Theoretical Study of a Conformational Change Occurring with Lithium Complexation to a Tetra-aza Macrocycle Containing 2,2′-Bipyridines
Theoretical Study of a Conformational Change Occurring with Lithium Complexation to a Tetra-aza Macrocycle Containing 2,2′-Bipyridines
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2,2-联吡啶四氮杂大环锂络合发生构象变化的理论研究
DOI：
10.1246/bcsj.74.1241
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发表时间：
2001
影响因子：
4
通讯作者：
S. Tsuchiya
中科院分区：
文献类型：
--
作者：
A. Furuhama;K. Takano;S. Ogawa;S. Tsuchiya
用从头算Hartree-Fock理论确定了含2，2‘-联吡啶的二丁基二氰基四氮杂大环(1)及其锂配合物的模型分子的结构。还研究了与锂离子络合过程密切相关的构象反转的能量分布。亚甲基碳桥上带有氰基的大环被发现是与大环相关的良好的大环模型(1)。驻点的能量分布和大环及其锂络合物的振动频率表明，锂络合后锂络合物的构象反转是可能的。与锂离子运动对应的振动频率的差异表明，大环状结构中的类C2v骨架与配位氮之间的相互作用比C2H结构更强。
Ab initio Hartree–Fock theory was used to determine the structures of model molecules of a dibutyl dicyano tetra-aza macrocycle (1) containing 2,2′-bipyridines and their lithium complexes. Energy profiles for the conformational inversion, which is closely related to the complexation process of a lithium cation, were also studied. Macrocycles having cyano groups on the bridge methylene carbons were found to be good macrocyclic models related to the macrocycle (1). The energy profiles of stationary points and the vibrational frequencies of macrocycles and their lithium complexes reveal that conformational inversion in the lithium complexes is plausible after lithium complexation. The difference in the vibrational frequencies corresponding to the movement of the lithium cation suggests that C2v-like skeletons in the macrocyclic moiety have a stronger interaction between the lithium cation and coordinating nitrogens than the C2h structure.