Synthesis and Spectroscopic [Electronic, IR, NMR (1H,13C,89Y)] Characterization of Hexaisopropoxoniobates and -Tantalates of Yttrium(III) and Lanthanides(III)

Hexaisopropoxoniobates/tantalates of lathanides of the type [Ln{(μ-OPr i ) 2 M(OPr i ) 4 } 3 ] (M = Nb, Ln = Y(1), La(2), Nd(3), Er(4), Lu(5); M = Ta, Ln = Y(6), Gd(7)) have been prepared by the reactions of LnCl 3 .3Pr i OH with three equivalents of KM(OPr i ) 6 in benzene. Reactions in 1:2 molar ratio of LnCl 3 .3Pr i OH with KTa(OPr i ) 6 yielded derivatives of the type [{(Pr i O) 3 Ta(μ-OPr i ) 3 }Ln{(μ-OPr i ) 2 Ta(OPr i ) 4 }(Cl)] (Ln = Y(8), Gd(9)), which on interactions with one equivalent of KOPr i afforded [{(Pr i O) 3 Ta(μ-OPr i ) 3 }Ln {(μ-OPr i } 2 Ta(OPr i ) 4 }(OPr i )] (Ln = Y(10), Gd(11)). All these derivatives have been characterized by elemental analyses and molecular weight measurements as well as by their spectroscopic [IR, 1 H and 1 3 C NMR (Y, La, Lu), electronic (Nd, Er)] studies. 8 9 Y NMR studies have also been carried out on derivatives (6), (8), and (10).