Design,Synthesis And Magnetism Of Low Spin Fe~?,Mn~? Complexes

Currently,molecule magnets based on low-spin Fe^?,Mn^?are still scarce.Distilling a classic structure from the series of coordination compounds mentioned above,magnetism-structure relation quantitatively modeling base on all main data dimensions were seldom reported.This thesis would concentrate on synthesis,structures and magnetism of coordination compounds based on low-spin Fe^?,Mn^?,and magnetism-structure relation quantitatively modeling on the system of low-spin Fe^?and high-spin Mn^?bridged by cyano group.The main content of the thesis is listed below:1.Based on Fe^?L¹₂,Mn^?L¹₂,Mn^?L²₂ components,a series of trinuclear,chainlike alternate low-spin and high-spin structure were obtained,while all of the complexes were antiferromagnetic.As a result,a syn-anti mode carboxylate bridge group would like to transfer antiferromagnetic coupling.All three chainlike complexes didn't give any SCM behavior,which indicated antiferromagnetic made against construction of SCM.Another ligand was used to build a Mn^?dinuclear complex bridged by acid amide from the ligand.Unfortunately,the ligand could not stable low-spin state of Mn^?,while the acid amide was still apt to transfer antiferromagnetic coupling.2.An alternate low-spin and high-spin Mn^?single chain bridged by cyano group was synthesized by controlling the environment of solvent.Magnetic analysis indicated the single chain structure behaved as an SCM,while an energy barrier was found higher than average of the ones reported before.A double relaxation processes also existed.The complex was reported as the first straight SCM with alternate low-spin and high-spin Mn^?.Meanwhile,a series of low-spin Fe^?and NiIIchain were synthesized based on [Fe?im??CN?5]2-and[Ni?L?]2+.Structural factors of magnetism based on this series were discussed in this part.3.In order to construct a effective magnetostructural correlation quantitatively modeling base on the system of low-spin Fe^?and high-spin Mn^?bridged by cyano group,structural data of 23 complexes reported were collected and sorted,bond index of the system was calculated by DFT methods,multiple linear regression was applied as main statistical mean.As a result,new quantitative model was developed to explain about 49.3% of the magnetic coupling constant's change.