Synthesis,Structure And Properties Of Complexes Of Transition Metals Based On 3-Amino-5-Carboxy-1,2,4-Triazole And Aminopyrimidine Derivatives

In recent years,with the cross-infiltration and blending of various disciplines,coordination chemistry has developed rapidly,showing a changing landscape,and has begun to advance toward functional coordination compounds.Self-assembled crystal engineering studies of transition metals and triazole ligands have engrossed the attention of more and more chemists.Under the influence of this background,many complexes formed by covalent bonds,hydrogen bonds,?-?stacking,and other forces have also been reported.Since the first in-situ reaction in solvothermal conditions has emerged,solvothermal methods,one of the complex synthesis methods,have also been sought after by many scientists.This type of reaction has been used successively for the synthesis of novel coordination compounds,the discovery of new organic reactions,and the elaboration of reaction mechanisms.This thesis mainly studies the synthesis and reaction mechanism of triazole derivatives and aminopyrimidine complexes.Part I:mainly summarizes the research progress of triazole ligands and their salicylaldehyde Schiff bases and the research progress of aminopyrimidine complexes.Part II:Research papers,including the synthesis,structure,and properties of triazole Schiff bases and carboxylate ligands and 2-aminopyrimidine ligands and their complexes.The details are as follows:1.Two Schiff base ligands were synthesized from 3-amino-5-carboxy-1,2,4-triazole:s alicylaldehyde-3-amino-5-carboxy-1,2,4-Triazole Schiff base(HL¹),methoxy salicylaldehy de-3-amino-5-carboxy-1,2,4-triazole Schiff base(HL²).Studies have shown that both Schif f bases have undergone decarboxylation.The above Schiff base is reacted with Cu(I)und er solvothermal conditions to obtain eight unreported compounds,wherein(1)-(7)are Cu(I)complexes,and(7a)is a pure ligand,not coordinated with Cu(I).Their chemical for mulas are:(1)[Cu(L^1a)₂Cl],(2)[Cu(L^1a)₂Br],(3)[Cu(L^2a)₂Cl],(4)[Cu(L^2a)₂Br],(5)[Cu(L^1b)₂Cl],(6)[Cu(L^1b)₂Br],(7)[Cu(L^2b)₂Cl],(7a)C₁₄H₁₆N₄O₂(L^2b).The structures of these c ompounds were determined by single crystal diffraction and characterized by infrared and powder diffraction,and the biological activities and thermal stability of the complexes(1)-(7)were also studied.It was found that during the synthesis of the above compounds,two Schiff base ligands(HL¹and HL²)reacted in situ with the solvent acetone and 2-b utanone to form new compounds.The influencing factors and reaction mechanism of the in-situ reaction were also discussed.2.3-Amino-1,2,4-triazole-5-carboxylic acid ethyl ester(L³)was synthesized from 3-a mino-5-carboxy-1,2,4-triazole.Two novel complexes were synthesized under hydrothermal conditions,(8)[Mn₂(L³)₂(CH₃CN)₂Cl₄],(9)[Ni(L³)₂Cl₂].Their structures were determined by single crystal diffraction.The single crystal structure showed that the complexes(9)a nd(10)were monoclinic,and the central metal ions were coordinated with the ligand in a six-coordinate mode.The two complexes were characterized by infrared,thermal analy sis and powder diffraction.3.Using 2-aminopyrimidine and salicylaldehyde(hereinafter referred to as Sal)as ra w materials,under hydrothermal conditions,three kinds of nitrates reacted with metals C o(II),Ni(II)and Zn(II)to obtain three No reported complexes(10)[Co₂(Sal)₂(2-NH₂pym)]_n,(11)[Ni₂(Sal)₂(2-NH₂pym)]_n,(12)[Zn(L⁴)₂],their structures were determined by single cr ystal diffraction,and the single crystal structure showed that the complexes(10)and(11)were heterogeneous and all belong to the one-dimensional chain polymerization of the tr iclinic system.The central metal ion adopts a six-coordinate mode,and the mode of the central metal ion is a slightly distorted octahedral configuration due to the difference in the bond length of the bond when coordinating with the ligand.The complex(13)belo ngs to the monoclinic system.The ligand 2-aminopyrimidine reacts with salicylaldehyde t o form the corresponding Schiff base and then reacts with the metal salt Zn(NO₃)₂·6H₂O,and its thermal stability.In-depth research has been carried out on electrochemical catal ysis and magnetism.The results showed that although the compounds(1)-(7a)were simil ar in structure,the biological activities were very different;the complexes(10)and(11)exhibited antiferromagnetic interactions and none of the single-molecule magnets.