Synthesis, Crystal Structures And Characterization Of The Complexes With 3-methyl-4-Ethyl-5-Pyridyl- 1,2,4-triazoles

1,2,4-Triazoles and their derivatives have special structures and properties of heterocyclic compounds. They have been widely used in pharmaceuticals, agricultural chemicals, synthetic chemistry and industry fields. As a continuation of our investigation of complexes with 1,2,4-triazoles, we have synthesized four new 1,2,4-triazole compounds and six transition-metal complexes. The single crystal structures of complexes were also determined. This thesis is composed of following sections.1. Four novel compounds of 3-methyl-4-ethyl-5-（2-pyridyl）-1,2,4-triazole, 3-methyl-4-ethyl-5-（3-pyridyl）-1,2,4-triazole,3-methyl-4-ethyl-5-（4-pyridyl）-1,2,4-triazole and 3-methyl-4-ethyl-5-（o-hydroxyphenyl）-1,2,4-triazole were synthesized from picolinic acids and salicylic acid, and their structures were confirmed by NMR and IR. The single crystal structure of 3-methyl-4-ethyl-5-（4-pyridyl）-1,2,4-triazole was determined by X-ray analysis.2. Six new complexes of trans[-CuL₂（H₂O）₂[ClO₄)₂、trans-[NiL₂（NO₃）₂]-[Cu₂（μ-L）₂Cl₄]·4H₂O、[Mn₃（μ-L）₂（μ-Cl）₂Cl₄（H₂O）₂]、[Ag₂（μ-L）₂L₂（NO₃）₂] and [Ag₂（μ-L’）₂（H₂O）₂]n（NO₃）_2n were prepared from the ligands of 3-methyl-4-ethyl-5-（2-pyridyl）-1,2,4-triazole （L） and 3-methyl-4-ethyl-5-（2-pyridyl）-1,2,4-triazole （L’）, and their single crystal structures were determined by X-ray analysis.Both the complexes of trans-[CuL₂（H₂0）₂]（C104）₂ and trans[NiL₂（NO₃）₂] are mononuclear complexes. The centre Cu（Ⅱ） and Ni（Ⅱ） atoms have distorted octahedral geometries with MN₄O₂.The complexes of [Cu₂（μ-L）₂Cl₄]-4H₂O and [Ag₂（μ）₂L₂（NO₃）₂] are binuclear complexes bridged by the nitrogen atoms （N₁ and N₂） of the 1,2,4-triazole ring in L ligands. The centre Cu（Ⅱ） atoms have distorted trigonal-bipyramidal geometries with CuCl₂N₃, and the centre Ag（Ⅰ） atoms possess distorted tetrahedral geometries with AgN₃O.The complex of [Mn（μ-L）₂（μ-Cl）₂Cl₄（H-2O）₂] is a trinuclear Mn（Ⅲ） complex bridged by the L ligands and chloride atoms. The Mnl（Ⅱ） atoms have centrosymmetric distorted octahedral geometries with MnCl₂N₂O₂. and the Mn₂（Ⅱ） atoms have distorted trigonal-bipyramidal or tetragonal-pyramidal geometries with MnCl₃N₂.The complex of [Ag₂（μL’）₂（H₂O）₂]n（NO₃）_2n is a polymer-complex bridged by the L’ ligands. Every repeat unit have two Ag（I） atoms, and the central Ag（Ⅰ） atoms have distorted tetrahedral geometries with AgN₃O.3. The complexes of [Cu₂Gu-L)₂Cl₄]·4H₂O、trans-[CuL₂（H₂O）₂]（ClO₄）₂ ] and [Ag₂（μ-L’）₂（H₂O）2]_n（NO₃）_2n have been characterized by IR, UV/Vis, fluorescence measurement and thermogravimetric analysis.