Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 65: Density functional theory and beyond for real materials III
O 65.7: Vortrag
Donnerstag, 25. März 2010, 12:00–12:15, H34
A DFT study on electronic structure and vibronic properties of d8 (Ni-, Pd-, and Pt-) phthalocyanines — •Davoud Pouladsaz1, Thiruvancheril G. Gopakumar2, and Michael Schreiber1 — 1Institut für Physik, Technische Universität Chemnitz — 2Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel
We studied the HOMO-LUMO gap shrinking in order to investigate the tip-induced polarization in scanning tunneling spectroscopy of d8 (Ni, Pd, and Pt) phthalocyanines [1]. By means of density functional theory (DFT), the molecular orbital energies have been calculated for Ni-, Pd-, and PtPc single neutral molecules and singly and doubly ionized cations and anions of all molecules. Interestingly, the position of the HOMO decreases systematically with increasing the atomic number of the central metal atom. The first ionization energies of neutral molecules increase by changing the central metal atom, while the electron affinities remain constant. This causes an increase in the HOMO-LUMO gap. These results show a clear correlation to experimental observations. Furthermore, we performed a DFT study on photoelectron spectra of the first and the second ionizations of these molecules, computing the vibronic couplings and the reorganization energies. The partitioning of the reorganization energy into normal mode contributions shows that the major contributions are due to several vibrational modes with a1g symmetry lower than 1600 cm−1.
[1] Th. G. Gopakumar, J. Meiss, D. Pouladsaz, and M. Hietschold, J. Phys. Chem. C, 112, 2529 (2008)