Complexes of rare earth perchlorates with 4-N-(4'-antipyrylmethylidene)aminoantipyrine

Rare earth perchlorate complexes with the Schiff base 4-N-(4'-antipyrylmethylidene)aminoantipyrine (AA) of the types [Ln(AA)(2)ClO4](ClO4)(2) (where Ln = La, Pr, Nd, Sm and Eu) and [Ln(AA)(3)](ClO4)(3) (where Ln = Gd, Dy, Ho, Er and Y) have been synthesised and characterised. In these complexes AA acts as a terdentate ligand. One of the perchlorate groups is coordinated monodentately only in the complexes of the light rare earths, whereas in the heavy rare earths perchlorate groups remain uncoordinated. The magnetic moments of these complexes agree well with the van Vleck values, suggesting non-participation of f-electrons in bonding.