Synthesis,Structure And Performance Characterization Of Rare Earth And Ni(?)/Cu(?) Complexes Based On Schiff Base Ligands

Schiff base complexes are concerned because of its potential application value in medical,analytical chemistry,catalysis,photochromic and molecular magnetic materials.Especially in the research of Single molecule magnet meterials,it plays a vital role in today's information age.Due to the special group–C=N-from Schiff base ligand,which makes it easy to form Schiff base complexes with special structure and provides convenient to build more novel Single molecule magenet.Four new Rare earth complexes base on Schiff base ligand,namely LnL¹₂?L¹=6,6'-??1E,1'E?-?ethane-1,2-diylbis?azanylylidene??bis?methanylylidene??bis?2-methox yphenol?,Ln=Tb?1?,Dy?2?,Ho?3?,Er?4??have been synthesized by solvent evaporation and characterized by Single crystal X-ray diffractions,IR,UV,TGA and magnetic.Single crystal X-ray diffraction reveal that both 1-4 crystallize in the same monoclinic space group C₂,1-4 are eight-coordinated.TGA shows that complexes 1-4can be stable to 205?.Magnet studies reveal that complexes 1,2,4 have shown single-molecule magnet behavior at 2KOe.Moreover,the resistive component of ac susceptibility curve of 4 show frequency dependent peak at the temperature of 2-4K,and the inscriber of curve don't overlap obviously,exhibits slow relaxation behavior.Four new transition metal complexes namely Ni₂L₂²?5?,CuL₂²·CH₃OH?6??L²=?E?-3-?4-mercaptobut-1-en-1-yl?benzene-1,2-diol?,and Ni₃L₃³·CH₃OH·H₂O?7?,CuL₂³?8??L³=?E?-2-?4-mercaptobut-1-en-1-yl?-6-methoxyphenol?havebeen synthesized by solvent evaporation based on Schiff base ligand and characterized.Single crystal X-ray diffraction reveals that 5 crystallizes in monoclinic space group P2?1?and is dinuclear complex,6 crystallizes in monoclinic space group P2?1?also and is mononuclear complex,7 crystallizes in monoclinic space group C₂ and is trinuclear complex,8 crystallizes in triclinic space group p-1 and is mononuclear complex,both 5-8 are four-coordinated.But the coordination environment of the four complexes is different,compare to the formation of S-Ni bond in two Ni complexes,the S-S bond instead of S-Cu bond is formed in two Cu complexes.Complexes 5-8show fluorescent emission at 413,417,412,415nm,respectively.The fluorescence properties of 5-8 are due to electronic transitions from Schiff base ligand itself.The dc magnetic susceptibility curves of complexes 5 and 7 reveal the diamagnetic behavior.The ring-opening reaction of epoxy cyclohexane has been tried by using complex 5-8as catalyst,the results show 6 and 7 have certain catalytic effect,while 5 and 8 don't have.