Boccalini, Alberto, Dyson, Paul J., Femoni, Cristina, Iapalucci, Maria C., Ruggieri, Silvia, and Zacchini, Stefano
The reaction of the [Rh7(CO)16]3− cluster anion with Ge2+ salts, in different stoichiometric ratios and under different atmospheres, leads to the formation of new heterometallic Rh–Ge clusters, representing the first known examples of Rh carbonyl compounds containing interstitial germanium atoms. More specifically, under N2 the reaction progressively affords the new [Rh13Ge(CO)25]3− and [Rh14Ge2(CO)30]2− clusters in good yields, with the Ge atoms located in cubic and square-anti-prismatic cavities, respectively. However, under a CO atmosphere, the [Rh13Ge(CO)25]3− derivative undergoes a significant structural and chemical rearrangement giving the new compound, [Rh12Ge(CO)27]4−, where Ge is hosted in an icosahedral metal cage. All species have been characterized by IR spectroscopy and ESI mass spectrometry, and their structures have been elucidated by single-crystal X-ray diffraction. Additionally, preliminary biological tests on the [Rh13Ge(CO)25]3− and [Rh14Ge2(CO)30]2− clusters show that they are cytotoxic to various cell lines. [ABSTRACT FROM AUTHOR]