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Free keywords:
chemical bonding, germanium, high-pressure synthesis, intermetallic compound, lutetium
Abstract:
Abstract The monogermanide LuGe is obtained via high-pressure high-temperature synthesis (5?15?GPa, 1023?1423?K). The crystal structure is solved from single-crystal X-ray diffraction data (structure type FeB, space group Pnma, a=7.660(2)?Å, b=3.875(1)?Å, and c=5.715(2)?Å, RF=0.036 for 206 symmetry independent reflections). The analysis of chemical bonding applying quantum-chemical techniques in position space was performed. It revealed?beside the expected 2c-Ge-Ge bonds in the germanium polyanion?rather unexpected four-atomic bonds between lutetium atoms indicating the formation of a polycation by the excess electrons in the system Lu3+(2b)Ge2??1?e?. Despite the reduced VEC of 3.5, lutetium monogermanide is following the extended 8-N rule with the trend to form lutetium-lutetium bonds utilizing the electrons left after satisfying the bonding needs in the anionic Ge-Ge zigzag chain.
