Synthesis,Structure And Properties Of Tartaric Acid Ligand Cluster

Polyoxometalates（POMs）are nanoclusters composed of metal-oxygen frameworks.Metal ions are usually in a highly oxidized state.They have a great deal of structural versatility and have many applications in the fields of galvanochemistry,magnetism,materials science,medicine,electrochemistry,imaging technology,optical and luminescent properties etc.High-core 3d and 3d-4f metal clusters have always been the focus of attention because they represent a good system of classical phenomena.However,the formation of various metal clusters is sensitive and often depends on many reaction parameters,such as p H,temperature,molar ratio of precursor,concentration,reaction time,etc.Therefore,there are still challenges for the synthesis of high-core 3d and 3d-4f metal clusters.Our group has been working on the synthesis of high nuclear metal oxygen clusters.Based on this,we used tartrate anion ligands with pure oxygen atom as coordination atom to synthesize high core 3d and 3d-4f metal clusters.The research contents of this paper are as follows:（1）Based on our previous research on Cu-Ln clusters,two chiral clusters{L-Cu₂₂^IISm₄^ⅢK}and{L-Cu₂₂^IISm₄^ⅢK}were synthesized by one-pot method using chiral tartrate as ligand and some basic characterizations were carried out X-ray single crystal diffraction（XRD）was used to investigate the structure of these two clusters.It was found that both of them crystallized in the I432 space group,and they were a series of heterogeneous and isomorphic clusters with the Cu-Ln heteronuclear 3d-4f clusters synthesized by our research group.The results of solid and liquid circular dichromatography show that the chirality of the clusters and the chiral peak is not entirely from the tartaric acid ligand.At the same time,the performance of{Cu₂₂^IILn₄^ⅢK}whole system is explored,we found that tartrate ligands can selectively crystallize specific early rare earth ions under these conditions to achieve the effect of rare earth separation.In the reaction system where multiple rare earth ions coexist,rare earth with small ion radius is easier to coordinate to form clusters Therefore,six binary lanthanide separation experiments（La/Eu,Nd/Eu,La/Dy,Ce/Dy,Nd/Dy and Pr/Dy）were designed,and the separation factor（SF）values were calculated from the ICP test results between 22.0 and 174.Therefore,these molecular rings and the selective crystallization of early lanthanides show great potential for lanthanide separation.（2）In the buffer solution of acetic acid and potassium acetate,the metal cluster{Mn₂₁}was constructed with the introduction of guanidine phosphate as template and tartrate as ligand.It is found that guanidine phosphate plays a very important role in the synthesis process.On the one hand,the phosphate anion plays an anion induction role;On the other hand,it also acts as a ligand to coordinate with metal ions.Fourier transform infrared spectroscopy,thermogravimetric and other basic characterization and magnetic properties of the manganese cluster were studied...