TEMPLATE CONDENSATION REACTIONS 1VIII. Cr(III), Ni(II) AND Cu(II) COMPLEXES RESULTING IN THE SYSTEM 5,5`-DIETHYLBARBITURIC ACID – ETHYLENEDIAMINE

A series of new complexes of Cr(III), Ni(II) and Cu(II) with with general formula[ML(NO3)2](NO3)n mH2O (where L is the Schiff base resulting in [3+2] condensation of5,5`-diethylbarbituric acid (DEBA) with ethylenediamine (en), (1) M=Cr, n=1, m=2;(2) M=Ni, n=0, m=2; (3) M=Cu, n=0, m=3 have been synthesised and characterised. The freeligand has been isolated by treatment of Cu(II) complex with potassium cyanide. The bondingand stereochemistry of the complexes have been characterised by IR, EPR and, electronicspectroscopy, magnetic susceptibility at room temperature and conductivity measurements. Theresults concerning the thermal behaviour of complexes (2) and (3) are presented. The ligandbehaves as tetradentate and coordinates through the azomethynic nitrogen atoms and nitratebehaves as monodentate.