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Antonov, L.; Vladimirova, M. P.; Stanoeva, Elena; Fabian, Walter M. F.; Ballester, Loreto; Mitewa, M.

doi:10.1023/a:1011190403722

Cited by 14 publications

(7 citation statements)

References 16 publications

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“…This approach has Table 3 Binding constants (log K) for complexation of metal cations with 1a and 2a in acetonitrile, along with ranges reported for various related aza-15-crown-5-ether dyes in acetonitrile 3.16 ± 0.24 2.80 ± 0.06 1.9-3.6 been adopted successfully in reported semiempirical and DFT calculations. [36][37][38] The calculated structures of ML1a and ML2a show that the ligands are remarkably planar between the two nitrogen atoms, which is consistent with observed X-ray crystallographic structures of similar systems 15 and indicates that there is strong conjugation throughout the pyridyl and aryl ring systems and the alkenyl or alkynyl spacers. 7 Selected bond lengths given in Fig.…”

Section: Cation Binding Constantssupporting

confidence: 79%

Cation sensors containing a (bpy)Re(CO)3 group linked to an azacrown ether via an alkenyl or alkynyl spacer: synthesis, characterisation, and complexation with metal cations in solution

Lewis

Moore

2004

Dalton Trans.

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Two [(bpy)Re(CO)3L]+ complexes (bpy = 2,2'-bipyridine), where L contains an aza-15-crown-5 ether which is linked to Re via an alkenyl- or alkynyl-pyridine spacer, have been synthesised along with model complexes. Solutions of the complexes in acetonitrile have been studied by UV-Vis absorption spectroscopy, and by 1D and 2D 1H NMR spectroscopy. Strong UV-Vis bands, assigned to intraligand charge-transfer transitions localised at the L ligands, blue shift on protonation of the azacrown nitrogen atom or on complexation of alkali-metal (Li+, Na+ and K+) or alkaline-earth metal (Mg2+, Ca2+ and Ba2+) cations to the azacrown; the magnitude of the blue shift is dependent on the cation, with protonation giving the largest shift of ca. 100 nm. Cation binding constants in the range of log K= 1-4 depend strongly on the identity of the metal cation. Protonation or cation complexation causes downfield shifts in the 1H NMR resonances from most of the azacrown and L ligand protons, and their magnitudes correlate with those of the blue shifts in the UV-Vis bands; shifts in the azacrown 1H NMR resonances report on how the different metal cations interact with the macrocycle. UV-Vis and 1H NMR spectra of the free L ligands enable the effect of the Re centre to be assessed. Together, the data indicate that the alkene spacer gives a more responsive sensor than the alkyne spacer by providing stronger electronic communication across the L ligand.

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Section: Cation Binding Constantssupporting

confidence: 79%

Cation sensors containing a (bpy)Re(CO)3 group linked to an azacrown ether via an alkenyl or alkynyl spacer: synthesis, characterisation, and complexation with metal cations in solution

Lewis

Moore

2004

Dalton Trans.

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“…Although it is given as essentially planar by the crystallographic data, 31 the quantum chemical calculations, depending on the level of theory, are in this case quite contradictory. 13,27,33 At the same time the decrease in the 2PA intensity is not so remarkable in comparison with AN=ND and AC=CD.…”

Section: Resultsmentioning

confidence: 86%

A systematic femtosecond study on the two-photon absorbing D-π-A molecules–π-bridge nitrogen insertion and strength of the donor and acceptor groups

Antonov

Kamada

Ohta

et al. 2003

Phys. Chem. Chem. Phys.

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129

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“…As seen, the 44 where the macrocycle is conjugated to the chromophore system. At the same time, the differences in the stability constants in 3 in respect of the cation are not as profound as in 4 ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

Tautocrowns: a concept for a sensing molecule with an active side-arm

et al. 2010

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A new sensing molecule containing aza-15-crown-5 as a receptor and 4-(phenyldiazenyl)naphthalen-1-ol as a signal converter has been synthesized. In the free ligand, the hydrogen bonding between the tautomeric OH group and the nitrogen atom from the macrocycle fully shifts the tautomeric equilibrium towards the enol form. The complexation reverses the equilibrium as a result of the strong interaction between the metal ion captured in the macrocyclic moiety and the tautomeric carbonyl group. The complex formation is accompanied by strong bathochromic (between 60 and 100 nm) and hyperchromic effects on the absorption spectra. Obviously, the tautomeric OH/C]O groups play the role of an active side-arm in the complexation, supporting it via formation of a 3D cavity and giving possibility for ejection of the guest compound under stimuli to shift the tautomeric process back.

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Untitled

Cited by 14 publications

References 16 publications

Cation sensors containing a (bpy)Re(CO)3 group linked to an azacrown ether via an alkenyl or alkynyl spacer: synthesis, characterisation, and complexation with metal cations in solution

Cation sensors containing a (bpy)Re(CO)3 group linked to an azacrown ether via an alkenyl or alkynyl spacer: synthesis, characterisation, and complexation with metal cations in solution

A systematic femtosecond study on the two-photon absorbing D-π-A molecules–π-bridge nitrogen insertion and strength of the donor and acceptor groups

Tautocrowns: a concept for a sensing molecule with an active side-arm

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