Spectral intensities of lanthanide perchlorates in amide solvents

Abstract

The absorption spectra of Nd, Ho, Er perchlorates in N-methylformamide and N,N′-dimethylformamide were investigated. Judd—Oefelt method of intensity analysis was applied to determine the symmetry and structure of the lanthanide amide solvates. The lanthanide perchlorates in amide solvents behave as the electrolytes of the 1∶3 type. In the first coordination sphere of lanthanide ion only amide molecules are present, hence in the first approximation the symmetry factor is responsible for the changes of the intensity of 4f−4f transitions. It was found that both for light and heavy lanthanide solvates no difference exists between mono and dimethylformamide. The symmetry for light lanthanide solvates was established asC _3v (with possible coordination number 9). For heavy lanthanide solvates however the lower symmetry group of lanthanide ion environment should be expected (C _2v ).