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Marcos, Paula M.; Ascenso, José R.; Segurado, Manuel A. P.; Pereira, J. L. C.

doi:10.1023/a:1016083624362

Cited by 55 publications

(27 citation statements)

References 31 publications

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“…Compound 1b also displays the highest Pb 2 þ /Zn 2 þ selectivity (S ¼ 5.3, 2.4 and 3.5 for derivatives 1b, 2b and 3b, respectively). As we have previously observed, triamide 1b, like other derivatives containing hard oxygen donor atoms [25,26], shows a clear preference for soft and of intermediate nature Lewis acids.…”

Section: Extraction Studiessupporting

confidence: 75%

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Binding Properties and Molecular Mechanics Calculations ofp-tert-Butylhexahomotrioxacalix[3]arene Tri(diethyl)amide with Alkali, Alkaline Earth, Transition and Heavy Metal Cations

Marcos

Ascenso²,

Cragg³

2007

Supramolecular Chemistry

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The binding of alkali, alkaline earth, transition (Mn 2 1 , Fe 2 1 , Co 2 1 , Ni 2 1 , Cu 2 1 and Zn 2 1 ) and heavy metal (Ag 1 , Cd 2 1 , Hg 2 1 and Pb 2 1 ) cations by cone p-tertbutylhexahomotrioxacalix[3]arene tri(diethyl)amide (1b) has been assessed by extraction studies of metal picrates from water to dichloromethane and proton NMR titration experiments. Molecular modelling techniques were also employed to complement the NMR data. The results are compared to those obtained with the dihomooxacalix[4]arene (2b) and calix[4]arene (3b) derivative analogues. Triamide 1b displays a high extracting ability towards Na 1 , Ba 2 1 , Ni 2 1 , Co 2 1 , Ag 1 and mainly Pb 2 1 (80% E). However, these values are lower than those obtained with tetraamides 2b and 3b, presumably due to the higher conformational flexibility of 1b. 1 H NMR titrations indicate the formation of 1:1 complexes between 1b and all the cations studied, and also that they should be located inside the cavity defined by the phenoxy and carbonyl oxygen atoms.

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Section: Extraction Studiessupporting

confidence: 75%

“…Blank experiments showed negligible picrate extraction in the absence of a calixarene. The details of metal picrate preparation have already been described [25,39].…”

Section: Extraction Studiesmentioning

confidence: 99%

Binding Properties and Molecular Mechanics Calculations ofp-tert-Butylhexahomotrioxacalix[3]arene Tri(diethyl)amide with Alkali, Alkaline Earth, Transition and Heavy Metal Cations

Marcos

Ascenso²,

Cragg³

2007

Supramolecular Chemistry

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“…Many studies have focused on their binding ability toward metal ions, predominantly alkali and alkaline-earth but also transition and heavy metal cations. [3][4][5][6][7][8][9][10][11] As experimentally proved, coordination of a metal ion to the groups (say carbonyls) at the lower rim exerts a conformation change on the whole calixarene unit, which usually adopts a more cone-like form changing thus subtly its host properties for a guest molecule. The actual conformation change appears to be strongly dependent on the nature of the ion as well as the calixarene itself.…”

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confidence: 99%

A Proton Complex of p-tert-Butylcalix[4]arene-tetrakis(N,N-dimethylthioacetamide): NMR Evidence and Probable Structure

Křı́ž

Dybal

Makrlík

et al. 2007

Supramolecular Chemistry

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Using 1 H and 13 C NMR together with density functional theoretical (DFT) calculations, we show that p-tert-butylcalix[4]arene-tetrakis(N,N-dimethylthioacetamide) (1) forms a stable equimolecular complex with proton in the form of hydroxonium ion in nitrobenzene-d 5. Protons were offered by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) and converted to hydroxonium ions by traces of water. The complex 1. H 3 O + adopts a slightly asymmetric but rapidly motionally averaged conformation, which is distinctly more cone-like than ligand 1. The hydroxonium ion H 3 O + is bound partly to thiocarbonyl sulphur atoms and partly to phenoxy oxygen atoms of 1 by strong hydrogen bonds and other electrostatic interactions.

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“…Calixarenes find applications as selective binders and carriers, as analytical sensors, as catalysts and model structures for biomimetic studies [1,2], and finally, as efficient and selective extractants for nuclear waste treatment [3,4]. In the field of host-guest chemistry, many studies have focused on the binding ability of calixarene derivatives with carbonyl groups at their lower rims towards metal ions, predominantly alkali and alkaline-earth [5][6][7], but also transition and heavy metal cations [8][9][10][11][12][13][14][15][16][17][18][19][20], and even towards H 3 O + [21][22][23] Recently, the stability constants of some univalent and divalent metal cationic complexes with hexaethyl p-tert-butylcalix [6]arene hexaacetate, called also cesium ionophore II (abbrev. 1; see Scheme 1), in nitrobenzene saturated with water have been reported [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Cesium ionophore II as an extraordinarily effective macrocyclic receptor for the barium cation

Makrlík

Böhm

Vaňura

2015

Journal of Molecular Structure

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Untitled

Cited by 55 publications

References 31 publications

Binding Properties and Molecular Mechanics Calculations ofp-tert-Butylhexahomotrioxacalix[3]arene Tri(diethyl)amide with Alkali, Alkaline Earth, Transition and Heavy Metal Cations

Binding Properties and Molecular Mechanics Calculations ofp-tert-Butylhexahomotrioxacalix[3]arene Tri(diethyl)amide with Alkali, Alkaline Earth, Transition and Heavy Metal Cations

A Proton Complex of p-tert-Butylcalix[4]arene-tetrakis(N,N-dimethylthioacetamide): NMR Evidence and Probable Structure

Cesium ionophore II as an extraordinarily effective macrocyclic receptor for the barium cation

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