Zero-Field Splitting of the Lowest Excited Triplet States of C60 and C70 and Benzene
Zero-Field Splitting of the Lowest Excited Triplet States of C60 and C70 and Benzene
复制标题
C60 和 C70 与苯最低激发三重态的零场分裂
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Gastel
中科院分区：
文献类型：
--
作者：
M. Gastel
C60和C70的最低激发三重态的电子结构的特征在于未成对电子之间的磁相互作用，其中零场分裂参数D对于前者为负，对于后者为正。到目前为止，D的符号已经被定性地理解，并且它的大小被发现严重依赖于单占据分子轨道的离域程度。在这方面的贡献，自旋极化的零场分裂参数的富勒烯的效果进行评估，包括其中的结果在定量的实验和计算的D值之间的协议。直接自旋-自旋的贡献被发现是占主导地位的两个分子。对于C60，已经发现总零场分裂的20%的显著贡献来自自旋极化。并将C_（60）和C_（70）的D符号不同的物理原因归结为相邻两个分子的局域pz轨道的相对相位。
The electronic structure of the lowest excited triplet states of C60 and C70 are characterized by a magnetic interaction between the unpaired electrons for which the zero-field-splitting parameter D is negative for the former and positive for the latter molecule. The sign of D has so far been qualitatively understood, and its magnitude has been found to critically depend on the degree of delocalization of the singly occupied molecular orbitals. In this contribution, the effect of spin polarization to the zero-field-splitting parameters of the fullerenes is evaluated, the inclusion of which results in quantitative agreement between the experimental and calculated D values. The direct spin−spin contribution is found to be dominant for both molecules. For C60, a significant contribution of 20% of the total zero-field splitting has been found to derive from spin polarization. The physical reason for the sign difference of D for C60 and C70 is traced back to the relative phases of the local pz orbitals of adja...