Silylaminyl radicals. Part 3. Electron spin resonance studies of alkyl(trialkylsilyl)aminyl radicals
作者:John C. Brand、Malcolm D. Cook、Brian P. Roberts
DOI:10.1039/p29840001187
日期:——
spin-orbit coupling for the unpaired electron on nitrogen in RṄSiR3, as a result of a reduction in the energy required to promote a σ lone-pair electron into the π SOMO. These conclusions are supported by the results of MNDO molecular orbital calculations. The lifetimes of the alkyl (silyl) aminyls increase with the extent of steric shielding of the nitrogen radical centre. The aminyl cyclo-C4H7ṄSiButMe2
Hydrogen-atom abstraction from dimethylamine in solution: EPR spectroscopic studies and ab initio molecular orbital calculations
作者:Patrick E. Elford、Brian P. Roberts
DOI:10.1039/a800590g
日期:——
minyl radicals with dimethylamine in cyclopropane solution have been studied using EPR spectroscopy. Both radicals abstract hydrogen competitively from the NH and CH groups to produce the radicals Me2N˙ and MeNHĊH2, respectively, but the silylaminyl radical shows a greater propensity to attack the less sterically hindered methyl groups. Analogous trends are shown in hydrogen-atom abstraction from propane
Synthesis of (1,2,4‐Oxadiazole)palladium(
<scp>II</scp>
) Complexes by [2 + 3] Cycloaddition of Nitrile Oxides to Organonitriles in the Presence of PdCl
<sub>2</sub>
作者:Nadezhda A. Bokach、Vadim Yu. Kukushkin、Matti Haukka、Armando J. L. Pombeiro
DOI:10.1002/ejic.200400580
日期:2005.3
the nitrileoxides 2,4,6-R' 3 C 6 H 2 CNO (R' = Me, OMe) and trans-[PdCl2 (RCN) 2 ], or RCN (R = Me, Et, CH 2 CN, NMe 2 , Ph) in the presence of PdCl2 , proceeded smoothly under mild conditions and allowed the isolation of the 1,2,4-oxadiazole complexes trans-[PdCl2 (N a =C(R)-ON=C b (C 6 H 2 R' 3 )(N a -C b )} 2 ] (1-8) in 40-85% yields. In CH 2 Cl 2 , the reaction between 2,4,6-R' 3 C 6 H 2 CNO
通过与1,2-双(二苯基膦基)乙烷或过量的Na 2 S.7H 2 O在MeOH中的取代反应,成功地从1-8中释放杂环物质;释放的 1,2,4-恶二唑 (11-18) 通过正离子 FAB 质谱和 1 H 和 1 3 C 1 H} NMR 光谱表征。
Effects of ionizing radiation on cyanamide and dimethylcyanamide
作者:Aidan B. O'Connell、Harish Chandra、Shuddhodan P. Mishra、Akinori Hasegawa、Martyn C. R. Symons
DOI:10.1039/ft9918703129
日期:——
Irradiation of the pure title compounds and a range of dilute solid solutions produces a range of matrix-isolated radicals, identified by their EPR spectra. These include electron-loss centres, HNCN and (Me2NCN)+, and electron capture centres HNC(H)N˙– and Me2N˙. The former is a tautomer of the parent anion and the latter is formed by loss of CN–. In aqueous alkali glasses, the radical anion ˙N2CO3– is thought to be formed by addition of O˙– to CN2–2.
Formation of the dimethylamino radical from the radical cation of tetramethylurea: an electron spin resonance–radiation chemical study
作者:Martyn C. R. Symons
DOI:10.1039/c39860000011
日期:——
Exposure of dilute solutions of tetramethylurea in dichlorofluoromethane to 60Co γ-rays at 77 K gave e.s.r. features characteristic of dimethylamino radicals with no indication of any features for the parent radicalcations.