Lanthanide 2-thenoates

Ln(C5H3SO2)3, Ln(C5H3SO2)2(OR) and Ln(C5H3SO2)(OR)2 (where Ln=La, Pr, Nd, Sm, Tb, Gd and Dy; C5H3SO2=2-thenoate anion, and OR=OPr-i or OBu-t) were prepared and characterized by elemental analysis, electronic and i.r. spectral measurements. Electronic absorption spectra show that chelates have a certain degree of covalency compared to the aquo ion. The i.r. spectra indicate interaction of ring sulphur to the metal atom in these carboxylates. Small Δv values suggest symmetrically bonded bidentate carboxylate groups.