Raman spectral studies of the complexes of biuret with metal(II) halides

As the biuret can adopt either the cis- or the trans-configuration in its c omplexes, the Raman spectra have been measured for the complexes of biuret with metal(II) halides and the modes of coordination, of ligand in all thes e complexes,have been established. The complexes N(biuret)(2)X-2 (M = Mn & Co; X = Cl or Br and M = Ni and Zn; X = Cl) have been found to contain biur et in the cis-configuration, coordinating with metal ions through both of i ts carbonyl oxygen atoms. On the other hand, complexes M(biuret)(2)Cl-2 (M = Ca, Cd and Hg) and Cd(biuret)(2)Br-2 contain biuret in the trans-configur ation, coordinating through one of the two carbonyl oxygen atoms. These res ults are consistent with the previously reported I.R and E.S.R. spectral st udies [1,2].