A Cyclopentadienide Analogue Containing Divalent Germanium and a Heavy Cyclobutadiene-like Dianion with an Unusual Ge4 Core.

The article examines the synthesis of new types of cyclopentadienides (Cp) analogues containing divalent group 14 elements, which may lead to electron-rich transition metal complexes with unusually high reduction potential, owing to the presence of strong electropositive low-valent group 14 metals. According to the authors, to their knowledge, no Cp analogues containing low-valent heavier group 14 elements are known as yet.