Synthesis, thermal and spectral properties of Cu(II) complexes with N,N-diethylnicotinamide

The thermal decomposition of the complexes [Cu(ac)2 .(Et(2)na)]2 . Et(2)na 2H(2)O (I), Cu(Clac)(2)(Et(2)na)(3) (II), and Cu(Cl(2)ac)(2).(Et(2)na)(2). 2H(2)O (III) (where ac = CH3COO-, Clac = ClCH2COO-, Cl(2)ac = Cl2CHCOO-, an d Et(2)na = N,N-diethylnicotinamide) had been investigated in static air in the temperature range 20-1000 degrees C by means of thermogravimetry (TG) and differential thermal analysis (DTA). The composition of the complexes a nd the solid state intermediate and resultant products of thermolysis had b een identified by means of elemental analysis and compleximetric titration. The possible scheme of destruction of the complexes is suggested. Heating the compounds first results in a release of water molecules. The loss of th e volatile ligand (Et(2)na) occurs in one step. The thermal stability of th e complexes increases in the sequence: II, II I. The final products of the thermal decomposition were CuO. The IR, EPR, and electronic spectral analys es were used. Et(2)na was found to be coordinated to Cu(II) through the nit rogen atom of its heterocyclic ring and EPR data suggest a dimeric structur e of compound I and monomeric structure of compounds II and III.