SYNTHESIS AND CHARACTERIZATION OF COPPER, NICKEL, COBALT 2-FORMYLURACIL THIOSEMICARBAZONE COMPLEXES. G. Pelosi, M.Belicchi Ferrari, G.Gasparri Fava, P. Tarasconi & R. Rossi, Dip. di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica e Centro di Studio per la Strutturistica Diffrattometrica del CNR, Viale delle Scienze 78, Università degli Studi di Parma, 43100 Parma, Italy

In order to elucidate the biological effects of thiosemicarbazones on Friend erythroleukemia cells (FLC), an extensive work is being carried out in our laboratory on a wide range of derivatives and their transition metal complexes systematically followed by tests in vitro. Most recently our attention has been focused on the influence of the aliphatic/aromatic nature of the ligand and the stereochemistry of the metal ion on the biological activity of this class of compounds. At present we are synthesising and characterising metal complexes of a novel compound: 2-formyluracil thiosemicarbazone (H₃ut). With this ligand we have recently reported the crystal structures of copper- and cobalt-containing complexes prepared starting from their divalent ions chlorides: [Cu(H₂ut)(OH₂)Cl]^.2H₂O, [Cu(H₃ut)Cl₂]^.2H₂O and [Co(H₂ut)₂]0.5(SO₄)^.2.5H₂. The new compounds we are presenting have been prepared by adding H₃ut to Cu(NO₃)₂.3H2O and NiCl₂.6H₂O water solutions. The crystals obtained have the following stoichiometry: [Cu(H₃ut)(OH₂)]SO₄.3H₂O and [Ni(H₃ut)(OH₂)₂Cl]Cl^.H₂O.The former crystallises in space group C2/c, with cell constants a=21.009(5), b=12.174(4), c=14.900(4)Å, [[beta]]=125.44(3)deg.. The copper atom presents a square pyramidal coordination geometry with the basal plane positions occupied by the ligand O,N,S atoms, the fourth position by a water and the apical position by a sulphate oxygen. The latter presents cell parameters of a=16.345(5), b=12.967(4), c=6.756(2)Å and [[beta]]=92.40(1)deg., space group P2₁/c. The nickel atom coordinates octahedrally six donor atoms: the equatorial positions are the same as the previous compound while the two apexes are occupied by a water molecule and a chloride ion. The remaining charge on the metal is neutralised by a second chloride ion lying outside its coordination sphere.

M.Belicchi Ferrari, G.Gasparri Fava, P.Tarasconi, G.Pelosi , XXV Congresso Nazionale, AIC, Giardini Naxos, 25-27 September, 54 (1995)

M.Belicchi Ferrari, G.Gasparri Fava, P.Tarasconi, R.Albertini, S.Pinelli, and R.Starcich, J.Inorg. Bioch., 1994, 53, 13 and refs. therein.