富勒烯C_(60)硫桥键联四硫富瓦烯衍生物的理论研究

Theoretical Study of the [60]Fullerene Sulfur-bridge Covalent Bond Linked Tetrathiafulvalene Derivatives

利用半经验AM1法研究了富勒烯C60 硫桥键联四硫富瓦烯衍生物和富勒烯C60 键联四硫富瓦烯衍生物的几何构型 ,电子结构 .计算结果显示 ,富勒烯C60 硫桥键联四硫富瓦烯衍生物的四硫富瓦烯 (TTF)平面与C60 发生作用 ,使其弯曲的程度比富勒烯C60 键联四硫富瓦烯衍生物的大 ,从而形成一种独特的四硫富瓦烯 (TTF)平面半包裹C60 的空间构型的D A体系 .这很可能是由于C—S单键的灵活性造成的 .而且它们的HOMO轨道主要分布在四硫富瓦烯 (TTF)部分 ,而LUMO轨道则主要分布在C60 上 .预测了富勒烯C60

The geometry aid electronic structure of [60] fullerene sulfur-bridge covalent bond linked tetrathiafulvalene derivatives and [60] fullerene covalent bond linked tetrathiafulvalene derivatives have been calculated by AM1 method. The geometry conformation indicates that C-60 has been half-packed by the curved TTF (tetrathiafulvalene) derivatives. Their electronic structures point out that they belong to D-A systems. Their special conformations are probably determined by the flexible C-S bond. It is found that the electron clouds on unoccupied frontier orbitals mainly come from the contribution of C-60 moiety, which means that C-60 moiety can still accept electrons, while the electron clouds on occupied frontier orbitals mainly concentrate on the TTF addend. A long lived charge-separation states may occur in the [60]fullerene sulfur-bridge covalent bond linked tetrathiafulvalene derivatives when it is excited.