Mössbauer spectra of Eu(III) and Gd(III) complexes of phosphine oxides with chelating perchlorate

Abstract

The reaction of Ln(ClO4)3· nH2O with triphenylphosphine oxide (TPPO) in methanol has led to the formation of [Ln(ClO4)2(tppo)4]ClO4·MeOH (Ln = Nd, Eu, Gd, Dy, Yb), in which the perchlorate anion acts as a symmetric bidentate. The emission spectra of Eu(III)-TPPO complexes, showing enhancement in the intensity due to the phenyl group, indicate an isotropic electron distribution for the nitrato complex [Eu(NO3)3(tppo)2(EtOH)]. 151Eu and 155Gd Mossbauer spectra of the TPPO complexes also lead to the same conclusion.