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Chromojonofory kaliksarenowe

Przygórzewska J., Rakoczy P., Rokicki G.

Wiadomości Chemiczne

2003

[Z] 57, 1-2

43--62

The condensation reaction of p-tert-butylphenol with formaldehyde leads in one step, with relatively high yield, to macrocyclic phenol-formaldehyde tetramer - calix[4]arene. This calixarene easily undergoes modification in the reaction with various substrates and a macrocyclic product functionalized at both 'narrow' and 'wide' rims can be prepared. According to this way, various calixarene derivatives exhibiting properties of selective complexation of various species can be obtained. The majority of applications of calix[4]arenes and their derivatives are focused on selective complexation of cations and anions. The review demonstrates the possibility of syntheses of calixarenes with chromoionophoric properties. Usually, urea groups are used as anion binding receptors and chromogenic groups are introduced into the calixarene structure in close proximity to the ion-binding site. Methods of synthesis of chromoionophoric calixarenes able to complex selected anions were elaborated. In these calixarenes urea groups were connected to the calixarene ring in the reaction of an amine derivative with chromophoric isocyanate or active urethane. Several derivatives with naphthylurea and other chromophoric groups were prepared. The chemical structures of chromoionophoric calixarenes were confirmed by elemental analysis, as well as IR and proton NMR spectroscopies. It was found that calixarene ionophore with chromogenic urea groups show changes in the 1H NMR and phosphorescence spectra in the presence of nitrate, dihydrophosphate and hydrophosphate anions. Chromogenic ditopic calixarene containing ester groups at the narrow and naphthylurea groups at the wide rim of calixarene was also described. The complexation of sodium ions by ester groups and dihydrophosphate anions by urea groups was confirmed via changes in the NMR spectra. The method of obtaining and preliminary properties of the calixarene macromonomer, which possesses the ability of selective dihydrophosphate anions complexation, are also presented. The complexing properties of the macromonomer were very similar to that of the symmetric calixarene with four naphthyl urea groups at the wide rim. The resulting calixarene macromonomer containing chromophoric receptor groups (urea) and polymerizable group (allyl) is going to be covalently bonded with the polymer matrix by copolymerization with acrylic comonomers.

New lithium selective chromogenic crown ethers

Wagner-Wysiecka E., Luboch E., Kłonkowski A., Biernat J.F.

Biocybernetics and Biomedical Engineering

2001

Vol. 21, no. 4

67-85

New proton-dissociable crown compounds resembling mordant azo dyes were prepared and investigated. Molecules of the chromoionophores constitute of: polyoxyethylene residues and two azo chromophores forming macrocycle, and phenolic OH residue. As a proton dissociable group also azole NH groups were chosen. Many of the compounds are valuable reagents for recognition of lithium cations with largc separations of spectral bands for the ligands and their complexes with alkali metal cations. Derivatives of phenols and resorcinol selectively recognize lithium ions in dioxane-water solutions at high pH. Derivatives of azoles recognize lithium in neutral acetonitrile solutions. Stability constants of the respective complexes were determined. Thc chromoionophores with phenol residues were immobilized in an organic-inorganic hybrid xerogels. Opposite to solutions, some of these materials recognize lithium cations on contact with their neutral aqueous salt solutions.

Syntezowano zdolne do oddysocjowania protonu związki koronowe o konstytucji zbliżonej do lakowych barwników azowych i badano ich właściwości. Cząsteczki tych chromojonoforów zawierają fragment polioksyetylenowy i dwa chromofory azowe tworzące makrocykl oraz fenolową grupę OH. Jako grupę zdolną do oddysocjowania protonu wybrano też resztę NH azoli. Wiele z tych związków to wartościowe odczynniki do rozpoznawania kationów litu charakteryzujące się znacznym rozdzieleniem pasm widmowych dla ligandów i ich kompleksów z kationami metali alkalicznych. Pochodne fenoli i rezorcynolu selektywnie rozpoznają jony litu w roztworach woda-dioksan przy wysokich wartościach pH. Chromojonofory z fragmentem fenolowym były immobilizowane w hybrydowych nieorganiczno-organicznych kserożelach. W odróżnieniu od roztworów, niektóre z tych materiałów rozpoznają sole litu po zetknięciu z ich obojętnymi wodnymi roztworami.