NICKEL(II) AND PALLADIUM(II) CHELATES OF DEHYDROACETIC ACID-SCHIFF BASES DERIVED FROM THIOSEMICARBAZIDE AND HYDRAZINECARBODITHIOATE

Dehydroacetic acid Schiff bases DAE (1) and DATS (2) were isolated fro m the reaction of dehydroacetic acid (2-acetyl-5-hydroxy-3-oxo-4-hexen oic acid-delta-lactone) with hydrazine-S-methylcarbodithioate and the corresponding acid amide, thiosemicarbazide, respectively. Reaction of such Schiff bases with nickel(II) and palladium(II) ions afforded the dimeric monoligand chelates [M(DAE-2H)](2) and [M(DATS-2H)](2); M = N i(II) or Pd(II). In the presence of monodentate Lewis bases, B, square -planar chelates [M(DAE-2H)B] and [M(DATS-2H)B], in which B = pyridine or triphenylphosphine, were isolated. The stoichiometry and structure of the isolated organic ligands and their chelates were confirmed thr ough elemental analyses, molecular weight determination, and infrared, ultraviolet-visible, and H-1 and C-13 nuclear magnetic resonance spec troscopy.