The golden era of germanium: The largest known germanium cluster [Au3Ge45]9− consists of 45 Ge atoms coordinated to three Au atoms and is obtained by the reaction of K4Ge9 and [AuCl(PPh3)]. DFT calculations reveal the large variety of chemical‐bond character in the {Ge45} moiety; localized two‐center, two‐electron bonds coexist with delocalized polyhedral and three‐center, two‐electron bonds.

The chemistry of anionic Group 14 Zintl ions have had a reawakening [1] with respect to the discovery of novel and larger structures and chemical reactivity. Whereas Group 10 transition metals tend to form intermetalloid clusters with Zintl ions, such as in [M@Pb 12 ] 2À (M = Ni, Pd, Pt), [2] [M@Sn 9 ML] [3] (1). The stability of such a cluster offers valuable clues to both the use as a catalytic seed for the growth of (germanium) nanowires [7] and the use of the cluster itself as a building block for one-dimensional systems.Cluster compound 1 was obtained through the reaction of [Au(PPh 3 )Cl] with an ethylenediamine solution of the phase K 4 Ge 9 in the presence of [2.2.2]crypt (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane). After filtration, the solution was carefully layered with toluene, and dark-orange to red plate-shaped crystals were obtained after one week. Semiquantitative energy-dispersive X-ray (EDX) analyses of the crystals showed the approximate ratio of Au/Ge/K = 3:18:5. Single-crystal X-ray structure determination and refinement [8] of 1 in the triclinic space group P1 showed that 1 contains the anionic cluster [Ge 9 Au 3 Ge 9 ] 5À ( Figure 1)

Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problembased learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues.

Closed encounters: A closed deltahedral homoatomic cluster, [Pb10]2−, is structurally characterized. When this “empty” cluster is considered together with the recently published filled cluster [Ni@Pb10]2−, a striking parallel to the fullerenes emerges: Zintl ions form polyhedral cages that can enclose a central atom without any major structural alterations.

Goldene Zeiten für Germanium: Der bislang größte Germaniumcluster besteht aus 45 Germaniumatomen und drei Goldatomen. Man erhält das Anion [Au3Ge45]9− aus der Reaktion von K4Ge9 mit [AuCl(PPh3)]. DFT‐Rechnungen belegen, dass in der {Ge45}‐Einheit eine große Bandbreite an chemischen Bindungsarten realisiert wird: Lokalisierte Zweizentren‐Zweielektronen‐Bindungen treten neben delokalisierten und Dreizentren‐Zweielektronen‐Bindungen auf.