Thermal dissociation of some nitrogen ligated complexes of 2-quanidinobenzimidazole (GMB). - 1,2-dimorpholinoethane (DME) and 1,3­dimorpholinopropane (DMP) ~~ith Ni (11), Cu(II) Zn(II), Cd(I), Hg (II) and Mn(II) have been studied by thermogravimetry and few compounds by differential thermal analysis. The thermal decomposition of SBM, DME and DMP complexes with transition metals was generally obselV<:u occur in two stages. The dissociation sequence observed for GBM complexes was such that the ligand was lost in the second stage of dissociation. However DME and DMP chelates were found to follow entirely different decomposit-ion mechanism. In DMP chelates the ligand was lost in the first stage of dissociation followed by the elimination of halogens. DME compl~xes, unlike DMP chelates, loses part of the ligand, one morpholine moiety, in the fi rst stage and morphol i no-ethane moiety in the second stage of dissociation. The non-transition metal complex of all the three ligands follow the same sequence of decomposition and analysis of Ni(II) complexes are also reported. The react ions found in DTA curves correspond well to those found in the TGA curves.


T ALI ,A WADUD ,H A RASHID ,