The benzidine rearrangement is claimed to be an example of the quite rare [5,5] sigmatropic migration[cite]10.1021/ja00335a035[/cite], which is a ten-electron homologation of the very common [3,3] sigmatropic reaction (
e.g.
the Cope or Claisen). Some benzidine rearrangements are indeed thought to go through the [3,3] route[cite]10.1021/ja00309a041[/cite]. The topic has been reviewed here[cite]10.1002/poc.610020702[/cite]. In
Published in European Journal of Inorganic Chemistry
Authors Carles Miró Sabaté, Henri Delalu
AbstractN,N′‐Dimethylhydrazine and several of its salts with energetic anions were synthesized and fully characterized by elemental analysis, DSC, mass spectrometry, multinuclear NMR (1H, 13C, and 15N) spectroscopy, and vibrational (Raman, IR) spectroscopy. According to the DSC measurements, the compounds exhibit good thermal stabilities, and the nitrate (2) and dicyanamide (4) salts belong to the ionic‐liquid type (i.e., Tm < 100 °C). Additionally, the solid‐state crystal structure of the nitrate [2: triclinic, P$\bar {1}$, a = 5.360(2) Å, b = 5.806(2) Å, c = 6.866(2) Å, α = 113.73(2)°, β = 92.44(2)°, γ = 90.08(2)°, V = 195.4(1) Å3], perchlorate [3: orthorhombic, Pbca, a = 11.774(2) Å, b = 11.072(3) Å, c = 14.050(3) Å, V = 1831.6(7) Å3], sulfate [5: monoclinic, P21/n, a = 5.913(1) Å, b = 9.509(1) Å, c = 10.351(1) Å, β = 90.29(1)°, V = 582.0(1) Å3], monopicrate [6b: monoclinic, P21/c, a = 10.910(1) Å, b = 6.7436(1) Å, c = 16.442(2) Å, β = 103.40(1)°, V = 1176.7(2) Å3], and dipicrate dihydrate [6·2H2O: monoclinic, P21/n, a = 8.230(1) Å, b = 13.024(1) Å, c = 10.642(1) Å, β = 104.43(1)°, V = 1104.7(2) Å3] salts were determined. Furthermore, a natural bond orbital (NBO) analysis of the structure of the [MeNH2–NH2Me]2+ cation was performed. Standard tests were used to examine the sensitivity of the compounds towards impact, friction, and electrostatic discharge. Lastly, the heats of formation of the compounds were calculated by means of quantum chemical calculations and used to determine the detonation parameters and specific impulses of the compounds and those of mixtures with an oxidizer.
Organic ChemistryPhysical and Theoretical Chemistry
Published in Journal of Physical Organic Chemistry
Author Henry J. Shine
AbstractThe ups and downs, and reasons therein, of the π‐complex theory of the mechanism of the benzidine rearrangements, and the possible role of π‐complexes in a newer understanding of the rearrangements, are described.
Colloid and Surface ChemistryBiochemistryGeneral ChemistryCatalysis