru(bpy) 2 (CD-2Py)]) 2 C 60 ] 4+ , respectively. These moderately fast processes are consistent with the large driving forces estimated above and are similar to the rate observed by Nakamura et al 28 for electron transfer from a rhenium CD complex to a guest N,N-diethylaniline where k et was estimated to be 3.7 × 10 7 s −1 . Significantly, the large rates observed indicate efficient excited state communication between the metal centres and the encapsulated fullerene across the cyclodextrin bridge.…”

Section: Photophysical Propertiessupporting

confidence: 90%

Fullerene bridged metallocyclodextrin donor–acceptor complexes: optical spectroscopy and photophysics

McNally

Forster

Russell³

et al. 2006

Dalton Trans.

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Two pyridine substituted beta-cyclodextrins have been synthesized and coordinated to the photoactive metal centres, [Ru(II)(bpy)2] and [Re(I)(CO)3bpy], where bpy is 2,2'-bipyridyl. The photophysical and electrochemical properties of these model complexes have been examined and compared with dinuclear complexes formed when C60 was included between two cyclodextrin cavities of the metallocyclodextrin units. On inclusion of C60, significant quenching of the emission of the luminophores is observed. Concentration and laser power dependence confirm that this quenching is intramolecular. The quenching process is interpreted in terms of a photoinduced electron transfer between the photosensitizer and C60 centre on the basis of spectroscopic and electrochemical evidence. Rate constants of 1.3 +/- 0.1 x 10(8) and 7.0 +/- 0.4 x 10(7) s(-1) have been determined for the Ru and Re based complexes, respectively. Significantly, these large rate constants indicate that that there is substantial electronic communication across the cyclodextrin at least for excited state processes.

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Section: Photophysical Propertiessupporting

confidence: 90%

Fullerene bridged metallocyclodextrin donor–acceptor complexes: optical spectroscopy and photophysics

McNally

Forster

Russell³

et al. 2006

Dalton Trans.

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“…Sensing Properties of the [Cu(CD-dien-DNS)] Complex. The metal complexes of ligand-appended cyclodextrins can be used as luminescent chemosensors for organic molecules, provided that the addition of the analytes induces a large modification of the photophysical properties of either the ligand or the metal ion, as recently reported in several examples. , …”

Section: Resultsmentioning

confidence: 88%

Fluorescent Chemosensor for Organic Guests and Copper(II) Ion Based on Dansyldiethylenetriamine-Modified β-Cyclodextrin

et al. 1997

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A modified cyclodextrin containing a dansyldiethylenetriamine metal-binding group (6-deoxy-6-N-(N‘‘-dansyldiethylenetriamino)-β-cyclodextrin, CD-dien-DNS) was synthesized. The conformation of CD-dien-DNS was studied by 2D NMR (ROESY spectra) in D2O, by circular dichroism, and by fluorescence. The results were compared with those previously obtained with the analogous 6-deoxy-6-N-(N‘-dansylethylenediamino)-β-cyclodextrin (CD-en-DNS) and were consistent with the self-inclusion of the dansyl group within the macrocycle cavity. However, the orientation of the dansyl group for CD-dien-DNS was found to be equatorial, whereas for CD-en-DNS it was axial, suggesting a dependence of the orientation of the dansyl group upon the length of the linker. In the presence of lipophilic organic molecules, CD-dien-DNS showed sensing properties similar to those observed for CD-en-DNS, suggesting a similar “in-out” movement of the dansyl group, due to competitive inclusion of the guest. Unlike CD-en-DNS, CD-dien-DNS was found to be a fluorescent chemosensor for copper(II) ion, with a linear response up to a 1:1 molar ratio, suggesting that a more flexible conformation of the linker and the presence of additional binding sites allow binding of the metal ion by the amino and sulfonamidate groups. Good selectivity for Cu(II), when compared with Fe(II), Co(II), Ni(II), and Zn(II), was observed. The CD-dien-DNS copper(II) complex was shown to behave as a chemosensor for bifunctional molecules, such as amino acids. In fact, upon addition of alanine, tryptophan, and thyroxine, the negligible fluorescence intensity of Cu(CD-dien-DNS) complex was “switched on”, with a response dependent on the amino acid side chain.

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“…Most of these cases are united in their use of a cyclodextrin derivative as the receptor component in aqueous media. Nakamura's recent example 193 is pictured as a representative of this appealing line of research. Compound 193 also acts as a convenient bridge with the foregoing paragraphs since metal complexation and hydrophobic binding potential are coexistent within it.…”

Section: B “On−off” Switches Using Redox-active Guestsmentioning

confidence: 99%

“…Most of these cases are united in their use of a cyclodextrin derivative as the receptor component in aqueous media. Nakamura's recent example 193 589 is pictured as a representative of this appealing line of research.…”

Section: B "On−off" Switches Using Redox-active Guestsmentioning

confidence: 99%

“…Interestingly, a closely related supermolecule was reported a year earlier but the stated aim of guest effects on photoproperties remain unrealized. 593 Compound 194 594 is similar to 193 589 as it shows both static and dynamic fluorescence quenching with electron-rich guest such as anthracene-2sulfonate. The regioisomer of 194 where the fluorophore is attached to the wider rim via its secondary alcohol moieties shows weaker binding and quenching.…”

Section: B "On−off" Switches Using Redox-active Guestsmentioning

confidence: 99%

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