30967-37-4Relevant articles and documents
C-H bond dissociation enthalpies in norbornane. An experimental and computational study
Nunes, Paulo M.,Estcio, Slvia G.,Lopes, Gustavo T.,Costa Cabral, Benedito J.,Dos Santos, Rui M. Borges,Simes, Jos A. Martinho
, p. 1613 - 1616 (2008)
Gas-phase C-H bond dissociation enthalpies (BDEs) in norbornane were determined by quantum chemistry calculations and the C2-H BDE was experimentally obtained for the first time by time-resolved photoacoustic calorimetry. CBS-Q and CBS-QB3 methods were us
STRUCTURES AND REACTIONS OF RADICAL CATIONS OF SOME BICYCLOALKANES AND THEIR RELATED ALKENES AS STUDIED BY 4 K MATRIX ESR
Nunome, Keichi,Toriyama, Kazumi,Iwasaki, Machio
, p. 6315 - 6324 (2007/10/02)
The ? radical cations of most typical bicycloalkanes such as norbornane and bicyclooctane are radiolytically produced at 4 K in halogenocarbon matrices and are studied by ESR spectroscopy.Their electronic and geometrical structures as well as their dynamical behaviors have been elucidated from the hyperfine structures and their temperature changes.The semi occupied molecular orbital (SOMO) of the former cation is 4a2, in which the unpaired electron delocalizes over the four exo C-H bonds giving large hyperfine coupling.The latter is a Jahn-Teller active species and exhibits static distortion from D3h to C2v at 4 K in CFCl3, and the SOMO is likely to be 6b2, in which the unpaired electron delocalizes over the four endo C-H bonds giving large proton coupling, although a dynamically averaged structure with 12 equivalent methylene protons is observed in c-C6F12 as well as in CFCl2CF2Cl matrices at 77 K.The unpaired electron distribution in bicycloalkane radical cations is similar to that in cycloalkane radical cations previously studied.Upon warming both the cations undergo deprotonation to give 2-yl alkyl radicals from the exo or endo C-H bond, at which the higher unpaired electron density is populated.In addition to these radical cations, the structures and reactions of the radical cations of the related bicycloalkenes such as norbornadiene, quadricyclane, and bicyclooctene have also been studied.The hydride ion transfer to an olefinic radical cation to form an alkyl radical is observed for the bicyclooctene radical cation as the first example observed by ESR.
