Geometric structure of the N-methylnitramine and N-chloro-N-methylnitramine molecules in the gaseous phase

Experimental and Theoretical Study on the Structure of Nitramide H2NNO2

“…The calculations on the MPW1PW91 level of theory give the best agreement with the experimental data. The N-N bond length from electron diffraction in the gas phase is 1.381Å [15]. The calculated bond length of the external molecules is 1.373Å, and the N-N bond length of the central unit is shortened to 1.324Å, in good agreeement with the value [1.319(2)Å] determined here by X-ray diffraction.…”

“…The product was purified by sublimation under reduced pressure. The colorless crystals have a melting range of 81 -84 C. 15 Crystals suitable for an X-ray crystallographic study were grown by vacuum sublimation at room temperature. The data sets were collected on a NONIUS KAPPA CCD diffractometer with graphite-monochromated Mo-K radiation at various temperatures (a: 100 K, b: 140 K, c: 170 K, d: 230 K, e: 260 K).…”

“…side-on: a 0.86(2) a 2.24 (2) a 3.064(1) X-ray dif-X-ray difElectron diffraction (b) fraction [16] fraction [15] bond lengths [1.318(2)Å (f) to 1.322(2)Å (a)] are significantly shorter than in the gas phase (1.381Å) [15] and also shorter than the reported crystal phase N-N bond length of 1.40Å [16]. The authors of the previously reported crystal structure analysis assumed that nitramide is planar [16].…”

“…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].…”

Molecular structure of N-chlorosuccinimide studied by gas-phase electron diffraction and quantum-chemical methods

“…It can be noted, that in the solid state, due to influence of crystal field the NCS molecule has lower symmetry as well as significantly different bond lengths in comparison with parameters of free molecule (see Table 5). The determined thermal-average r g (N-Cl) bond length of 1.685(3) Å in NCS is considerably shorter than those in chloramines with pyramidalized nitrogen (for example, r a (N-Cl) = 1.720(4) Å in N-chloro-N-nitromethanamine [27], r g (N-Cl) = 1.759(2) Å in N,N-dichloroethanamine [28], r g (N-Cl) = 1.762(2) Å in N,N-dichloro-2-propanamine [28]). There are only a few exceptions for the compounds with the N-Cl bond shorter than 1.70 Å [15,16] (for example, in tetrafluorosulfur chloroimide dimer r a (N-Cl) = 1.638(10) Å [29]).…”