Mononuclear Manganese(II) and Chromium(III) Complexes of Pentadentate Macrocyclic Ligands Derived from 2, 6-Diacetylpyridine

New metal complexes of the type [M(DAP-Ch-DAP)H2O]X2or3 and [M(DAP-Th-DAP)H2O]X2or3 [where M = Mn(II) or Cr(III); DAP-Ch = 2, 6-Diacetylpyridinebis(carbohydrazide), DAP-Th = 2, 6-Diacetylpyridinebis-(thiocarbohydrazide);X = ClorOAc] have been synthesized and characterized by analytical methods, infrared spectral data, conductivity measurements and thermal studies. The pyridine nitrogen, two azomethine nitrogens and two amide (ketonic) oxygen atoms in case of DAP-Ch-DAP and two thioamide sulphur atoms in case of DAP-Th-DAP take part in nucleophilic condensation and coordination to metal ions. The mononuclear products, their synthetic procedures, reactions and their spectral and thermal studies are reported.