1 A.N.Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilov str., 28, 119991 Moscow, Russia. bilyachenko@ineos.ac.ru.
The first Ni(ii)-based metallagermaniumsesquioxane cage compound [(PhGeO1.5)10(NiO)4(NaO0.5)2] presents a sandwich-like structure where two germsesquioxane cages are linked through an {NiO}4 core and exhibits slow dynamics of the magnetization.