4,4'-联-1,2,4-三唑的合成、表征和晶体结构

Synthesis,Characterization and Crystal Structure of 4,4'-Bis-1,2,4-triazole

以甲苯为溶剂,N,N-双(二甲基氨基亚甲基)肼二盐酸盐)(1),与4-氨基-1,2,4-三唑缩合制得4,4'-联-1,2,4-三唑(2,BTr),产品经1H N M R,IR,M S和元素分析确证结构,并成功培养出BT r单晶。考察了反应中溶剂、投料比、时间及温度对BT r产率的影响。结果表明,缩合反应的最佳溶剂为甲苯,最优工艺条件为n(1):n(4-氨基-1,2,4-三唑)=1:1.2,时间为8 h,温度为110℃,所得收率可达86.4%。经X射线单晶衍射仪测定,BT r单晶晶体为斜方晶系,属Pnma空间群,晶体学参数为:a=0.69712(14)nm,b=0.74045(15)nm,c=1.1156(2)nm,V=0.5759(2)nm3,Z=4,D c=1.570 g·cm-3,F(000)=280,R1=0.043,ωR2=0.1222,BT r分子中两个单三唑环在空间相互垂直,该立体结构空间位阻小,利于分子稳定。

4,4′-Bis-1,2,4-triazole（2,BTr）was synthesized from N,N-dimethylformamide azine dihyfrrochloride（1）and 4-ami-no-1,2,4-triazole in toluene as solvent. The structure of BTr was characterized by 1H NMR,IR,MS and element analysis. The single crystal of BTr was also cultivated successfully and determined by a X-ray single crystal diffractometer. The effect of reaction solvent,molar ratio,time and temperature on the yield of BTr were investigated. Results show that using toluene as reaction slov-ent,the optimal conditions of preparation are as follow：molar ratio of 1 to 4-amino-1,2,4-triazole 11. 2,time 8 h,temperature 110 ℃,the yield is 86. 4%. And the crystal of title compound is orthorhombic system,space group Pnma with crystal parameters of a=0.69712（14）nm,b=0.74045（15）nm,c=1.1156（2）nm,V=0.5759（2）nm3,Z =4,Dc =1.570 g·cm -3,F（000）=280,R1 =0. 043,ωR2 =0. 1222. The two triazole rings in BTr are vertical to each other,and that should be beneficial to the stability of the molecule due to the least steric hindrance. .