| The thesis deals with two series of Schiff base: 2, 4-dihydroxybenzaldehyde-salicylhydrazide and 2, 4-dihydroxyacetophenone-salicylhydrazide. Fourteen new compounds of their Cu(II), Ni(II), Zn(II), Mn(II), Co(II), Cd(II) complexes had been synthesized.Elemental analysis, IR, UV/vis, molar electro-conductivity and x-ray single crystal diffraction measurements were used to characterize all the compounds. The ligands were identified by 1H-NMR. The chemical formulae and possible structures of the compounds were proposed based on the characterization. Both ligands HL1 and HL2 are tridentate, coordinating with the metal ions through imidic nitrogen(s), phenolic oxygen(s) and carbonyl oxygen(s).The crystal structure of [Zn2(L1)2(py)2] · 2DMF [Zn2(L2)2(py)2] · DMF, ( py = pyridine, DMF = N, N'-dimethylformamide) were determined by x-ray diffraction. These complexes are all neutral. Their crystal system and space group are monoclinic and P2(1)/c.The crystal data of [Zn2(L1)2(py)2] · 2DMF are a = 24.5015(16) A, b = 10.3868(7) A, c = 28.8550(18) (?), β= 113.1270(10)°, V = 6753.2(8) (?)3, Z = 4, Dx =1.439Mg ·m-3, θ = 0.90-27.50°,μ = 1.13mm-1 . The refinement data are R[F2>2 σ (F2)] = 0.048, ωR(F2) = 0.130, S =1.01.The crystal data of [Zn2(L2)2(py)2] · 2DMF are a = 9.8061(7) A. b = 9.9171(7) (?). c = 23.7427(17) (?). β= 92.545(2)°, V = 2306.7(3) (?)3, Z = 2, Dx =1.445Mg ·m-3, θ = 1.72-26.00°, μ = 1.11mm-1. The refinement data are R[F2>2 σ (F2)] = 0.052, ωR(F2) = 0.140, S=1.08.Within two compounds, the Zn(II) atom has a distorted square-pyramidal coordination surrounding comprised of one N atom and two O atoms from one ligand, one O atom from another ligand, and one N atom from the pyridine molecule. The dinuclear complex has a central Zn2O2 four-membered ring. Two phenolic oxygens of two ligands bridge the zinc atoms.Some of two series compounds were tested by illumination method for their effect on relative survival rate in paddy seed sprouts and almost all the tested complexes...
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