[Preparation and properties of complex of europium lanthanum with crown ether and p-phthalic acid].

Two complexes of crown ether europium (EuL) and crown ether lanthanum (LaL) were synthesized by europium perchlorate and lanthanum perchlorate with 18-crown-6(18-C-6) respectively. The heternuclear complexes of europium-lanthanum p-phthalic acid crown ether were prepared by the two complexes (EuL and LaL) with p-phthalic acid. The elemental analysis shows that its composition is EuLaL2L'(ClO4)4.6H2O(L = 18-C-6 and L' = p-C6H4 (COO)2). The IR spectra, UV-spectra and molar conductor indicate that both ligands (L and L') coordinate rare earth ions (Eu3+ and La3+), but perchlorate group is free. The fluorescence spectra show that the fluorescence intensities of the complex of heternuclear (EuLaL2L'(ClO4)4.6H2O) are more than eight times that of the crown ether europium complex. It was shown that the linked ligand (p-phthalic acid) can transfer the absorbed energy of Lanthanum-crown ether to europium-crown ether with high efficiency.