PUB - Publikationen an der Universität Bielefeld

The reaction of dialkylzinc compounds R2Zn (R = Me, Et) with N,N-dimethylhydrazine and trimethylsilanol in a 4: 2: 2 ratio leads to the formation of tetra(alkylzinc) tris-siloxide mono-hydrazide aggregates, [(RZn)(4)(NHNMe2)(OSiMe3)(3)] [R = Me (1) and Et (2)]. These compounds are aggregates of mirror symmetry, containing the novel Zn4N2O3 core. Both compounds have been characterised by H-1, C-13 and Si-29 NMR and IR spectroscopy, by mass spectrometry and by elemental analysis, and 2 also by X-ray crystallography. The structure can be derived from a heterocubane, in which one anionic vertex is replaced by an NHNMe2 group contributing two N atoms to the core constitution. By applying a ratio of hydrazine: silanol of 2: 1 in a reaction with R2Zn (R = Me, Et, iPr), compounds of the general formula [(RZn)(4)(NHNMe2)(2)(OSiMe3)(2)] [R = Me (3), Et (4), iPr (5)] are obtained. These aggregates contain a Zn4N4O2 core. Upon employing a hydrazine: silanol ratio of 5: 1 in a reaction with diisopropyl zinc, the compound [(iPrZn)(4)(NHNMe2)(3)(OSiMe3)] results, containing a Zn4N6O unit. Compounds 3-6 have been characterised by H-1, C-13 and Si-29 NMR and IR spectroscopy, by mass spectrometry and by elemental analysis. The topologic relationship between the pure hydrazides [(RZn)(4)(NHNMe2)(4)], the mixed aggregates [(RZn)(4)(NHNMe2)(3)(OR')], [(RZn)(4)(NHNMe2)(2)(OR')(2)] and [(RZn)(4)(NHNMe2)(3)(OR')(3)] and the pure alkoxides [(R-Zn)(4)(OR')(4)] is discussed.