the solvent extraction of rare earth metal ions from nitrate solutions by 5.11.17.23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-dihydroxycalix[4]arene (l) in 1,2-dichloroethane has been investigated. the alalysis of the extraction equilibrium obtained from a mixture of la3+, eu3+, er3+ and y3+ revealed that the extracted species have a 1:1 metal/ligand ratio. the intra-group sepa...

The ability of the hydrosoluble ruthenium(II) complexes [RuCl2(h-arene)(PTA)] 3a–d, [RuCl2(h-arene)(PTA-Bn)] 4a–d, [RuCl2(h-arene)(DAPTA)] 5a–d, [RuCl2(h-arene)(TPPMS)] 6a–d (arene = C6H6, p-cymene, 1,3,5-C6H3Me3, C6Me6) to promote the atom-economic formation of b-oxo esters, by addition of carboxylic acids to terminal propargylic alcohols in water has been explored. Scope, limitations and cata...

The conformational behavior of monosubstituted tri-methylsilyle ethynyl Derivative of Cal ix[4]arene as a newgeneration of Caliarene was compared with tetra alkylated calyx[4]arene. The most important conformationalphenomena in these compounds which are pinched cone interconversion process were done by semi-empiricalmethod and ab initio calculations with Gaussian 98w programming.

siilver tetrafluoroborate complex of 5.11.17.23-tetra-tert-butyl-25-26,27,28-tetrakis (diphenylphosphinoylmethoxy)calyx[4]arene (l) has been synthesized by reaction of silver tetrafluoroborate and l in dichloromethane at room temperature. the complex formed has a 1:1 metall/ligand ratio. 1h and 31p nmr data support an encapsulated structure of the complex in which silver ion is located inside t...

New ferrocene substituted calix[4 and 5]arenes have been prepared and the crystal structure of a lower-rim substituted bis ferrocene calix[4]arene (7) has been elucidated. The respective ferrocene/ferrocenium redox-couples of compounds 6 (a calix[4]arene tetra ferrocene amide) and 8 (a calix[5]arene pentaferrocene amide) are shown to be significantly cathodically perturbed in the presence of an...

a new cesium ion selective pvc membrane based on parent calix [4] arene was developed for potentiometric determination of cesium in environmental samples. the electrode based on p-5,11,17,23tetra(tertbutyl) 25,26,27,28-tetrahydroxy calix[4]arene(thc) as ionophor ,dibutyl phthalate (dbp)as plasticizer ,sodium tetra phenyl borate(natpb)and oleic acid as lipophilic salt and additive showed the bes...