Infrared luminescence of ytterbium ion in complexes with calix[4]resorcinarenes

New ytterbium complexes with seven calix[4]resorcinarenes containing methox ycarbonyl, methyldiethylamino groups, and bromine as the substituents in th e resorcinol ring and methyl or phenyl substituents in the macro ring were synthesized. The absorption, excitation, phosphorescence, and luminescence spectra of these complexes were studied. The positions of triplet levels of the ligands were measured and the values of relative quantum yields for th e complexes were calculated. The paths of ligand-lanthanide energy transfer are discussed.