Synthesis, Structure And Characterization Of Transition Metal Complexes Of 4-acyl Pyrazolone Hydrazide And Hydrazone

Coordination chemistry is one of the most active research fields. The design, synthesis and relative properties of functional coordination compounds are focus in the field of coordination chemistry. Research on 4-acyl pyrazolone derivatives has also received considerable attention because 4-acyl pyrazolone derivatives have potential to form different types of coordination compound due to tautomeric effect of enol form and keto form. The compound of pyrazolone derivatives and their transition metal complexes have broad-spectrum anti-viral, antitumor and antisepsis biological activity. Therefore, 4-acyl pyrazolone derivatives are widely used in biological, clinical, analytical applications and extraction metallurgy. Meanwhile compounds of hydrazide and hydrazone which possess biological activity exhibit different coordination modes and its phenoxy is capable of chelate and bridge properties. So we expect the formation of polyfunctional ligands and polynuclear metal complexes using the combination of 4-acyl pyrazolones and hydrazide and hydrazone.In order to further enrich and extend the studies on the functional complexes, such as predetermination of molecular architectures and the properties of the binuclear or multinuclear complexes, 11 novel 4-acyl pyrazolone derivatives and their transition metal complexes have been synthesized and characterized on the basis of elemental analyses, IR spectra and single crystal X-ray diffractions. The general formula of the complexes and the crystal structures were ensured. And the UV–Vis absorption spectra and fluorescent properties have been discussed primarily. The paper consists of four parts:In the first part, four 4-acyl pyrazolone derivative (4-acetyl-pyrazolone-5)- salicylidene hydrazide are prepared and their transition metal (Zn(II), Cd(II), Cu(II), Mn(II)) complexes have been synthesized and characterized by elemental analyses, IR spectra, single crystal X-ray diffractions, UV–Vis absorption spectra and fluorescent properties. X-Ray diffraction analyses of eight single crystals reveal that the N(2) atoms of the pyrazolyl heterocycles play an important role in building the infinite two- and three-dimensional networks, novel hexanuclear unit, the 1D polymer chain and supramolecular chain. The results show the ligands with hydrazide which have sound coordination properties can form the polynuclear or polymer complexes. And the reasons of the differences of structures formed by the same ligand but different metals or the same metal but the different ligands are also studied primarily.In the second part, three 4-acyl pyrazolone derivative (4-acetyl-pyrazolone-5)-p- nitrobenzoylhydrazide and their transition metal (Zn(II), Cd(II), Cu(II), Mn(II)) complexes have been synthesized and characterized by elemental analyses, IR spectra, single crystal X-ray diffractions, UV–Vis absorption spectra, fluorescent properties. X-Ray diffraction analyses of four single crystals reveal that the N(5) atoms of the hydrazide heterocycles play an important role in building the infinite two-dimensional networks, the 1D polymer chain and supramolecular chain.In the third part, three 4-acyl pyrazolone derivative (4-acetyl-pyrazolone-5)- isoniazid and their Mn complexes have been synthesized and characterized by elemental analyses, IR spectra and single crystal X-ray diffractions. The results show the coordination geometry around the Mn complexes is octahedron of about these ligands. The Mn complex of N-(1-phenyl-3-phenmethyl-4-ethylene-5- pyrazolone isoniazid (PPeAP-INH) is 1D polymer bridged by the N atoms of pyrazolyl heterocycles. The binuclear Mn complexes of PM4MbP-INH and PPePeP-INH are hydrogen bonded 1D supermoleculer networks. And we discussed the influence of the different substituents in the 3 and 4 position of the pyrazolone upon the coordination mode.In the fourth part, N-(1-phenyl-3-phenmethyl-4-phenylethylene-pyrazolone- 5)-salicylidene hydrazone (PPePeP-SAH) and its metal (Zn(II), Cu(II), Co(II)) complexes have been synthesized and characterized by elemental analyses, IR spectra, single crystal X-ray diffractions and fluorescent properties. The results showing the ligands with hydrazone have sound coordination properties. They can coordinate with metals steadily and can form polynuclear complexes with transition metals.