2-氯甲基苯并咪唑硝酸盐的晶体结构、质子化特征及量子化学理论研究

2-Chloromethyl-3H-benzoimidazol-1-ium Nitrate: Crystal Structure, Protonation Character and Quantum Chemical Study

制备了 2 氯甲基苯并咪唑硝酸盐 (C8H8N2 Cl+ ·NO-3 )化合物 ,采用元素分析 ,IR ,1HNMR和TG DTA对产物进行了表征 ,并采用X射线单晶衍射仪测定了该化合物的晶体结构 ,该化合物属单斜晶系 ,空间群P2 1/n ,a =0 .74189(3 )nm ,b =1.5 3 0 64 (6)nm ,c =1.0 5 478(3 )nm ,β =12 0 .93 0 (2 )° ,V =1.0 2 744nm3 ,Dc=1.484g/cm3 ,Z =4,F(0 0 0 ) =472 ,μ =0 .3 63mm-1,R =0 0 65 9,wR =0 .14 98,GOF =0 .840 .在此基础上 ,采用量子化学方法 ,在MP2 /6 3 11G ,B3LYP/6 3 11G 和HF/6 3 11G 水平上计算了 2 氯甲基苯并咪唑及其质子化阳离子的优化构型、电荷分布、振动光谱、热力学函数及总能量 .计算结果显示 2 氯甲基苯并咪唑环具有较强质子化能力 。

Chloromethyl-3H-benzoimidazol-1-ium nitrate was synthesized and characterized by elemental analysis, IR, 1H NMR and TG/DTA. Its single crystals were determined by X-ray single crystal diffraction. The compound belongs to monoclinic system with space group P2 1/n, a=0.74189(3) nm, b=1.53064(6) nm, c=0.92657(3) nm, β= 102.449(2)°, V=1.02744 nm 3, D c=1.484 g/cm 3, Z=4, F(000)=472, μ=0.363 mm -1, R=0.0671, wR=0.1546, GOF=0.854. Furthermore, the optimized geometry, charge distribution, vibration spectra and molecular total energy of 2-chloromethyl-benzoimidazol and 2-chloromethyl-3H-benzoimidazol-1-ium cation were obtained by quantum chemical method at the MP2/6-311G **, B3LYP/6-311G ** and HF/6-311G ** levels. The calculated results reveal that the title compound has a strong proton affinity, which is consistent with the result from single crystal structure.