Metal Formate Hydrazines M HCOO

Metal formate hydrazines M(HCOO)2(N2H4)2 (where M = Mn, Co, Ni, Zn, and Cd) are prepared by the addition of excess hydrazine hydrate to the corresponding metal formate hydrates [10]. The reaction is instantaneous with the evolution of heat  

The complexes obtained are filtered off, washed with alcohol first and then with diethyl ether, and dried over phosphorus pentoxide. 

The spectral data clearly show the presence of bridged hydrazine by the characteristic absorption at 980 cm . Based on the absorption frequencies of symmetric and asymmetric stretching of -OCO— it has been concluded that M-0 bonds in these complexes are essentially electrostatic. The formate ion is reported to be monodentate and the magnetic susceptibility values obtained are evidence for the bridging nature of hydrazine and the monodentate nature of the formate ion. 

Metal formate hydrazines exhibit autocatalytic combustion behavior when heated rapidly. Although TG/DTA shows endothermic decomposition in the beginning, combustion of these complexes is exothermic, since both hydrazine and formate undergo oxidation simultaneously. 

---