Synthesis, decomposition, and structural studies in the gas phase and solid state of N,N-dimethylaminoxygermane

N,N-Dimethylaminoxygermane, H3GeONMe2, was prepared by the reaction of H3Ge Br with LiONMe2 in dimethyl ether at -96 degreesC. The identity of H3GeONMe 2 was proven by gas-phase IR and solution NMR spectroscopy (H-1, C-13, N-15 , O-17). It is unstable volatile liquid compound. It decomposes by cleavage of a Ge-O and a Ge-H bond giving HONMe2 and an insoluble germanium hydride polymer (GeH2)(n). This decomposition reaction has been modeled at the MP2 /6-311G(d,p) level of theory by the homodesmotic reaction H3GeONMe2 + Ge2H6 --> Ge3H8 + HONMe2, which is predicted slightly exothermic by 14 kJ mol(-1 ). The molecular structure of H3GeONMe2 was determined by gas-phase electro n diffraction supported by an ab initio geometry [MP2/6-311G(d,p)] and a fo rce field [MP2/6-31G(d)]. The structure of the compound in the crystal latt ice was determined by low-temperature crystallography using a single crysta l of H3GeONMe2 grown in situ [C2H9NOGe, orthorhombic, Pnma, Z = 4, a = 8.12 80(12) Angstrom, b = 9.7037(15) Angstrom, c = 7.0722(12) Angstrom]. Importa nt bond lengths and angles (gas phase/solid state, Angstrom /deg) are Ge-O 1.785(2)/1.815(1), O-N 1.462(7)/1.460(2), N-C 1.460(4)/1.453(2), Ge-O-N 105 .2(5)/104.6(1), O-N-C 105.8(5)/105.8(1), C-N-C 110.8(9)/111.2(2), Ge...N 2. 587(6)/2.601(1). In the solid state the compound forms infinite chains by i ntermolecular Ge...O contacts of 2.808 Angstrom. The question of the attrac tion between Ge and N atoms is discussed with respect to reference Ge/O and N/O compounds, which have wider angles at oxygen than H3GeONMe2. For compa rison the structures of the compounds H3CONMe2, H3SiONMe2, and H3SnONMe2 we re also calculated to reflect the influence of the group 14 atom on the str ucture and to discuss the occurrence of weak E...N interactions in the comp ounds H3EONMe2.