Yttrium and lanthanide iodide complexes of N,N′-bis(4-antipyrylmethylidene)ethylenediamine

Abstract

Complexes of yttrium and lanthanide iodides with N,N′-bis(4-antipyrylmethylidene)ethylenediamine (BAME) having the general formula [Ln(BAME) 3I]I 2 (where Ln=Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er) have been synthesised and characterised by elemental analyses, molar conductance in non-aqueous solvents, electronic, infrared and proton NMR spectra as well as thermogravimetric analyses. BAME acts as a neutral bidentate ligand coordinating through both azomethine nitrogen atoms. One of the iodide ions is coordinated. A coordination number of 7 may be assigned to the metal ion in these complexes. The covalency parameters evaluated from the solid state electronic spectra suggest weak covalent character of the metal-ligand bond. The TG data of the lanthanum complex indicate that the complex is stable up to about 145°C and undergoes decomposition in two stages forming lanthanum oxide as the final product.