Ab initio Calculations and Qualitative Valence Bond Considerations for H₂N-NO₂ (Nitramide) and H₂N-NO (Nitrosamine)

Abstract

The structures, energies and vibrational frequencies of H2N-NO2 and H2N-NO have been calculated at HF, MP2(FC), MP2(FULL) and CISD levels of theory using a polarized triple-zeta 6-311+G(d,p) basis augmented with a diffuse function. In addition, the structures and energies were also computed at the QCISD(T)/6-311+G(d,p) level of theory. The structure and bonding in H2N-NO2 and H2N-NO is discussed on the basis of a Natural Bond Orbital Analysis (NBO analysis) and in addition based on qualitative valence bond (VB) considerations.

Experimental and Theoretical Study on the Structure of Nitramide H2NNO2

“…Nitro-compounds are of special interest because of their high energy content [1,2]. The properties of such molecules were studied both theoretically and experimentally.…”

“…It has been characterized by vibrational spectroscopy in the solid state [10], in solution [10], in Ar-matrix [11] and in the gas phase [12] as well as by UV spectroscopy [13]. 1 H and 14 N NMR spectra were also recorded [14]. The gas phase structure was investigated by vibrational 0932-0776/02/0200-0151 $ 06.00 c 2002 Verlag der Zeitschrift für Naturforschung, Tübingen Á www.znaturforsch.com K spectroscopy [12] and electron diffraction [15].…”

“…Xray structure determination was also reported with large standard deviations where the position of the hydrogen atoms could not be located precisely [16]. The bonding situation was studied with ab initio calculations and qualitative valence bond considerations by our group [1]. More precise data including the positions of the hydrogen atoms was obtained by our group from a low temperature X-ray structure determination [17].…”