Spectroscopic studies of lanthanides complexes with diethyl benzylphosphonate and diethylphosphonoacetic acid

Spectroscopic properties of Ln(III) complexes with diethyl benzylphosphonate (PhCH2P(O)(EtO)2) and diethyl (carboxymethyl)phosphonate ((EtO)2P(O)CH2COOH) were investigated using absorption and luminescence spectroscopy. Absorption spectra of organophosphorus ligand with Nd(III) were measured in acetonitril solution and oscillator strength values and Judd–Ofelt parameters were calculated. Excitation and luminescence spectra of Eu(III) and Tb(III) ions with diethyl benzylphosphonate were measured. Energy transfer was observed from PhCH2P(O)(EtO)2 ligand to Tb(III) ion and quantum yield (Φf = 0.04) was determined. The Eu(III) selective excitation spectra of 5D0 ← 7F0 band in Eu3+/PhCH2P(O)(EtO)2 and Eu3+/(EtO)2P(O)CH2COOH system were recorded in order to evaluate the number of species forms observed in studied systems and luminescence lifetimes of Eu(III) ion have been determined from those spectra.The La(III) and Pr(III) complexes with the studied ligands were synthesized and their structures were confirmed by elemental analysis, IR spectra and also 13C and 31P-NMR.