Heterodimerization via the Covalent Bonding of Ta@Si16 Nanoclusters and C60 Molecules
Heterodimerization via the Covalent Bonding of Ta@Si16 Nanoclusters and C60 Molecules
复制标题
Ta@Si16 纳米团簇与 C60 分子共价键合的异二聚化
DOI：
10.1021/jp511157n
复制
发表时间：
2015
影响因子：
3.7
通讯作者：
A. Nakajima
中科院分区：
文献类型：
--
作者：
M. Nakaya;T. Iwasa;H. Tsunoyama;T. Eguchi;A. Nakajima
用扫描隧道显微镜(STM)研究了Ta原子包裹的Si16笼(Ta@Si16)纳米团簇在C60分子单层膜封端的固体表面固载的初始产物。扫描电子显微镜结果表明，表面固定的Ta@Si16纳米团簇即使在∼500K热处理后也没有发生明显的聚集和脱附，但Ta@Si16纳米团簇相对于C60薄膜中相邻吸附中心的局部垂直和横向位置发生了改变。这种局域位置转变发生在与高取向热解石墨(HOPG)等衬底弱结合(通过范德华作用力)的C60单层膜上，而在共价结合在Si(111)7×7等衬底上的C60单层膜上则没有发生这种局域位置转变。这些结果表明，由Ta@Si16纳米团簇和C60分子组成的杂二聚体是通过共价键形成的，它抑制了宽范围的热解石墨(HOPG)的形成。
Initial products prepared via the surface immobilization of Ta-atom-encapsulated Si16 cage (Ta@Si16) nanoclusters on solid surfaces terminated with monolayer films of C60 molecules were investigated using scanning tunneling microscopy (STM). The STM results indicated that marked aggregation and desorption of surface-immobilized Ta@Si16 nanoclusters were not induced, even after thermal annealing at ∼500 K, whereas the local vertical and lateral positions of the Ta@Si16 nanoclusters with respect to neighboring adsorption sites in the C60 film were modified. This local positional transition occurred on C60 monolayer films weakly bonded (via van der Waals forces) to substrates such as highly oriented pyrolytic graphite (HOPG) but did not occur on C60 monolayer films covalently bonded to substrates such as Si(111)7 × 7. These results indicated that the heterodimer consisting of a Ta@Si16 nanocluster and a C60 molecule, Ta@Si16–C60, was formed as an initial product via covalent bonding, which inhibited wide-ran...