XAFS and XEOL of tetramesityldigermene - An electronic structure study of a heavy group 14 ethylene analogue

Journal Article · Wed May 29 00:00:00 EDT 2013 · Journal of Physics. Conference Series

DOI:https://doi.org/10.1088/1742-6596/430/1/012046· OSTI ID:1081350

Ward, Matthew J.; Rupar, Paul A.; Murphy, Michael W.; Yiu, Yun-Mui; Baines, Kim M.; Sham, Tsun-Kong ^[1]

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1. UWO

Digermene, the germanium analogue of ethylene, has a multiple bonding motif that differs greatly from that of alkenes and exhibits no pure σ or π type bonds. The electronic structure of digermenes is difficult to study experimentally due to their reactivity, and is computationally challenging because of their shallow potential energy surfaces. Using X-ray absorption near edge structures at both the germanium K and L edges we have been able to directly probe the unoccupied electronic states, or the lowest unoccupied molecular orbital (LUMO), and LUMO+ etc. in the Ge=Ge bond of tetramesityldigermene. We have demonstrated that the LUMO, LUMO+, etc. are composed of hybrid Ge 4s and 4p orbitals. Additionally, our data suggest that the LUMO exhibits relatively more Ge 4s character, whereas the LUMO+ and LUMO+2 exhibit relatively more Ge 4p character. An X-ray excited optical luminescence study of Ge₂Mes₄ revealed one broad optical emission band at 620 nm, which is significantly red shifted compared to the known energy gap of this molecular germanium compound.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: DOE - BASIC ENERGY SCIENCES
• OSTI ID: 1081350
• Journal Information: Journal of Physics. Conference Series, Vol. 430, Issue (1) ; 2013; Conference: Beijing, China; ISSN 1742-6588
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: ENGLISH