New polynuclear indium nitrogen compounds -: Synthesis and crystal structures of [In4X4(NtBu)4] (X = Cl, Br, I) and [In3Br4(NtBu)(NHtBu)3]

The reaction of the indium trihalides InX3 (X = Cl, Br, I) with (LiNHBu)-Bu-t in THF leads to the In4N4-heterocubanes [In4X4((NBu)-Bu-t)(4)] (X = Cl 1, Br 2, I 3). Additionally [In3Br4((NBu)-Bu-t)((NHBu)-Bu-t)(3)] (4) was obtained as a by-product in the synthesis of 2. 1-4 have been characterized by x-ray crystal structure analysis. 1-3 consist of In4N4 heterocubane cores with an alternating arrangement of In and N atoms. The In atoms are coordinated nearly tetrahedrally by three N-atoms and a terminal halogen atom. 4 contains a tricyclic In3N4 core which can be formally derived from an In4N4-heterocubane by removing one In atom.