Related Experiment Videos
A Steeply Pyramidal Silylamine: N,O-Dimethyl-N-silylhydroxylamine
Norbert W. Mitzel1, Heinz Oberhammer
1Anorganisch-chemisches Institut, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany, and Institut für Physikalische und Theoretische Chemie, Universität Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
Inorganic Chemistry
|October 24, 2001
Summary
N,O-Dimethyl-N-silylhydroxylamine was synthesized and characterized. This silyl nitrogen compound exhibits a pyramidal nitrogen atom, challenging previous assumptions about silylamine structures and bonding.
Area of Science:
- Organosilicon Chemistry
- Inorganic Chemistry
- Computational Chemistry
Background:
- Silyl nitrogen compounds are crucial in various chemical applications.
- Understanding the electronic and structural properties of these compounds is essential for designing new materials and catalysts.
- Previous studies suggested planar nitrogen coordination in silylamines due to electronic effects.
Purpose of the Study:
- To synthesize and characterize N,O-Dimethyl-N-silylhydroxylamine (H(3)SiMeNOMe).
- To elucidate the structural and electronic properties of H(3)SiMeNOMe.
- To investigate the decomposition pathway and stability of the synthesized compound.
Main Methods:
- Synthesis via reaction of HMeNOMe with H(3)SiBr and 2,6-lutidine.
- Characterization using gas-phase IR, solution NMR (1H, 13C, 15N, 17O, 29Si), and mass spectrometry.
- Structural determination through gas-phase electron diffraction and ab initio calculations.
- Computational analysis including NBO (Natural Bond Orbital) analysis.
Main Results:
- Successful synthesis and characterization of H(3)SiMeNOMe.
- H(3)SiMeNOMe exhibits a steeply pyramidal nitrogen atom and a trans conformation, the first silyl nitrogen compound with pyramidal nitrogen for electronic reasons.
- The Si-N bond is only slightly elongated compared to compounds with planar nitrogen.
- Decomposition observed at ambient temperature, likely via methylnitrene extrusion, yielding SiH(4) and a precipitate.
Conclusions:
- H(3)SiMeNOMe represents a novel class of silyl nitrogen compounds with a pyramidal nitrogen center.
- The observed pyramidal geometry challenges established theories on nitrogen coordination in silylamines.
- The compound's instability suggests specific decomposition pathways that warrant further investigation.