STUDY ON SOME BIOLOGICALLY ACTIVE CO-ORDINATION COMPOUNDS OF METAL IONS (Ⅰ)——SYNTHESIS,CHARACTERIZATION,STRUCTURE AND ANTITUMOR ACTIVITY OF COMPLEX OF 3,6-DI-(DIMETHYLAMINO)-DIBENZOPY-RIODONIUM LANTHANUM EDTA

The title coordination compound has been synthesized by the reaction of HLaEDTA·7H2Owith （CH3）2N-?-N（CH3）2·HCOO- in ethanol aqueous solution. Thesingle crystal has grown from aqueous solution and has been characterized by IR, TG-DTA,X-ray powder diffraction, molar conductance, UV and 1H-NMR. The determination of itscrystal and molecular structure shows that it crystallizes in space group P21/n with latticeparameters: a = 14.735A, b = 29.335A, c = 16.409A, β = 99.24°, v = 7009.30A3, z = 4,F（000） = 3488, molecular weight M = 1756.90, DC = 1.665g/cm3. It has been refined by thefull matrix least squares method to final discrepancy factor R = 0.096. The anion [La2（EDTA）2（H2O）4]2- turns out to be a dimer, in which each of the twoEDTA4- ions is coordinated to a La3+ ion with five of its six coordinating sites and the re-maining sixth one-the oxygen atom of carboxylis bridged to two La3+ ions, thus forming aparallelogrammic four-membered ring La2O2. The nine coordinations

The title coordination compound has been synthesized by the reaction of HLaEDTA·7H_2Owith (CH_3)_2N-?-N(CH_3)_2·HCOO^- in ethanol aqueous solution. Thesingle crystal has grown from aqueous solution and has been characterized by IR, TG-DTA,X-ray powder diffraction, molar conductance, UV and ~1H-NMR. The determination of itscrystal and molecular structure shows that it crystallizes in space group P2_(1/n) with latticeparameters: a = 14.735A, b = 29.335A, c = 16.409A, β = 99.24°, v = 7009.30A^3, z = 4,F(000) = 3488, molecular weight M = 1756.90, D_C = 1.665g/cm^3. It has been refined by thefull matrix least squares method to final discrepancy factor R = 0.096. The anion [La2(EDTA)_2(H_2O)_4]^(2-) turns out to be a dimer, in which each of the twoEDTA^(4-) ions is coordinated to a La^(3+) ion with five of its six coordinating sites and the re-maining sixth one-the oxygen atom of carboxylis bridged to two La^(3+) ions, thus forming aparallelogrammic four-membered ring La_2O_2. The nine coordinations about each metal arecompleted by two water molecules. The average bond length is 2.560A for La-O and 2.833Afor La-N. Approximately, the dimer belongs to point group Ci with the centre of inversionat the centre of La_2O_2 parallelogram. The antitumor activity of the coordination compound was studied by observing its effecton the incorporation of ~3H-TdR into DNA of leukemia (L7712) cells in vitro. The degree ofinhibition reached 83.9% after exposing 2×10~5 cells per millilitre to 4×10^(-5) mol/L of thecompound for 24 h, being higher than those of its precursors.