Fraternal twins: distinction between PbPc and SnPc by their switching behaviour in a scanning tunnelling microscope
Fraternal twins: distinction between PbPc and SnPc by their switching behaviour in a scanning tunnelling microscope
复制标题
DOI：
10.1088/1361-648x/aafeae
复制
发表时间：
2019-04-03
影响因子：
2.7
通讯作者：
Fritz, Torsten
中科院分区：
文献类型：
--
作者：
Forker, Roman;Gruenewald, Marco;Fritz, Torsten
在这篇文章中，我们比较了铅（II）-酞菁（PbPc）和锡（II）-酞菁（SnPc）薄膜的光学吸收行为和结构特性。为此，我们采用以单层3,4,9,10-苝四甲酸二酐封端的Ag(1 1 1)基底，构成内部界面，其主要作用是酞菁吸附层与金属表面的电子去耦。根据低能电子衍射和扫描隧道显微镜 (STM) 测量得出的结论，流行的 PbPc 单层和多层域的外延关系和晶胞组成与 PTCDA/Ag(1 1 1) 上的 SnPc 非常相似。然而，SnPc 和 PbPc 可以通过其 STM 诱导的转换行为轻松区分：虽然前者能够发生可逆的构型变化，但在可比条件下我们无法对后者产生任何影响。这证实了早期的理论预测，甚至使得单个羽毛球状金属酞菁的化学鉴定变得可行。
In this contribution, we compare the optical absorbance behaviour and the structural properties of lead(II)-phthalocyanine (PbPc) and tin(II)-phthalocyanine (SnPc) thin films. To this end, we employ a Ag(1 1 1) substrate terminated with a monolayer of 3,4,9,10-perylene tetracarboxylic dianhydride constituting an internal interface whose main effect is an electronic decoupling of the phthalocyanine adlayer from the metal surface. As deduced from low-energy electron diffraction and scanning tunnelling microscopy (STM) measurements, the epitaxial relations and unit cell compositions of the prevailing PbPc monolayer and multilayer domains are confusingly similar to those of SnPc on PTCDA/Ag(1 1 1). However, SnPc and PbPc can be readily distinguished by their STM-induced switching behaviours: while the former is capable of reversible configurational changes, no effect on the latter could be achieved by us under comparable conditions. This corroborates earlier theoretical predictions and even renders the chemical identification of individual shuttlecock-shaped metal-phthalocyanines feasible.