Synthesis and Spectroscopic [Electronic, IR, NMR ( 1 H, 13 C, 89 Y)] 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 13 C NMR (Y, La, Lu), electronic (Nd, Er)] studies. 89 Y NMR studies have also been carried out on derivatives ( 6 ), ( 8 ), and ( 10 ).