Low-Valent MxAl3 Cluster Salts with Tetrahedral [SiAl3]+ and Trigonal-Bipyramidal [M2Al3]2+ Cores (M=Si/Ge) |
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| Authors: | Philipp Dabringhaus Silja Zedlitz Luisa Giarrana David Scheschkewitz Ingo Krossing |
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| Institution: | 1. Albert-Ludwigs-Universität Freiburg, Institute for Inorganic and Analytical Chemistry, Freiburg Materials Research Center FMF, Albertstraße 21, 79104 Freiburg i. Br., Germany;2. Chair in General and Inorganic Chemistry, Saarland University, 66123 Saarbrücken, Germany |
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| Abstract: | Schnöckel's (AlCp*)4] and Jutzi's SiCp*]B(C6F5)4] (Cp*=C5Me5) are landmarks in modern main-group chemistry with diverse applications in synthesis and catalysis. Despite the isoelectronic relationship between the AlCp* and the SiCp*]+ fragments, their mutual reactivity is hitherto unknown. Here, we report on their reaction giving the complex salts Cp*Si(AlCp*)3]WCA] (WCA]?=Al(ORF)4]? and F{Al(ORF)3}2]?; RF=C(CF3)3). The tetrahedral SiAl3]+ core not only represents a rare example of a low-valent silicon-doped aluminium-cluster, but also—due to its facile accessibility and high stability—provides a convenient preparative entry towards low-valent Si?Al clusters in general. For example, an elusive binuclear Si2(AlCp*)5]2+ with extremely short Al?Si bonds and a high negative partial charge at the Si atoms was structurally characterised and its bonding situation analysed by DFT. Crystals of the isostructural Ge2(AlCp*)5]2+ dication were also obtained and represent the first mixed Al?Ge cluster. |
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| Keywords: | Aluminium Bond Theory Cluster Compounds Silicon Weakly-Coording Anions |
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