Template Synthesis of Macrocyclic Complexes of Bivalent CoII, NiII, PdII,ZnII and CdII Ions with Cyclic Glyoxal Carbohydrazone (1,2,4,5,8,9,11,12-octaazacyclotetradeca- 5,7,12,14-tetraene-3,10-dione)

Cyclic glyoxalcarbohydrazone[(1,2,4,5,8,9,11,12-octaazacyclotetradeca-5,7,12,14tetraene-3,10-dione) = (glyozalcarbzH)2] complexes of Ni II, PdII, CoII, ZnII and CdII of composition M (glyoxalcarbzH)2X2nH2O (M = Ni II, PdII, CoII,ZnII or CdII and X = Cl> , 1/2 SO4 -2 and n = 0,1 or 4) have been isolated by refluxing appropriate metal salts with glyoxal and carbohydrazide in requisite proportion for 8 to 10hours in aqueous ethanol on steam bath. The refluxate on concentration and cooling in ice gave crystalline precipitate of appropriate complexes. The complex salts are soluble in hot aqueous ethanol and conduct electricity showing 1:2 ionic natures. Except ZnII, CdII and PdII the complexes of CoII and NiII are paramagnetic and their magnetic moment value suggested octahedral geometry. The UVand IR spectral results supported octahedral structure for CoII and NiII while planer for PdII complexes. Key word: Cyclic glyoxalcarbohydrazone, bivalent metal complexes.