The influence of the FeCp(CO)2+ moiety on the dynamics of the metalloid [Ge9(Si(SiMe3)3)3]- cluster in thf: Synthesis and characterization by time-resolved absorption spectroscopy

Abstract

A neutral tetrasubstituted Ge9 cluster with a covalently bound transition metal substituent was synthesized successfully via a salt metathesis reaction. Photoexcitation of [Ge9(Si(SiMe3)3)3FeCp(CO)2] induces excited state dynamics of the compound that was analysed by extended broadband fs absorption spectroscopy in the UV-Vis-NIR region. After UV or Vis excitation, an electron is detached from the [Ge9(Si(SiMe3)3)3]--entity and localizes within few hundred fs. Recombination of this cluster-electron-pair occurs in about 7-9 ps. Finally, a third component can be attributed to complete ground state recovery within roughly 150 ps. This is much shorter compared to a longer-lived component within Li[Ge9(Si(SiMe3)3)3], whose transient absorption exceeds the ns timescale after UV excitation. This observation emphasizes a strong influence of the Fe moiety.