Organozinc Siloxide-Hydrazide Aggregates [(RZn)4(NHNMe2)x(OSiMe3)(4 – x)]
Zeitschrift für Naturforschung. B, A journal of chemical sciences
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 monohydrazide 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 1H, 13C and 29Si NMR and IR spectroscopy, by mass spectrometry and by elemental analysis, and 2 also by X-ray
... 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 1H, 13C and 29Si 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 [(RZn)4(OR')4] is discussed.