Structural chemistry of modified zirconium (IV) complexes: Preparation, spectroscopic characterization and DFT assisted optimized molecular structure of C₅₀H₃₈Cl₂N₄O₁₀Zr

Abstract

Three structurally modified mixed ligand zirconium(IV) complexes of formula [Zr(L1)2(A)2] (1), [Zr(L2)2(A)2] (2) and [Zr(L3)2(A)2] (3) (where L1H= 4-acetyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one, L2H= 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one, L3H= 4-p-chlorobenzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one and AH=2-hydroxy-2-phenyl acetic acid) were synthesized by the reactions of zirconium(IV) tetrachloride with sodium salts of sterically impeded substituted pyrazolones and hydroxy carboxylic acid in 1:2:2 molar ratio in refluxing dry THF. The plausible structures of these modified complexes were suggested on the basis of analytical, spectroscopic (IR, 1H and 13C NMR) and mass spectrometry studies. Obtained evidences proposed a hexa coordinated geometry around the zirconium metal center in these newly synthesized mixed ligand zirconium(IV) complexes. Theoretical calculations (DFT) were performed to support the experimental findings and to study the electronic properties, optimized energy, optimized molecular geometry and stability of one of the representative complex, [Zr(L3)2(A)2].