Using a large calixarene as a polyalkoxide ligand: tert-butylcalix[12]arene and its complex with the uranyl cation

Leverd, Pascal C.; Dumazet‐Bonnamour, Isabelle; Lamartine, R.; Nierlich, Martine

doi:10.1039/b000909l

Cited by 32 publications

(34 citation statements)

References 9 publications

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“…In fact, the calculated energy of the (δ u ) 2 (φ u ) 1 configuration is also close to that of (δ u ) 2 (σ g ). 1 Compared to U, the larger nuclear charge in Np stabilizes the f orbitals so that the δ u and φ u orbitals lie below the σ g level.…”

Section: Resultsmentioning

confidence: 99%

Actinyls in Expanded Porphyrin: A Relativistic Density-Functional Study

2004

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Actinyls AnO 2 with An ) U, Np, and Pu in an expanded porphyrin, alaskaphyrin (AP), are studied by a relativistic density-functional method. The electronic structures of both AnO 2 and AnO 2 AP are investigated by considering all possible low-lying states. To examine the importance of relativity, nonrelativistic calculations were also performed. For UO 2 and NpO 2 , the ground state is altered by the relativistic effects, but it remains unchanged for PuO 2 . The nonrelativistic ground states of the AnO 2 AP complexes are all high spin, where the AP highest occupied molecular orbital, b 2g , is singly occupied. At the relativistic level, there are two electrons in b 2g . The bonding characteristics in AnO 2 AP are examined by calculations of the AnO 2 -AP binding energy and charge distribution on AnO 2 . Other properties such as ionization potentials and electron affinities are also calculated. The predicted spectroscopic constants for NpO 2 , PuO 2 , NpO 2 AP, and PuO 2 AP would aid in future spectroscopic studies of these molecules.

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Section: Resultsmentioning

confidence: 99%

Actinyls in Expanded Porphyrin: A Relativistic Density-Functional Study

2004

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“…Their ability to ''host'' different inorganic and organic ionic or neutral species from solutions, solids and gases, introduced them among the most investigated versatile organic tools. The sulfonic, hydroxamic and carboxylic functional groups that substitute, either the hydrogen from the phenolic nuclei or the phenolic hydroxyls, determines their selectivity towards uranium increasing [50][51][52][53][54][55]. The present contribution aims to point out the uranyl sorption efficiency of the p-hexasulfonic calyx [6]arenic acid from a synthetic solution.…”

Section: Introductionmentioning

confidence: 99%

Removal of uranyl ions by p-hexasulfonated calyx[6]arene acid

Popescu

Filip²,

Humelnicu

et al. 2014

Journal of Nuclear Materials

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“…Crystal structures of calix [8]arenes (or of larger calixarenes [9][10][11][12] or their derivatives are rare, and to our knowledge no structure has been described yet for 1a, for which crystals were obtained by slow evaporation of a solution in CHCl 3 -pyridine ( Figure 2). The calix [8]arene molecule 1a adopts a centrosymmetrical conformation which can be characterized by four pairs of torsion angles around the Ar-CH 2 bonds 13 ( Table 1).…”

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confidence: 98%

Extended Calix[8]arenes by Sonogashira Cross-Coupling with Ethynylarenes

Böhmer¹,

Brusko²

2002

Synthesis

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Octabromo and -iodo derivatives of calix [8]arene were prepared in 85% and 73% yields and structurally confirmed by NMR, MS and IR spectroscopy and by the formation of ether or ester derivatives. The octaiodocalix [8]arene was successfully used in Sonogashira cross-coupling reactions for the preparation of p-arylethynylcalix[8]arenes. A single crystal X-ray structure of the starting calix[8]arene 1a shows the molecule in a centrosymmetric conformation, where four of the six pyridine solvent molecules are H-bonded to the hydroxyl groups.Calixarenes with 4, 6 or 8 phenolic units are easily available in large quantities and yields higher than 50% by condensation of tert-butylphenol with formaldehyde, while the yields for the formation of calix[5]-or -[7]arenes range from 10-20% only. In contrast to the two other 'major' calixarenes, the chemical derivatization of calix[8]arenes is less developed. 1 This is especially true for the modification of the wide rim. Although the complete debutylation was described, 2,3 as well as subsequent exhaustive substitutions such as halomethylation, aminomethylation, nitration, (chloro)sulfonation, including further modifications of the substituents introduced, exhaustively halogenated calix[8]arenes are unknown 4 . We were interested in such octabromo and octaiodo derivatives, which are suitable starting materials for various modifications, including Pd-catalyzed C-C bond formation reactions such as the Heck, Suzuki, Negishi or Sonogashira cross-coupling ( Figure 1).Attempts to use procedures (Br 2 /CHCl 3 , Br 2 /CHCl 3 /Fe or N-bromosuccinimide (NBS)/2-butanone) described for the bromination of calix[4]arene or its derivatives 5 failed. In all cases only partly brominated products were obtained. Obviously this is mainly due to the lower solubility of calix[8]arene 1a or its octaethers or octaesters. In DMF, however, a homogeneous solution is formed during the simple reaction with elementary bromine at room temperature. The reaction furnished 2a in about 85% yield. The crude product, purified simply by washing with chloroform, was sufficiently pure for further reactions and ether (2b) or ester (2c-f) derivatives were obtained with standard procedures in 60-85% yields. In our opinion the best criterion, to determine the complete bromination and the purity, are sharp singlets observed for the aromatic protons and the methylene protons in 2a-c, completed by sharp singlets for methyl protons in the case of 2b,c and, due to hydrogen bonding, a broader singlet for OH protons in 2a. In contrast the NMR spectra of the octabenzoates 2e,f are less diagnostic, showing sets of broader signals (multiplets), most probably due to restricted conformational freedom caused by the larger O-acyl residues.Based on our experience with the bromination we attempted the iodination with [BnNMe 3 ] + [ICl 2 ] -as described for calix[4]arenes, 6 replacing, however, CH 2 Cl 2 by DMF as the solvent. The octaiodocalix[8]arene 3a was isolated in 73% yield and could be easily converted, with a 92% yield, into the...

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Using a large calixarene as a polyalkoxide ligand: tert-butylcalix[12]arene and its complex with the uranyl cation

Cited by 32 publications

References 9 publications

Actinyls in Expanded Porphyrin: A Relativistic Density-Functional Study

Actinyls in Expanded Porphyrin: A Relativistic Density-Functional Study

Removal of uranyl ions by p-hexasulfonated calyx[6]arene acid

Extended Calix[8]arenes by Sonogashira Cross-Coupling with Ethynylarenes

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