TIN(IV), TITANIUM(IV) AND HAFNIUM(IV) COMPLEXES OF SOME AROMATIC SCHIFF-BASES DERIVED FROM 4-AMINOANTIPYRINE

Tin(IV), titanium(IV) and hafnium(IV) chloride complexes of ligands su ch as salicylidene-4-aminoantipyrine (HL1), 5-chlorosalicylidene-4-ami noantipyrine (HL2), 2,4-dihydroxybenzylidene-4-aminoantipyrine (HL3), 2-hydroxy-1-naphthylidene-4-aminoantipyrine (HL4) and 2-hydroxy-acetop henonylidene-4-aminoantipyrine (HL5) have been prepared and characteri zed. The analytical data show that tin(IV) forms only 1:1 metal comple xes when reacted with HL1, HL3 and HL4, whereas it forms 1:1 and 1:2 m etal complexes when reacted with HL2, depending on the molar ratio. HL 5 produces only the binuclear complex SnHL5Cl4(H2O)SnCl4. Titanium(IV) gives only one type of complex of the general formula [Ti(HL)2Cl2]Cl2 . 2H2O, whilst hafnium(IV) gives HfHL3Cl4.4H2O and Hf(L5)2Cl2.