Synthese und Kristallstruktur der molekularen Clusterverbindung W6Br14 |
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Authors: | Jrg Saßmannshausen Hans-Georg von Schnering |
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Institution: | Jörg Saßmannshausen,Hans-Georg von Schnering |
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Abstract: | Synthesis and Crystal Structure of the Molecular Cluster Compound W6Br14 Brownish-black crystals of W6Br14 are formed in the direct synthesis from W6Br12 and Br2 (400 K). The compound crystallizes cubically with neutral cluster molecules (W6Br]Br): a = 13.458 Å; Pn3 (Nr. 201); d?(W? W) = 2.653 Å; d?(W? Bri) = 2.616 Å; d?(W? Bra) = 2.569 Å. The W atoms are 0.03 Å outside of the Br cube faces. The molecules are arranged according to a cF point configuration, but each is rotated ?23° about a threefold axis in order to avoid short inter cluster distances Bra? Bra. Nevertheless, via 12 short intermolecular distances per cluster of about d(Bri …? Bra) = 3.487 Å the clusters are interconnected by forming two independent and interpenetrating 3D nets (Cu2O type). Although local distortion of the M6X cluster does not occur, as is expected for this system with 22 electrons per M6 octahedron, it is assumed that the Jahn-Teller theorem is fulfilled collectively via the low-symmetry nets of intermolecular interactions. |
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Keywords: | Tungsten bromide cluster compound W6Br14 synthesis crystal structure |
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