Optical and Vibrational Properties of [Pt@Pb-12](2-), [Ni@Pb-12](2-), and [Ni@Pb-10](2-) Zintl Ion Clusters

The optical and vibrational properties of Pt- and Ni-centered Pb-Zintl-ion clusters have been investigated by UV/Vis and FTIR spectroscopy. Computational studies have been performed to better interpret the experimental data, due to a lack of any FTIR and UV/Vis spectroscopic studies on these clusters or similar ones in the literature. UV/Vis spectroscopic analyses show an asymmetric broad absorption band, with a maximum at 265 nm for both Pt- and Ni-centered Pb clusters. FTIR spectroscopic analysis demonstrated that the vibrational modes of the clusters appear at the low-frequency (terahertz) range of the spectrum. Vibrational modes of [Pt@Pb-12](2-) and [Ni@Pb-12](2-) are observed at 74 cm(-1), and those of [Ni@Pb-10](2-) appear at 86, 143, and 200 cm(-1). Similarities between simulated and experimental spectra strongly support isolated cluster behavior. [Pt@Pb-12](2-), [Ni@Pb-12](2-), and [Ni@Pb-10](2-) are the only Zintl ion clusters that have been characterized with UV/Vis and FTIR spectroscopic analyses to elucidate their optical and vibrational properties.