SPECTROPHOTOMETRIC STUDY OF THE LANTHANIDE(III) IONS SOLVATION IN COMPLEXES WITH DBP18C6 AND DB18C6

The macrocyclic compounds 1,4,7,14,23-pentaoxa[7,2] orthocyclo[2] (2-6 )pyridinophan; (DBP18C6) and 1,4,7,14,17,20-hexaoxa[7,7] orthocyclopha n; (DB18C6), used as ligands in the complexes with Eu(CLO(4))(3) and T b(CLO(4))(3), were examined. A series of absorption spectra of Eu(III) subset of DBP18C6 and Tb(III) subset of DBP18C6 complexes was obtaine d by spectrophotometric titration with the lanthanide ions as a titra nt and usi ng CH3CN and CH3OH as solvent at different volume ratios. T he analysis of absorption spectra has shown a different influence of t he mixed solvent on absorbance of the complexes investigated. An analo gous investigation carried out with DB18C6 similar to DBP18C6 has led to the conclusion that the presence of the pyridine ring in DBP18C6 in fluences the effects observed.