The Research Of Magnetic Properties Of 3d-4f Mixed Metal Complexes

Coordination Chemistry is an important research field of contemporary inorganic chemistry,it is mutual penetrationed with organic chemistry,physical chemistry,biochemistry,solid chemistry,materials chemistry and environmental chemistry,it has become the intersection of many disciplines.Single-molecule magnets?SMMs?belonging to an important branch of the field of coordination chemistry,compared to conventional magnetic material,it has a feature of small size,easily processing,low power consumption and high efficiency transmission,currently,and it has porential application in magnetism information storage and quantum calculations.Due to the limitations of 3d transiton metal complexes in terms of structure and magnetic properties,people turning to study 3d-4f mixed metal complexes,due to the energy barrier and blocking temperature have improved obviously compared with transiton metal SMMs,indeed.This provides a new idea for people to design the single-molecule magnet,and also promote people to explore new synthesis method continuously.This paper describes the characteristics of single-molecule magnets,we reviewed the recent research progress of transition metal?3d?and rare earth?4f?and3d-4f mixed metal complexes,and we designed and synthesized a series of complexes with novel structure.Herein,in the process of design and synthesis 3d-4f mixed metal complex,we also synthesised some 3d-transition metal complexes,and some have good properties of SMMs,which have layed a good foundation for us to further synthesis 3d-4f mixed metal complex.The main contents are as follows.The first chapter is an introduction.Introduce the research background of coordination chemistry,properties and function of metal complex,and molecular magnets,and focuses on the research progress of single molecule magnets,including basic synthetic methods and recent exploration results in this area.The objective of the dissertation was proposed.In chapter two,even if we have added 4f rare earth salt in the reaction system,the rare metal ions didn't added to the six compounds we synthesized,we got six 3d transition metals complex,we did the single crystal structure determination,element analysis,Infra-red spectrogram representation for these complexes,and also did themagnetism test for part of the complexes and describe it in detal.The six complexes are one [Mn₆Na₄] dimer complex,one [Fe₆O₂Cl₄?hmp?₈]·Fe₂OCl₆?Hhmp = 2-?Hydroxymethyl?pyridine?complex,one [Fe₇] complex,one octahedral [Fe₆]complex,one [Ni₄] complex and one [Mn₇] complex,respectively.Magnetism research indicate that [Mn₇] complex has frequency dependence phenomenon which belongs to SMMs.In chapter three,in order to synthesis the transition-rare erath mixed metal complex,we added 3d-transition metal salt of Fe and 4f-rare earth metal salt to the solution system which has mixed ligands of di-2-Dyridyl ketone and2,6-Pyridinedimethanol,synthesized four 3d-4f mixed metal complexes[Fe₄Ln₂]?Ln = Dy?Ho?Er?Gd,the four compound is the first 3d-4f mixed metal complex which has mixed ligands at present?.The single crystal structure determination,element analysis,Infra-red spectrogram representation and magnetism test were carried out for the four complexes.since similar structural properties of four compounds,in this paper the structure of the compound [Fe₄Ho₂] was described specifically,magnetism research indicates that ac susceptibility out-of-phase??''M?of[Fe₄Dy₂] has frequency dependence phenomenon in the field of 2000 Oe which belongs to SMMs,and appears a peak,fitted by the Arrhenius formula,the effective energy barrier is 22.07 K.