Synthesis And Performance Studies Of4-acylpyrazolone Ligands And Their Complexes

Studies of sythesis, properties and the effect between ligands and ions of newacylpyrazolones ligands and their complexes are becoming hot spots in the developmentof the coordination chemistry,due to the fact that are widely used in functional materials,solvent extractions of metal ions and antibacterial reagents. Literature reviews showmany heterocyclic derivatives about1-phenyl-3-methyl-pyrazolone-5(PMP) compoundbut few about long chain fatty hydrocarbon replacing4-acylpyrazolone. Therefore, inthis paper,4-heptylpyrazolone and4-caprylpyrazolone were designed and synthesisedwith the precursor of PMP. Complexes were prepared by reacting pyrazolone and theirderivatives with transition metal salts. All the compounds were studied by performancetesting and structure characterization.Seven acylpyrazolones and their deriveateives,1-phenyl-3-methyl-4-heptylpyrazo-lone (HL)，(Z)-4-(aniline)1-phenyl-3-methyl-4-heptylpyrazolone (HL1),(Z)-4-(ptoluidi-ne)1-phenyl-3-methyl-4-heptylpyrazolone(HL2),1-phenyl-3-methyl-4-caprylpyrazolone(HQ),(Z)-4-(p-toluidine)1-phenyl-3-methyl-4-caprylpyrazolone（HQ1）,(Z)-4-(thiof-uran)(phenyl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-on（HQ2）and (Z)-4-((2-chlorophenylamino)(phenyl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one(HQ3) have been sythesised. Nineteen transition complexes were sythesised by thereaction of metal salts with seven acylpyrazolones and their deriveateives in nonaqu-eous solvents. The compositions and structures have been characterized by element ana-lysis, infrared absorption spectrometry, ultraviolet absorption spectrometry, thermal ana-lysis and X-ray single crystal diffraction(XRD).In moderate conditions, all of the ligands and complexes are stable. Eleven single c-rystals of products have been accessed through the method of volatile solvent. The unitcell parameter and information of space point group were ascertained by single crystalXRD.The results of XRD data showed that the oxygen atom of carbony and nitrogenatom of derivatives coordinated to the metal ions in the complexes.Water moleculeswere coordinated to the complexes, such as Co(L)2·(H2O)2, Zn(L)2·(H2O). N,N-dimeth-yl formamide(DMF) as solvent cultivation of single crystal was also involved in coordi- nation, such as Ni(Q)2(DMF)2. Most of single crystals of products are monoclinic andtriclinic crystal system.The complex and ligand were individually tested against pathogenic bacteria suchas escherichia coli, bacillus subtilis and staphylococcus epidermidis. Antibacterialactivities of the ligand and metal complex were detected by using the disc diffusionmethod.The screened strains for some selective inhibition and have broad spectrumactivity of the complexes.Bacteriostatic order is follows: e. coli: ZnL2> CuL2> NiL2>ZnL22> CoL22; Bacillus subtilis: MnL12> NiL12> BaL2> ZnL2> ZnL22> BaL12>CoL12> CuL2; Staphylococcus aureus: CuL2> NiL2> CuL22> ZnL2> BaL2>MnL2.The results also show that bacteriostatic activities of compounds were positivelycorrelated with their concentration and the activities of the complexes is generallyhigher than the corresponding ligands.Electrochemical analysis method was used in this paper to test the electrochemicalproperties of the products. SnL2complexing adsorption wave was sensitive withconcentration change of Sn(II), which is expected to a useful electrochemical method forthe quantitative determination of tin. Electrochemical behavior of HL-Sn (II) system wastested as complexing adsorption wave. The best pH of system is4.0; The peak currenthas a linear relation with concentration of Sn (II) in electrode process and the linearequation is: Ip=0.2615+0.2635c,(0.002~0.005mol/mL) r=0.9986; Ip=0.1763+0.2345c (0.005~0.007mol/mL) r=0.9995; the stability constant of complexes is4.05x10~7.