- High quantum yield molecular bromine photoelimination from mononuclear platinum(IV) complexes
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Pt(IV) complexes trans-Pt(PEt3)2(R)(Br)3 (R = Br, aryl and polycyclic aromatic fragments) photoeliminate molecular bromine with quantum yields as high as 82%. Photoelimination occurs both in the solid state and in solution. Calorimetry measurements and DFT calculations (PMe3 analogs) indicate endothermic and endergonic photoeliminations with free energies from 2 to 22 kcal/mol of Br2. Solution trapping experiments with high concentrations of 2,3-dimethyl-2-butene suggest a radical-like excited state precursor to bromine elimination.
- Raphael Karikachery, Alice,Lee, Han Baek,Masjedi, Mehdi,Ross, Andreas,Moody, Morgan A.,Cai, Xiaochen,Chui, Megan,Hoff, Carl D.,Sharp, Paul R.
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p. 4113 - 4119
(2013/05/09)
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- Comparison of gif-type reactivity towards alkanes with standard radical reaction selectivity. Gif oxidation of n-butane and propane
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A precise comparison has been made between radical bromination of a series of saturated hydrocarbons using BrCCl3 and the bromination of the same series with the same reagent under Gif-type (GoAggIII) conditions. The relative reactivities in the two series are completely different and confirm a difference in mechanism. Experiments with n-butane and with propane have shown that these gases react with the usual Gif selectivity to furnish 2-butanone and acetone respectively.
- Barton, Derek H. R.,Csuhai, Eva,Doller, Dario,Ozbalik, Nubar,Senglet, Nathalie
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p. 3097 - 3100
(2007/10/02)
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- Reactions of a Graded Set of Radicals with N-Bromosuccinimide; Two Transition States
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The reactions of N-bromosuccinimide with a series of radicals have been studied.These reactions fall into two categories, the more reactive radicals producing ?-succinimidyl and the less reactive radicals producing ?-succinimidyl.The threshold for the changeover from one reaction domain to the other occurs with radicals less reactive than secondary alkyls.These results are interpreted with two transition states, an in-line transition state for the more reactive radicals and an out-of-plane transition state for the less reactive radicals. An upper limit of 18 kcal/mol is established for the enthalpy difference, HS? - HS?.Two new methods for generating S? radicals are indicated.
- Tlumak, Robert L.,Skell Philip S.
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p. 7267 - 7274
(2007/10/02)
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- Halogenation with N-Halo-2-oxazolidinones. The Chain-carrying N-Centered Radicals
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Selectivities in halogenation of 2,3-dimethylbutane, 1-chlorobutane and substituted toluenes with N-chloro- or N-bromo derivatives of 4,4-dimethyl-2-oxazolidinone (NXDMO), 2-oxazolidinone (NXO), and succinimide (NXS) were examined.In the presence of olefi
- Migita, Toshihiko,Nakayama, Mitsumasa,Watanuki, Toshiro,Suzuki, Mikio,Kosugi, Masanori
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p. 822 - 827
(2007/10/02)
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