Rigidified Calixarenes Bearing Four Carbamoylmethylphosphineoxide or Carbamoylmethylphosphoryl Functions at the Wide Rim
Conformationally rigidified tetraCMPO derivatives have been prepared from calix[4]arene bis(crown ether) 4 a in which adjacent oxygens are bridged at the narrow rim by two diethylene glycol links. Acylation of the tetraamine 4 c with the CMPO-active ester 5 b gave the tetraphosphine oxide 6 a, while the tetraphosphinate 6 b and the tetraphosphonate 6 c were obtained by Arbuzov reaction of tetrabromoacetamido derivative 7 with PhP(OEt)2 or P(OEt)3. The extraction ability of these CMPO derivatives was checked for selected lanthanides and actinides and compared with the analogous compounds 1 b, 10 b and 10 d derived from calix[4]arene tetrapentyl ether. All rigidified bis(crown ether) ligands …
ChemInform Abstract: Dissymmetric Calix(4)arenes with C4- and C2-Symmetry. Synthesis, X-Ray Structures, Conformational Fixation, and 1H NMR Spectroscopic Studies.
ChemInform Abstract: Dissymmetric Calix(4)arenes with C2 and C4 Symmetry.
Synthese de tetrahydroxy-octamethyl [1 4 ] Metacyclophane a partir de 3,4-dimethylphenol. Le tetrahydroxy-octamethyl [1 4 ] Metacyclophane reagit avec le bromoacetate d'ethyle pour donner tetrakis [(ethoxycarbonyl) methoxy]-octamethyl [1 4 ] Metacyclophane qui est analyse par diffraction RX
Strontium complexes of calixarene amides in the solid state: structural dependence on the ligand size and on the counter ions
For the first time, crystal structures of three strontium complexes of calixarene amides have been determined. A p-tert-butylcalix[6]arene hexaamide forms a 1∶1 complex with Sr(Pic)2 (Pic = picrate), whereas p-tert-butylcalix[8]arene and p-methoxycalix[8]arene octaamides encapsulate two strontium cations each. The binding geometries of the metal cations depend on the ligand size and on the counter anion used (chloride or picrate).