GeCp big 2 [Cp big = C 5 (CH 2 C 6 H 4 ‐ i Pr) 5 ]: A Flexible Sandwich Molecule

GeCp big 2 ( 1 ) [Cp big = C 5 (CH 2 C 6 H 4 ‐ i Pr) 5 ] was synthesized by a reaction of KCp big either with a GeCl solution or GeCl 2 and was obtained as colorless crystals. The molecular structure of 1 was determined by X‐ray diffraction, showing that 1 features two pentahapto bonded Cp big ligands in a bent configuration with a Cp big ‐Ge–Cp big angle of 161°. Two out of ten benzyl substituents point towards the lone pair at the germanium atom so that two molecules fit perfectly together, leading to a dimeric arrangement of 1 within the solid state. Two polymorphs of 1 could be isolated, where 1 is oriented in a different way. As indicated by quantum chemical calculations, the open structure, where all benzyl substituents point away from the germanium atom is only disfavored by 21.6 kJ · mol –1 . In the open structure a bent arrangement is still realized, giving access to the lone pair at the germanium atom for further applications, e.g. in coordination chemistry.