The influence of side-chains on the complexation of cations by crowns. synthesis and cu(ii) complexation of n,n'-diaryl-diaza-18-crown-6

Sonveaux, Etienne

doi:10.1016/s0040-4020(01)91109-3

Cited by 17 publications

(4 citation statements)

References 15 publications

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“…Next, the effect of fluorine on the stability of the complexes was estimated by measuring the cation binding constants for F-A15C5 and F 2 -A 2 18C6 and comparing them with the literature data for the corresponding fluorine-free ligands N-phenylaza-15crown-5 (H-A15C5) 15 and N,N¢-diphenyldiaza-18-crown-6 (H 2 -A 2 18C6). 16 Binding constants (b) determined from the results of UV spectrophotometric titrations are given in Table 2. The ligands F-A15C5 and F 2 -A 2 18C6 have identical UV spectra consisting of a strong band at l max = 252 nm with a weaker shoulder at 275-295 nm.…”

Section: Metal Cation Binding To F-a15c5 and F 2 -A 2 18c6 In Solutionmentioning

confidence: 99%

Lariat ethers with fluoroaryl side-arms: a study of CF⋯metal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers

et al. 2009

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New lariat ethers, N-(o-fluorophenyl)aza-15-crown-5 (F-A15C5) and N,N'-bis(o-fluorophenyl)diaza-18-crown-6 (F(2)-A(2)18C6), were prepared by the N-arylation of the corresponding azacrown ethers. The interaction of the ligands with metal cations was studied in solution by (1)H and (19)F NMR (in acetone-d(6)) and UV spectroscopy (MeOH) confirming the formation of complexes of F(2)-A(2)18C6 with K(+), Na(+), Ag(+), Ba(2+), Pb(2+) and of F-A15C5 with Na(+) and giving evidence of CFmetal cation interaction. Cation binding constants (beta, evaluated by UV titration method), demonstrate that F-A15C5 and F(2)-A(2)18C6 form more stable complexes than their fluorine-free analogs. The effect depends on the nature of the metal cation and is at a maximum for hard, singly charged cations (up to 3 logbeta units for K(+) complex of F(2)-A(2)18C6). The X-ray structures of complexes [Pb(F(2)-A(2)18C6)(H(2)O)](ClO(4))(2) () and [Ba(F(2)-A(2)18C6)(ClO(4))(2)] () reveal short Pb-F (2.805 A) and Ba-F (2.965 A) contacts. Complex is centrosymmetric (C(i)), while complex has C(2) symmetry with one-side coordination of o-fluorophenyl groups to Pb(2+). This "one-side" coordination mode of Pb(2+) is indicative of a partial localization of the Pb(2+) lone pair.

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Section: Metal Cation Binding To F-a15c5 and F 2 -A 2 18c6 In Solutionmentioning

confidence: 99%

Lariat ethers with fluoroaryl side-arms: a study of CF⋯metal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers

et al. 2009

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“…The proton-ionizable crown ethers with side arms that have been synthesized thus far have utilized largely carboxylic acid units (e.g., XXIU-XXVI) [12,22,23,26,28,30,33,36,38,40,[43][44][45][46][47][48]50,53,55,58,60], phenolic OH groups (~, LXXIV-LXXXIU) [31,35,39,42,56,57,65,66] or amine nitrogens (~, X-XVIII) [25,31,32,34,52,54,65] to provide the acidic proton. A few have been synthesized with phosphonic acid functions (~, XLV~L) [24,36,51,59,61,62] and others have a sulfonic acid group (XXI,XLIV) [36,61].…”

Section: Ionizable Pendant Groupsmentioning

confidence: 99%

“…In an interesting study using crowns CLXVllI·CLXXV with two ionizable side arms attached at the nitrogen atoms of a diazacrown, Sonveaux [52] suggested that a Cu(II) ion is able to complex in two different locations in the cavity, depending on whether one or two of the charged side arms are involved in coordination with the metal. If only one side arm is ionized, the Cu(II) ion coordinates close to the nitrogen atom on the same side of the cavity as the ionized side arm, thus being complexed off-center in the cavity.…”

mentioning

confidence: 99%

Ion Extraction and Transport by Proton-Ionizable Crown Ethers

Brown¹,

Bartsch²

1991

Inclusion Aspects of Membrane Chemistry

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“…In the case of azacrown ethers, this opens up virtually unlimited possibilities for varying the coordination properties of the macrocyclic ligand, which enables one to perform its "fine tuning," thus achieving selectivity with respect to a par ticular cation or a group of metal cations. 1,3- 14 The chemi cal nature and conformational flexibility of pendant groups are of particular importance for selective binding of hard lanthanide(III) and actinide cations. 5,10,15- 17 We prepared the bis N (β acylvinyl) derivative of diaza 18 crown 6 ether by direct acylvinylation of the latter (S N V type re action 18 ).…”

mentioning

confidence: 99%

N,N’-Bis(acylvinylated) diaza-18-crown-6 ether as a lanthanide-selective macrocyclic complex-forming agent

et al. 2005

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Nucleophilic substitution in β chlorovinyl phenyl ketone with diaza 18 crown 6 ether resulting in displacement of the chlorine atom afforded N,N´ bis(3 oxo 3 phenylpropen 1 yl) 1,10 diaza 18 crown 6 ether. The ability of the latter to form complexes with a number of metal cations was studied. However, the complex formation occurs only with the rare earth cations Ln 3+ and Th 4+ . This fact was demonstrated by UV and 1 H NMR spectroscopy of solutions, confirmed by isolations of glassy phases of composition L 3 M 2 (NO 3 ) 6 •nH 2 O (M = La, Y, n ≈ 4-7), and supported by IR spectra of these phases in KBr pellets. The formation of complexes with La 3+ and Y 3+ leads to an increase in fluorescence intensity of the ligand. The stability constants of the 1 : 1 complexes in methanol were evaluated by spectro photometry. These constants increase with decreasing ionic radius of the cation.

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The influence of side-chains on the complexation of cations by crowns. synthesis and cu(ii) complexation of n,n'-diaryl-diaza-18-crown-6

Cited by 17 publications

References 15 publications

Lariat ethers with fluoroaryl side-arms: a study of CF⋯metal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers

Lariat ethers with fluoroaryl side-arms: a study of CF⋯metal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers

Ion Extraction and Transport by Proton-Ionizable Crown Ethers

N,N’-Bis(acylvinylated) diaza-18-crown-6 ether as a lanthanide-selective macrocyclic complex-forming agent

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