Journal of the American Chemical Society, Vol.118, No.11, 2664-2668, 1996
The Pyramidal Si2N-O Skeleton of O-Methyl-N,N-Disilylhydroxylamine - An Inherent Phenomenon as Confirmed by Structural Studies in Different Phases
O-Methyl-N,N-disilylhydroxylamine, (H3Si)(2)NOCH3 (1), has been prepared by the reaction of bromosilane with O-methylhydroxylamine in the presence of 2,6-lutidine. The compound has been found to be reasonably stable at ambient temperature, but explodes if heated to 200 degrees C. 1 has been completely characterized by MS, HRMS, IR in the solid state and gas phase, and NMR spectra of the nuclei H-1, C-13, N-14/15, O-17, and Si-29. The NMR chemical shifts are compared with those of Si-methylated derivatives and with values obtained in high-level ab initio calculations. It has been concluded that there is close similarity between the structure in solution and the calculated one. A single crystal of 1 grown in situ and studied by X-ray diffraction is orthorhombic, space group P2(1)2(1)2(1), a = 6.3664(11) Angstrom, b = 8.488(2) Angstrom, c = 11.783(4) Angstrom, rho(calc) = 1.119 g cm(-1), Z = 4. Intermolecular Si ... O interactions (2.92 Angstrom) are found in the solid state structure leading to a zigzag type aggregation of the molecules. The gas phase structure of 1 has been determined by electron diffraction showing the molecule to have C-S symmetry. In both phases, the crystalline and the gas phase, the nitrogen atom configuration of 1 is pyramidal [