NO-induced reversible switching of the electronic interaction between a porphyrin-coordinated cobalt ion and a silver surface
NO-induced reversible switching of the electronic interaction between a porphyrin-coordinated cobalt ion and a silver surface
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DOI：
10.1021/ja0756725
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发表时间：
2007-10-10
影响因子：
15
通讯作者：
Gottfried, J. Michael
中科院分区：
文献类型：
--
作者：
Flechtner, Ken;Kretschmann, Andreas;Gottfried, J. Michael
通过配位在钴离子上的轴向一氧化氮(NO)配体，改变了配位的钴离子与银表面之间的电子相互作用。这一过程是可逆的，并用X射线和紫外光电子能谱(XPS和UPS)进行了监测。Co-Ag相互作用导致电子从Ag表面转移到Co离子，并在费米能级附近形成新的电子态。如果一个轴向的NO配位到Co离子上，这两种效应都消失了，这表明Co-Ag相互作用被抑制。作为一种可能的解释，我们讨论了Co离子上两个轴向配体之间的竞争，类似于反式效应：NO分子和Ag表面。这些发现对传感器技术和负载型金属卟啉的催化具有重要意义，在负载型金属卟啉上，金属中心的催化活性受与下表面的相互作用控制。
The electronic interaction between a porphyrin-coordinated Co ion and a silver surface was switched by an axial nitric oxide (NO) ligand on the Co ion. This process is reversible and was monitored with X-ray and UV-photoelectron spectroscopy (XPS and UPS). The Co-Ag interaction leads to an electron transfer from the Ag surface to the Co ion and to a new electronic state close to the Fermi level. Both effects vanish if an axial NO ligand coordinates to the Co ion, indicating that the Co-Ag interaction is suppressed. As a possible explanation, we discuss a competition, similar to the trans effect, between the two axial ligands on the Co ion: the NO molecule and the Ag surface. These findings have important implications for sensor technology and for catalysis on supported metalloporphyrins, in which the catalytic activity of the metal center is controlled by the interaction with the underlying surface.