Studies on 4f-metal(III) complexes of N-thiophene-2-carboxamidosalicylaldimine

Abstract

N-(thiophene-2-carboxamido) salicylaldimine (H₂TCS) reacts with lanthanide chlorides in the presence of KOH to give complexes of the type K(Ln(TCS)₂] [Ln=La(III), pr(III), Nd(III), Sm(III), Eu(III), Gd(III) and Dy(III)]. A tentative structure for these complexes has been suggested on the basis of molar conductance, TGA and DTA, magnetic susceptibility, electronic, infrared and¹H and¹³C NMR data. The nephelauxetic ratio ($\bar \beta$), covalency (σ) and bonding parameter (b^1/2) have been calculated from the electronic spectrum of the Nd(III) complex. A coordination number of six around the metal ion has been suggested.