The Crystal Structures Of The Coordination Polymers Of 4-amino-1,2,4-triazole And Its Derivatives With Transitional Metal

The rational design and synthesis of functional complexes, especial coordination polymers have emerged as one of the most appealing areas of chemical research in recent years. The subject attracts attention of both foundational and applied research areas. The theoretical prediction of crystal structures and special functions remain to be very difficult due to they may be affected by many factors. How network could be formed for a given ligand and metal ion and what the relationship between molecular structures and functional are major challenges in this area. Although lots of coordination polymers which have novel structures have been synthesized by designing appropriate ligands, importing bridging ligands or changing the synthesis conditions by chemistes, the structural modulation of coordination polymers is still depending on self-assembly. In this dissertation, the influence factors governing the framework formations of the coordination polymers were discussed (e.g. bridging ligand, coordination geometry of the metal ion, counteranion and reaction condition, etc). Furthermore, luminescent properties of some coordination polymers have been studied. 4-amino-1,2,4-triazole and its derivatives were synthesized and selected to react with some transition metal ions, and ten crystals of metal complexes with 0D, 1D, 2D or 3D structures have been obtained. The main contents have been summarized as following:1. Four new 3d-3d heterometallic complexes have been synthesized by one pot reaction of Zn-M(Ⅱ) (M = Cd, Mn or Fe), NH4SCN and 4-amino-1,2,4-triazole (atrz, L1) or 3,5-dimethyl-4-amino-1,2,4-triazole (admtrz, L2). Single crystal X-ray analysis indicates that {Cd2.84Zn2.16(L1)6(SCN)10}n·4nH2O (1a), {Cd3.42Zn1.58 (L1)6(SCN)10}n·3nH2O (1b) and {Cd3.72Zn1.28(L1)6(SCN)10}n·4nH2O (1c) are three 3D framework structures, which have uniform architectures obtained in one system. Zn2.52Mn2.46(L1)8(SCN)10 (2) and Zn2.66Fe2.34(L1)8(SCN)10 (3) are two pentanuclear complexes. A mononuclear complex Zn(Mn)(L2)4(SCN)4 (4) was obtained when the ligand L2, SCN-, Zn(Ⅱ) and Mn(Ⅱ) were mixed. The structure transformation from 1D chain to 3D framework in solution was found by changing the reflux time, Structures were proved by single-crystal X-ray diffraction analysis and PXRD.2. Three novel triazole-bridged cadmium coordination polymers [Cd3(L1)4Cl6]n (5), [Cd(L2)Cl2]n (6a or 6b), [Cd(L3)Cl2]n (7) (L3 = 3,5-bis(aminomethyl)-4-amino-1,2,4-triazole, aamt) have been synthesized. 6a and 6b are two similar architectures but have different photo physical property, which were obtained by changing the temperature of reaction. Furthermore, luminescent properties of some coordination polymers have also been studied and they exhibit strong fluorescence emission bands in the solid state at ambient temperature.3. A 2D polymer [Zn(Py)(tp)]n (Py = pyridine; tp = terephthalic acid) (8) and two metal-organic frameworks (MOFs) [Zn3(C4H6N3)2(tp)3]n·nH2O (9), [Cd2(L2)(tp)2(DMF)2]n·nDMF (10) with tp or triazole bridged coordination polymers have been synthesized by solvothermal methods. They exhibit strong fluorescence emission bands in the solid state at ambient temperature.