Theoretical study on the tetranuclear endohedral vanadyl carboxylates with guest-switchable redox properties and large polarizability.
Theoretical study on the tetranuclear endohedral vanadyl carboxylates with guest-switchable redox properties and large polarizability.
复制标题
DOI：
10.1039/b922876d
复制
发表时间：
2010-03
影响因子：
4
通讯作者：
Ping Song;W. Guan;Likai Yan;Chun-Guan Liu;Chan Yao;Zhongmin Su
中科院分区：
文献类型：
--
作者：
Ping Song;W. Guan;Likai Yan;Chun-Guan Liu;Chan Yao;Zhongmin Su
利用密度泛函理论（DFT）研究了四核氧化钒羧酸盐的极化性能和氧化还原性能。这些所谓的无机冠醚具有很大的极化能力，相当于富勒烯，并在进入宿主的客体阴离子上产生很大的极化。寄主阴离子与客体阴离子之间的偶极相互作用诱导客体向寄主转移电荷，这种转移随着极化的增加而增强。此外，氧化还原电位对宿主碗内不同的客体敏感，与孤立的宿主碗相比，它们呈负向移动。相比之下，在碗的边缘被CH(2)tBu修饰的甲基引起了更高的极化率（超过560 a.u.），在客体阴离子上有更大的极化和更多的负氧化还原电位。与加入碱金属离子的有机冠醚相一致的弱相互作用能表明，客体阴离子可以在宿主碗内外自由移动，因此这种无机冠醚可能表现出基于可逆络合解合的潜在客体切换氧化还原特性，并有望在基于对不同客体敏感性的离子识别和选择性研究中得到应用。
The polarizability and redox properties for the tetranuclear vanadium-oxide-carboxylates have been investigated using density functional theory (DFT). These so-called inorganic crown ethers possess large polarizabilities, which are equivalent to fullerene and generate large polarization on the guest anions into the host. The dipole-induced dipole interaction between the host and the guest anions induces charge transfer from the guest to the host, which is enhanced with the increasing polarization. Moreover, the redox potentials are sensitive to different guests inside the host bowl, and they shift negatively as compared to the isolated host bowl. In contrast, the modification of the methyl group by CH(2)tBu on the rim of the bowl has evoked higher polarizability (over 560 a.u.) with larger polarization on the guest anions and more negative redox potentials. The weak interaction energies in accord with the organic crown ether incorporating alkali metal ions indicate that the guest anions can move freely inside and outside the host bowl, so this kind of inorganic crown ether may exhibit potential guest-switchable redox properties based on reversible complexation-decomplexation and will be expected to find applications in ion recognition and selectivity studies based on the sensitivity to different guests.