IR and IR/UV spectroscopy on Metal-Ligand Clusters

Anionic, cationic and neutral clusters of transition metals and aromatic or aliphatic ligands are studied in order to determine their structure and reactivity in molecular beam experiments.

By means of IR-photodetachment, IR multi photon dissociation and photo electron spectroscopy we analyze vibrational frequencies to characterise the structure of the anionic clusters. Neutral clusters can be analyzed by application of e.g. IR/PIRI method (cf. figure 3).

Analyses of metal clusters and aromatic ligands provide an insight into the transition from smaller molecular systems to models for nano-structured phases. A successive aggregation of ligands (e.g. benzene and ethanol) to metal clusters of different sizes can be investigated. The elementary processes on a molecular level provide a contribution for basic research on reactions catalyzed by metals. Mono-, bi-, tri-, and tetranuclear systems are analyzed in cooperation with other research groups within the SFB/TRR 88 to investigate cooperative effects with respect to spin states and catalysis.

Figure 1: Competing structural motifs for cationic clusters consisting of three cobalt atoms (yellow), ethanol, and water.

Figure 2: Different structures of  Co / Benzene clusters.