异质同晶体——三(2—苯并咪唑亚甲基)胺合钴(Ⅱ)和锌(Ⅱ)配合物的合成、结构及量化计算

Synthesis, Structure and Quantum Calculation of the Isomorphor——Tris(2-benzimidazolylmethyl)amine Cobalt(Ⅱ)and Zinc(Ⅱ) Complexes

合成了三(2-苯并咪唑亚甲基)胺合钴(Ⅱ)(化合物a)和三(2-苯并咪唑亚甲基)胺合锌(Ⅱ)(化合物b)配合物,进行了元素分析和红外光谱表征;用单晶X射线衍射方法测定了它们的晶体结构.测定结果表明化合物a和b是一对异质同晶体,配合过程中NTB的两个N原子被去质子化,晶体属立方晶系,I-43d空间群.晶胞参数a=b=c=2.2353(3)nm,V=11.169nm^3,Z=16,最终偏离因子为R_1=0.0686(a)和0.0688(b).配合物中的金属原子与配体NTB分子中的一个烷胺氮原子、三个sp^2氮原子和一个水分子中的氧形成五配位的扭曲三角双锥构型.用密度泛函的方法进行了量子化学计算,结果表明NTB分子有去质子化的倾向,与配合物晶体结构测定结果(配合物中配体以NTB^(2-)形式存在)相吻合.

Tris(2 - benzimidazoly]methyl)amine cobalt (Ⅱ) (complex a) and tris(2 - benzimidazolylmethyl) amine zinc (Ⅱ)(complex b) were synthesized. Their crystal structures were determined by X - ray method. Elemental analysis and IR spectra of the two title compounds were performed. The results show that complexes a and b are a pair of isomorphors. During the formation of the complexes, the two N - atoms of NTB were unprotonated . The crystals are cubic , I - 43d space group , with a = b = c = 2.2353(3)nm, V = 11.169nm3, Z = 16. The final refinement converged to R = 0.0686 (a) and 0.0688(b). In the two complexes, the metal atom is coordinated with one nitrogen atom of alkylamine and three sp2 nitrogen atoms from NTB and one oxygen atom from H2 O to form a distorted trigonal - bipyramid configuration. The quantum calculation was performed by the method of density function. The results show that the NTB molecule tends to be unprotonted, which is consistent with that of the crystal structure.