Johansson E M J, Hedlund M, Odelius M, Siegbahn H, Rensmo H
Department of Physics, Uppsala University, P.O. Box 530, SE-75121 Uppsala, Sweden.
J Chem Phys. 2007 Jun 28;126(24):244303. doi: 10.1063/1.2738066.
The frontier electronic structures of Ru(tcterpy)(NCS)3 [black dye (BD)] and Ru(dcbpy)2(NCS)(2) (N719) have been investigated by photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES). N1s XAS has been used to probe the nitrogen contribution in the unoccupied density of states, and PES, together with RPES over the N1s edge, has been used to delineate the character of the occupied density of states. The experimental findings of the frontier electron structure are compared to calculations of the partial density of states for the nitrogens in the different ligands (NCS and terpyridine/bipyridine) and for Ru4d. The result indicates large similarities between the two complexes. Specifically, the valence level spectra show two well separated structures at low binding energy. The experimental results indicate that the outermost structure in the valence region largely has a Ru4d character but with a substantial character also from the NCS ligand. Interestingly, the second lowest structure also has a significant Ru4d character mixed into the structure otherwise dominated by NCS. Comparing the two complexes the BD valence structures lowest in binding energy contains a large contribution from the NCS ligands but almost no contribution from the terpyridine ligands, while for N719 also some contribution from the bipyridine ligands is mixed into the energy levels.
通过光电子能谱（PES）、X射线吸收光谱（XAS）和共振光电子能谱（RPES）研究了Ru(tcterpy)(NCS)3[黑色染料（BD）]和Ru(dcbpy)2(NCS)(2)（N719）的前沿电子结构。N1s XAS用于探测未占据态密度中的氮贡献，而PES以及N1s边缘上的RPES则用于描绘占据态密度的特征。将前沿电子结构的实验结果与不同配体（NCS和三联吡啶/联吡啶）中氮以及Ru4d的态密度计算结果进行了比较。结果表明这两种配合物之间有很大的相似性。具体而言，价带光谱在低结合能处显示出两个明显分开的结构。实验结果表明，价带区域中最外层的结构在很大程度上具有Ru4d特征，但也有来自NCS配体的显著特征。有趣的是，第二低的结构在以NCS为主导的结构中也混入了显著的Ru4d特征。比较这两种配合物，结合能最低的BD价带结构中NCS配体的贡献很大，但三联吡啶配体几乎没有贡献，而对于N719，联吡啶配体也有一些贡献混入了能级中。
