Synthesis, spectral and antibacterial studies of bis(cyclopentadienyl) titanium(IV)/zirconium(IV) and mono(cyclopentadienyl)titanium(IV) complexes of antipyrine Schiff bases

The reactions of mono(cyclopentadienyl)titanium(IV) trichloride and bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloride with Schiff bases, derived by condensing 4-aminoantipyrine with benzaldehyde (L₁), furfuraldehyde (L₂), pyridine-4-carboxaldehyde (L₃) or salicylaldehyde (L₄H), have been studied in anhydrous tetrahydrofuran or dichloromethane and products of types [Cp₂M(L)Cl]Cl, [CpTiCl ₃(L)] (L = L₁, L₂ or L₃); [Cp ₂M(L₄)]Cl, [CpTiCl₂(L₄)], [CpTi(L₄)₂]Cl [M = Ti^IV or Zr^IV] have been isolated. Tentative structures are proposed for these complexes based upon elemental analyses, electrical conductance and spectral (electronic, IR, ¹H NMR and ¹³C NMR) data. Attempts have been made to establish a correlation between antibacterial activity and the structures of the products.