Synthesis,Structure And Properties Of Transition Metal Complexes Based On Pyridyl-Triazole Or-Acylhydrazone

In present work, based on four kinds of transition metal ions (Co2+、Cu2+、Mn2+、Mn3+) as paramagnetic centres and the diversified coordination modes of two organic ligands, 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole (4-Hppt) and N3-benzoylpyridine-2-carboxamidrazonato (Hbpad), seven new coordination compounds, [Co(4-Hppt)2(ip)] (1), [Cu2(bpad)2(Hp)2]n (2), [Cu2(bpad)2(Hip)2]n (3), [Mn(bpad)2] (4), [Mn(Hbpad)(mnb)2(H2O)] (5), [Mn2(Hbpad)2(p)2]-H2O (6) and [Mn2(bpad)2(CH3O)4] (7) have been successfully synthesized with rigid aromatic acids as coligands, and systematically characterized by infrared spectra analysis, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffraction. The magnetisms of compounds 1-5 have been investigated and discussed. The main contents and conclusions are summarized as follow:1. A new coordination compound, [Co(4-Hppt)2(ip)] (ip= isophthalic acid) (1), has been synthesized by using hydrothermal reaction. X-ray crystal structure analysis determines that the coordination geometry around the six-coordinated Co (Ⅱ) ion is a distorted octahedral structure, and The structure of compound 1 consists of one-dimensional coordination chains based on the Co2 units bridged by dual carboxylate groups. Magnetic investigation suggests that the magnetic coupling derived from the dinuclear Co(II) ions is a moderately antiferromagnetic exchange with the best fit parameters of J=-6.19 cm-1. DFT calculation performs that the calculated coupling constants is J=-3.52 cm-1.2. Two new compounds, [Cu2(bpad)2(Hp)2]n (Hp= pathalic acid) (2), [Cu2(bpad)2(Hip)2]n (ip= isophthalic acid) (3), have been successfully prepared "based on solution method. The structures and magnetic properties of the compounds have been systematically characterized. In isomeric 2 and 3, the penta-coordinated Cu (II) ions diversely exhibit distorted square pyramidal and trigonal bipyramid geometry. For 2 and 3, magnetic investigations demonstrate that dinuclear Cu (II) units performing antiferromagnetic (J=-2.03 cm-1) and ferromagnetic (J= 19.4 cm-1) couplings, respectively.3. Employing solution method, four new compounds, [Mn(bpad)2] (4), [Mn(Hbpad)(mnb)2(H2O)] (mnb= m-nitrobenzoic acid) (5), [Mn2(Hbpad)2(p)2]H2O (p= pathalic acid) (6), [Mn2(bpad)2(CH3O)4] (7), have been successfully obtained. The structures and magnetic properties of the compounds have been explored in detail. The results demonstrate that the geometrical environments around the six-coordinated Mn (II)/Mn (III) ions are consistently distorted octahedral structures in compounds 4-7. For 4 and 5, magnetic investigations exhibit that Mn (II) units present antiferromagnetic (θ=-0.34 K) and ferromagnetic (θ=0.86 K) exchanges, respectively.