Interaction in olefin–NO+ complexes: structure and dynamics of the NO+–2,3-dimethyl-2-butene complex

Nitrosonium complexes of organic compounds. Structure and reactivity

“…44 The structure of the nitrosonium complex with 2,3-dimethylbut-2-ene was analysed in detail by 1 H and 13 C NMR spectroscopy using the isotope perturbation method and by ab initio quantum-chemical (6-31G* basis set) and IGLO calculations. 50 As in the case of the ethylene ± NO + isomers, the calculations predicted the existence of two types of complexes characterised by the symmetry C 2u (26) and the approximate symmetry C s (27). In these complexes, the distances from the N atom to the C=C bond are 0.1225 and 0.2183 nm, respectively.…”

“…The equivalence of the C(2) and C(3) atoms and the equivalence of the carbon atoms of the methyl groups observed in the 13 C NMR spectrum of the complex 27 were attributed either to the inversion of the nitrogen atom or to the rotation of the NO group about the axis passing through the nitrogen atom perpendicular to the C(2)7C(3) bond as well as to the high rate of migration of this group. 50 Complexes of different alkenes with the [NO] + [BF 4 ] 7 and [NO] + [PF 6 ] 7 salts and with other sources of the nitrosonium cation (RONO ± CF 3 CO 2 H, NOCl ± CF 3 CO 2 H and N 2 O 4 ± SbF 5 ) were investigated. 51 At low temperature, the electronic spectra of 2,3-dimethylbut-2-ene, 2,3,4-trimethylpent-2-ene and adamantylideneadamantane have charge-transfer bands.…”