High Complexation Ability of Thiacalixarene with Transition Metal Ions. The Effects of Replacing Methylene Bridges of Tetra(p-t-butyl)calix[4]arenetetrol by Epithio Groups

Abstract

The ability of tetra(p-t-butyl)tetrathiacalix[4]arenetetrol (TCA, H4L), a cyclic tetramer of p-(t-butyl)phenol bridged with four epithio groups, to bind metal ions was investigated via a solvent extraction study. Although tetra(p-t-butyl)calix[4]arenetetrol (CA) has very poor affinity for transition metal ions (M2+), TCA is an excellent extractant of these metal ions. The chemical formulae of the extracted TCA metal complexes were found by slope analysis to be neutral 1 : 1 complexes [MH2L]. The origin of the high affinity of TCA for transition metal ions is discussed, in which it is suggested that ligation of the epithio group is important as evidenced by an NMR study of the [ZnH2L] complex.

Extraction Property of p-tert-Butylsulfonylcalix[4]arene Possessing Irradiation Stability towards Cesium(I) and Strontium(II)

“…It could be determined from Figures 3-5 that the extracted species of Cs(I) and Sr(II) with SC4A are Cs¨SC4A and Sr¨2SC4A, respectively, the extraction equilibrium of Sr(II) is similar to that reported in the literature [35], and can be expressed as follows:…”

“…Therefore, increasing the operation temperature in the experimental conditions adversely affected the extraction. It could be determined from Figures 3-5 that the extracted species of Cs(I) and Sr(II) with SC4A are Cs•SC4A and Sr•2SC4A, respectively, the extraction equilibrium of Sr(II) is similar to that reported in the literature [35], and can be expressed as follows: (4) where H4L and Sr•2H3L are free SC4A and Sr-SC4A complex.…”

Solid-phase extraction technology for actinide and lanthanide separations in nuclear fuel reprocessing

“…The separation of the MA from Ln is, however, a diffi cult chemical separation to achieve as there are minor differences in the chemical properties of these elements. Studies in recent years have shown that ligands containing soft donor atoms such as N and S offer a higher probability of being more selective for An(III) elements (Kikuchi et al, 2004, Zhu, 1995, Modolo et al, 1998b, Wei et al, 2000a, Iki et al, 1998, Morohashi et al, 2001, Mathur et al, 2001. Although the exact mechanism for this preferential complexing behavior has not been entirely elucidated, many researchers are investigating the merits of using soft donor ligands in solid-phase extraction to perform An(III) separations from Ln(III) elements in high level liquid waste (HLLW) solutions subsequent to upstream removal of U and Pu.…”

Protective effect of tiacalix[4]arene-tetrasulphonate on heavy metal inhibition of myometrium myosin subfragment-1 ATP-hydrolase activity

“…1, б) [18]. Верхній вінець макроциклу містить чотири аніонні сульфонатні угруповання, котрі забезпечують гарну водорозчинність тіакаліксарену та адгезію до протеїнових молекул за рахунок електростатич них контактів із позитивно зарядженими атома ми азоту амінокислотних фрагментів [19].…”