Self-Assembly and Properties of Nonmetalated Tetraphenyl-Porphyrin on Metal Substrates
详细信息 查看全文
- 作者：Geoffrey Rojas ; Xumin Chen ; Cameron Bravo ; Ji-Hyun Kim ; Jae-Sung Kim ; Jie Xiao ; Peter A. Dowben ; Yi Gao ; Xiao Cheng Zeng ; Wonyoung Choe ; Axel Enders
- 刊名：Journal of Physical Chemistry C
- 出版年：2010
- 出版时间：May 27, 2010
- 年：2010
- 卷：114
- 期：20
- 页码：9408-9415
- 全文大小：282K
- 年卷期：v.114,no.20(May 27, 2010)
- ISSN：1932-7455
文摘
The structure−electronic structure relationship of nonmetalated meso-tetraphenyl porphyrin (2H-TPP) on the (111) surfaces of Ag, Cu, and Au was studied with a combination of scanning tunneling microscopy, photoelectron spectroscopy, and density functional theory. We observe that the molecules form a 2D network on Ag(111), driven by attractive intermolecular interactions, while the surface migration barriers are comparatively small and the charge transfer to the adsorbed molecules is minimal. This is in contrast to a significant charge transfer observed in 2H-TPP/Cu(111), resulting in repulsive forces between the molecules that prevent molecular adlayer network formation. It is shown that the limiting factor in formation of self-organized networks is the nature of the frontier orbital overlap and the adsorbate−interface electron transfer. Further, the electronic structure, most notably the HOMO−LUMO splitting, are found to be dependent on the substrate as well. The comparison of the results in this article with published work on similar porphyrins suggests that the molecule−substrate interaction strength is determined by the molecule’s metalation, and not so much by the ligands.