Synthesis,Structure And Property Research Of Complexes Based On Transition Metals And Pyrazolyl Ligands

In this thesis,three new organic ligands including two monopyrazole ligands and one bipyrazole ligand were synthesized.Moreover,the reaction of transition metal salts containing silver???,copper???,cobalt???or zinc???with those lingands afforded six complexes..These ligands and complexes were characterized by CHN microanalyses,1H NMR,powder X-ray diffraction,mass spectrometry measurements,et al.Besides,the structures of these complexes were determined by single crystal X-ray diffraction.Three organic ligands as listed:Ethy12-?3,5-dipheny1-1H-pyrazo1-4-y1?acetate?HL1?2-?3,5-dipheny1-1H-pyrazo1-4-y1?acetic acid?H₂L²?4-?2-tert-butyl-3-??3,5-dip henyl-1H-pyrazol-4-yl?methyl?benzy1?-3,5-dip heny1-1H-pyrazole?H2L³?Six complexes as follows:[Ag₄L₄¹]?1?{[Cu₂?HL²?₂Br]Br} · CH3OH?2?[Co?HL²?₂]?3?[Zn?HL²?₂]?4?[Ag₄?L³?₂]?5?[Ag6?L³?3]?6?Based on the further study and investigation of these complexes,several observations were found:1.[Ag₄L₄¹]?1?formed by the pyrazolyl ligand which 4-substituent is ethyl acetate and silver a tetranuclear complex featuring Ag₄pz₄?pz = pyrazole?cluster.As to pyrazolyl ligand which 4-substituent is acetic acid,it form the three-dimensional with transition metal Cu?II?,Co?II?and Zn?II?,and both N atoms in the pyrazolate and O atoms in the carboxylate group participate in the coordination.Thus it can be seen that the coordination ability of the ester is weak,the coordination model of the pyrazolyl ligand which 4-substituent is ester is similar to normal pyrazole.While N atoms in the pyrazolate and O atoms in the carboxylate group can both participate in the coordination in the pyrazolyl ligand which 4-substituent is carboxy,so the pyrazolyl ligand which 4-substituent is carboxy can used as a kind of dual functional ligand for the preparation of coordination polymer.2.The assembly of the ligand H₂L² and Ag?I?afforded colourless block crystals.Interestingly,when the block crystals were kept in the mother liquor for a longer time?usually two months?,the blocks gradually become needle-like crystals.After determined by X-ray diffraction,the block crystals is tetranuclear silver cluster[Ag₄?L³?₂]which structure is similar with the pyrazolyl ligand which 4-substituent is ethyl acetate and silver.The needle-like crystals is hexanuclear triangular prism cage[Ag6?L³?3].It is constituted by two Ag3pz3 clusters which are triangular facet of the trigonal bipyramid.What's more,we found that when[Ag6?L³?3]dissolved in CDCl3 and CD2Cl2,it can return to[Ag₄?L³?₂].This shows that the isomerization in bipyrazole and coinage metal chemistry is based on the isomerization of Ag3pz3 and Ag₄pz₄ in pyrazole and coinage metal chemistry.It also illustrates the similarity between bipyrazole and coinage metal chemistry and pyrazole and coinage metal chemistry.