Synthesis and characterization of dinuclear complexes of niobocene dichloride with some β-diketonates

Abstract

The synthesis and characterization of some dinuclear niobocene complexes of β-diketonates having niobium-niobium interaction are reported. The reactions of Cp₂NbCl₂ (I) with sodium salts of β-diketones viz., benzoylacetone (bzac), dibenzoylmethane (dbm), 2-thenoyl trifluoroacetone (tfa), 2,2,6,6-tetramethylheptane dione (tmhd), acetylacetone (acac), 1,1,1,5,5,5-hexatluoropentanedione (hfpd)and 3-methyl-2,4-pentanedione (mpd) in 1:1 and 1:2 ratios respectively led to the formation of complexes of the types [CP₂NbL₂]₂ and (Cp₂NbL₂]₂ (where L= β-diketonate anion), The resulting dinucIear complexes have been characterized on the basis of elemental analyses, magnetic moment data and spectral techniques (IR, ¹H NMR and ¹³CNMR). The magnetic moment data show diamagnetic character of the complexes indicating Nb-Nb bonding.