The Nitroparaffins.

Nitroxide decomposition: Implications toward nitroxide design for applications in living free‐radical polymerization

“…This three-electron p system effectively forms a bond order of one-and-a-half as indicated by the bond energy of 100 kcal/mol, midway between the energy of a NÀ ÀO single bond (53 kcal/mol) and a N¼ ¼O double bond (145 kcal/mol). 88 The gain in energy from the delocalization of the unpaired electron has been calculated to be approximately 30 kcal/mol. 89 Nitroxides are commonly formed by the treatment of corresponding hydroxylamines such as 1 with mild oxidants such as oxygen, with or without a catalyst (Scheme 1).…”

Nitroxide Radicals: Properties, Synthesis and Applications

“…As a result of this three-electron N-O π system, the N-O bond of an aminoxyl group has a bond order of 1.5, as indicated by the bond energy of about 100 kcal/mol, and the bond length d NO (1.25Å < d NO < 1.30Å), which is midway between the energy and the bond length of a N-OH single bond (53 kcal/mol; ∼ 1.43Å) and a N=O double bond (145 kcal/mol; ∼ 1.20Å) 11d, 13 .…”

“…301 In vivo metabolic production of lactate and alanine after the injection of hyperpolarized 13 C 1 pyruvate in a rat. 13 At high magnetic field in the solid state (90 K) and pumping at 260 GHz microwave frequency, Griffin reported that using biradicals as polarizing agents, the Cross Effect (CE) mechanism leads to improved polarization enhancements when comparing with Solid Effect (SE) and Thermal Mixing (TM) mechanisms. The more efficient biradicals (Scheme 5.64) consist of two TEMPO nitroxides tethered by an ethylene glycol chain (106), 302 a more water soluble TEMPO-based dinitroxide bearing a propan-2-ol tethering chain (Totapol, 107), 303 and a rigid binitroxide bearing orthogonal TEMPO moieties (bTbK, 108).…”

“…Left)13 C NMR spectra at 9.4 T and room temperature of (A) urea (59.6 mM in water) hyperpolarized by the DNP-NMR method and (B) urea (59.6 mM in water) at thermal equilibrium (acquisition time: 65 h) (Reprinted from[285], Copyright 2003, with permission from National Academy of Sciences, U.S.A.)285 (Right) …”

Formation of Lower Nitro Alkanes by Vapor Phase Nitration of Cyclic Hydrocarbons

“…the intermediate formation of alpha nitro acids (I), the oxidation or nitration of nitro derivatives initially formed, the addition of nitric acid to the hydrocarbon with the formation of a complex which is decomposed into nitro derivatives and alcohols (2), the following mechanisms are now considered as probable: (A) Breaking of the C-C bond of the hydrocarbon with simultaneous formation of two nitro derivatives (2) mation of nitric oxide and alkoxy radicals, the latter being decomposed to a lower alkyl radical and formaldehyde (3)…”