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The solid‐state structure of decamethylsilicocene Cp*2Si with a bent and a linear molecule in the same unit cell was so far considered an exception in relation to the structures of its all‐bent heavier analogues Cp*2E with E=Ge, Sn, Pb. Here, we present the solution to this conundrum by reporting a low‐temperature phase, where all three symmetrically independent molecules are present in a bent formation. This reversible enantiotropic phase transition occurs in the temperature range between 80 K and 130 K and provides a rationale for the unexpected linear molecule based in entropy beyond hand‐waving explanations such as electronic reasons or packing effects. [ABSTRACT FROM AUTHOR]

Bislang galt die Struktur des Decamethylsilicocens Cp*2Si mit einem gewinkelten und einem linearen Molekül in derselben Elementarzelle als die Ausnahme unter den ansonsten ausschließlich gewinkelten schweren Homologen Cp*2E mit E=Ge, Sn, Pb. Hier stellen wir des Rätsels Lösung mit einer Tieftemperaturphase vor, in der alle drei symmetrieunabhängigen Moleküle die gewinkelte Konformation einnehmen. Der reversible Phasendurchgang geschieht im Temperaturbereich zwischen 80 und 130 K und bietet eine rationale Erklärung auf der Grundlage der Entropie. Nebelhafte Erklärungsversuche mit Packungseffekten werden damit überflüssig. [ABSTRACT FROM AUTHOR]

The solid-state structure of decamethylsilicocene Cp* 2 Si with a bent and a linear molecule in the same unit cell was so far considered an exception in relation to the structures of its all-bent heavier analogues Cp* 2 E with E=Ge, Sn, Pb. Here, we present the solution to this conundrum by reporting a low-temperature phase, where all three symmetrically independent molecules are present in a bent formation. This reversible enantiotropic phase transition occurs in the temperature range between 80 K and 130 K and provides a rationale for the unexpected linear molecule based in entropy beyond hand-waving explanations such as electronic reasons or packing effects., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The synthesis and initial observations regarding the reactivity of borole-based half-sandwich complexes with apical divalent group 14 elements germanium and tin are described. The 2,5-disilylborole substitution pattern allows their access via salt metathesis of the respective borole dianions.