Phosphine oxide calixarenes

Selective Extraction of Actinides by Calixarenes Bearing Phosphine Oxide Moieties... 

Extraction of thorium nitrate and europium nitrate 0 0 4 M) from 1 M HN03 into dichloromethane was carried out for 19 calixarenes totally or partially substituted on the lower rim by phosphine oxide moieties (CPol-CPol7-CPol9-CPo20) and for one calixarene substituted by phosphinate (CP0I8) (see Section 4.7).IM 152 154... 

The replacement of the phenyl groups on the phosphine oxide moieties by n-butyl groups leads to a complete loss of extraction. Increasing the length of the chain linking the calixarene to the phosphine oxide moieties leads to a decrease of extracting ability of both tetramer and hexamer (Table 4.23). The selectively substituted... 

Other signiflcant complexes of this type, containing one or more lanthanides, are formed by calixarenes (see Calixarenes) Much of this work has been prompted by their potential in separating lanthanides from uranium and other metals. A calixarene ligand with two amide substituents has been synthesised as an extractant for lanthanides dimeric Sm and Eu and monomeric Eu complexes have been prepared. Another calixarene, with four phosphine oxides attached, has been fixed to silica particles and the resulting system has been found to give very efficient extraction of Eu + and Ce + from simulated waste. A calix[4]arene complex of Gd + binds... 

Phosphine Chalcogenides as Ligands. - The complexation of lanthanide and actinide ions by phosphine oxide ligands remains an active area, and a theoretical assessment of the coordination of phosphine oxides (and phosphate esters) by trivalent lanthanide ions has appeared." Trivalent lanthanide complexes of the functionalised enol phosphine oxide (265), (and a related phosphonate), have been describedComplexes of thorium(iv) with bis(di-phenylphosphino) ethane dioxide and bis(diphenylphosphinoyl)amide have also been characterised." Calixarene systems which bear phosphine oxide... 

Kane. P. Kincaid, K. Fayne, D. Diamond. D. McKervey, M.A. Modelling metal complexes of calixarene esters and phosphine oxides using molecular mechanics. J. Mol. Model. 2000. 6. 272-281. 

New calixarenes, mainly calix[4]arenes with phosphine oxide functionality were synthesized (Fig. 1) and the effect of structural modifications on the separation of Eu(III), Am(III) and Cm(III) via complexes was... 

Fig. 35.11 (Left) Calix[4]arene phosphine ligands 20a-c (right) Schematic representation of the 0.9-rnn Aui 1 cluster having five bound calixarene ligands 20a. Two of these calixarene ligands are bound in a bidentate fashion and three are bound in a monodentate fashion. The monodentate ligands consist of bound phosphine and unbound phosphine-oxide substituents (Adapted with permission from Ref. [52], Copyright 2010 Macmillan Publishers Limited)...

Fig. 37.17 Chemical structure of the calixarene-phosphine ligand (a) and graphical representation of the macrocycle capped Au nanoparticle with the Au core diameter of 0.9 nm and five calixarenes bound to metal surface (b). Two calixarenes bind the metal core with two phosphines while the other three with only one phosphine. The monodentate ligand possesses one phosphine bound to the metal surface and one unbounded phosphine oxide (Reproduced with permission from Ref. [106], Copyright 2010, Nature Publishing Group)...

STRUCTURE 19.3 (a) Tetrafunctionalized cavitands (tetrakis(diphenyl-(N-methylcarbamoyl) methyl phosphine oxide) cavitand for IR = H, 2R = Ph), (b) calixarene-based picolinamides (5,11,17,23,29,35, 41,47-octakis(phenylmethoxy)-49,50,51,52,53,54,55,56-octakis 3-[(pyridine-2-carboxy)amino]propoxy calix[8]arene for n = S,m = 3,R = OBn). 

Calix[n]arenes (n = 4, 6) existing in the cone, 1,3-alternate or 1,3,5-alternate conformations and functionalized by two, four or six Bu2P(0)CH20 groups were synthesized by the alkylation of hydroxy-calix[4,6]arenes with the tosylate of dibutyl-hydroxymethylphosphine oxide (Schemes 27-1, 27-2 and 28). In the preparation of another calixarene, the benzyl chloride moieties alkylated the hydroxy groups of four dibutyl-hydroxymethylphosphine oxide molecules (Scheme 29). Due to the calixarene effect , the phosphine oxides are potential extractants for Ru/Zn complexes. 

Calcium complexes amino acids, 33 arsine oxides, 9 bipyridyl, 13 crown ethers, 39 dimethylphthalate, 16 hydrates, 7, ionophores, 66 peptides, 33 phosphines, 9 pyridine oxide, 9 Schiff bases, 29 urea,9 Calixarenes... 

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