N,N′-二羧基苯并咪唑内鎓盐的合成、晶体结构、荧光性质和解离平衡常数研究

Synthesis,Crystal Structure, Fluorescenct Property and Dissociation Equilibrium Constant of 1-(carboxymethyl)-1,3-benzimidazol-3-ium-3-acetate

以苯并咪唑为原料,合成了两性羧酸N,N′-二羧甲基苯并咪唑内鎓盐(1)。在Al(OH)3存在条件下通过水热法获得化合物(1)的新型单晶。通过X-射线单晶衍射法确定了其结构,荧光光谱法研究了其荧光性质,并用电位滴定法测得25℃时其解离平衡常数Ka为2.26×10-4。标题化合物属正交晶系,I41/a空间群,Mr=522.47,a=18.3086(9),b=18.3086(9),c=14.1915(14),z=8,Dc=1.422mg·m-3,F(000)=2192,最终偏离因子R=0.0578,wR2=0.1799。

The title compound 1-（carboxymethyl）-1,3-benzimidazol-3-ium-3-acetate （1） were synthesized from benzimidazole and chloroacetic acid. Single crystals of （1） was obtained in existence of Al（OH）3by hydrothermal method. Its structure was determines by X-ray diffraction method. Its spectral properties and the equilibrium dissociation constant （Ka） were studied by fluorescence spectra and potentiometric titration, respectively. Compound （1） belongs to orthorhombic crystal system, I41/a space group,Mr =522.47,a = 18. 308 6（9） ,b = 18. 308 6（9） ,c =14. 191 5（14）, z =8, Dc =1.422 mg·m^-3, F（000） =2 192, the final deviation factor R =0.057 8, ωR2 =0. 179 9.