Synthesis,Structures And Properties Of Metal Coordination Polymers Based On 2-Thiobarbituric Acid

2-Thiobarbituric acid is a nitrogen-containing heterocyclic compound with a wide range of physiological activities.The nitrogen-containing heterocyclic compounds have strong coordination ability.It has been found that 2-thiobarbituric acid ligand which contains N,S,O atoms is good multi-dentate ligand and often exhibits interesting chemical,biochemical and optical properties as well as diverse structure,so people are increasingly interested in its research.In this study,2-thiobarbituric acid was used as an organic ligand and assembled with appropriate transition metal ions and rare earth metal ions.A series of coordination polymers with different structure types were synthesized and characterized by elemental analysis,spectroscopic analysis and X-ray single crystal diffraction.The thermal stability,fluorescence and magnetic properties of the coordination polymers were also studied.The main contents are as follows:Firstly,2-thiobarbituric acid was used as an organic ligand,and three coordination polymers were obtained by the diffusion method or solvothermal method with transition metal ions?Fe/Co?,namely {[Fe?H₂TBA?₂?H₂O?₂].2DMF}n?1?,[Co?H₂TBA?₂?DMF?₂]n?2?,{[Co?H₂TBA?₂?H₂O?₂].2DMF]}n?3?.And the structures and properties were tested by various spectral characterization methods.The results show that the coordination polymers 1 and 3 are three-dimensional structures and the same configuration.The coordination polymers 2 is two-dimensional structure.With respect to the thermal stability,the coordination polymers 1 and 2can reach 200 ?.The coordination polymer 1 has ferromagnetic interaction.At the excitation wavelength of 273 nm,the coordination polymer 2 has strong emission peak at 477 nm and 489 nm.Secondly,2-thiobarbituric acid was used as an organic ligand,and five coordi-nation polymers were obtained by the diffusion reaction with rare earth metal ions,namely {[Sc?H₂TBA?₃?DMF?].2DMF}n?4?,{[M?H₂TBA?₄?DMF?₄?H₂O?][M?TBAS-STBA?₂?DMF?₄]?H₂O}n?M=Pr?5?,Nd?6?,Gd?7?,Ce?8??.And the structure and properties was tested by various spectral characterization methods.The results show that the coordination polymers 4 is two-dimensional structures,coordination polymers 5-8 are three-dimensional structures.The coo-rdination polymer 4 has a certain thermal stability.The coordination polymers 5-8 are composed of two structural units,all of which are of the same configuration.One of the coordination unit's 2-thiobarbituric acid ligand has a coupled reaction to form a dimer and coordinate with the rare earth metal ions.