74732-64-2Relevant academic research and scientific papers
The chain carriers of intermolecular hydrogen abstraction in the photobromination with N-bromosuccinimide; modifications of the chain carriers
Zhang, Yu-Huang,Dong, Ming-Hua,Jiang, Xi-Kui,Chow, Yuan L.
, p. 1668 - 1675 (2007/10/02)
The photoinitiated bromination of 1-chloropentane with N-bromosuccinimide (NBS) in the presence of Br2 is compared with that of NBS and 1,1-dichloroethene to generate the succinimidyl radical (S radical) and with that of Br2 + K2CO3 to generate the bromine atom (Br radical) as the chain carriers.The relative reactivities of intermolecular H-abstraction (r-values) shown by the NBS + Br2 system decrease to levels lower than those shown by either S radical or Br radical chain propagations at lower temperatures under appropriate conditions: these observations indicate thepresence of a new chain propagating species that is assumed to be the bromine radical complex (BRC) modified from S radical or Br radical reversibly under the experimental conditions.Supporting evidence for the equilibria of S radical, Br radical, and BRC in the photodecomposition of NBS + Br2 is discussed.The unusual H-abstraction reactivity of Br radical toward the methyl hydrogens of 1-chloropentane was noted; this serves as independent support for the presence of a new radical propagation species.
