Sesquibicyclic hydrazines: oxidation thermodynamics and cation radical nitrogen ESR splittings and UV absorption maxima

Ionized Bicyclo[2.2.2]oct-2-ene: A Twisted Olefinic Radical Cation Showing Vibronic Coupling

“…It should be realized, however, that the splittings calculated for the minimum‐energy structure are not those that would be observed experimentally. The a (H x ) and a (H v ) splittings are quite sensitive to both ϕ and ψ twisting, and the energy surface is flat enough that Boltzmann averaging over both ϕ and ψ twisting would have to be considered for accurate estimation of splitting constants 22. Because both ϕ and ψ must change sign to interconvert C 2 structures, the energy surface is presumably of the “Mexican hat” type that avoids the ϕ = ψ =0° C 2v maximum‐energy point 7b,7c.…”

syn-Sesquinorbornenyl carbocations and their boron analogues: an ab initio and DFT study

“…A number of X-ray studies of crystalline synsesquinorbornene derivatives also appeared in the meantime, 6 which have shown that the double bond in 1 indeed deviates from planarity, exhibiting hinge-like endo bending characterised by the out of plane angle . [7][8][9][10][11] Closely related to this feature is an observation that such molecules exhibit pronounced π-facial selectivity in their addition reactions. 6a In recent years we have been concerned with the syntheses, 12 the spatial structure analyses 13 and the electronic structure investigations 14 of a variety of heteroatom analogues of 1.…”

Ab initio MO and DFT study of syn-sesquinorbornatrienyl dication and its isoelectronic boron analogueElectronic supplementary information (ESI) available: bond distances and bond angles of structures 6a, 6c, 7a and 7c calculated at the MP2/6-31+G* and B3LYP/6-31G* levels of theory (Table S1). See http://www.rsc.org/suppdata/nj/b4/b403802a/

“…23 The positive values of the out-of-plane angle are used to describe structures in which the substituents at the double bonds are oriented toward the endo site of molecule, and the negative values to the structures in which the substituents at the double bond are oriented toward the exo site of the molecule. [23][24][25][26][27] The tilting angles describe the angles between the plane containing electron-deficient bridge, (C(3)-X(11)-C(4)/C(5)-X(12)-C( 6)), and the C b C=CC b plane, where C b stands for the bridged carbon atoms.…”