1,721,066 research outputs found
Ab initio study of the nuclear spin-spin coupling constants and magnetic shielding constants in silicon derivatives via the Equation of Motion method
No full textTheoretical ab initio calculation of the indirect nuclear spin-spin coupling constants of monohetero cyclopropanes and cyclopropenes via the Equation of Motion method
No full textAb initio study of the J(BB) and J(BH) coupling constants in polyboranes via the coupled-Hartree-Fock and Equation of Motion methods
No full textTheoretical determination of the indirect nuclear spin-spin coupling tensors, nuclear screening tensors, and magnetic susceptibilities of multiply bonded systems via the Equation of Motion method
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Electron Attachment to Di-tert-butylperoxide, Artemisinin, and b-Artemether.
No full textThe gas-phase dissociative electron attachment spectra of di-tert-butylperoxide (DBP) and the antimalarial polycyclic peroxides artemisinin and b-artemether are presented for the first time. The total anion currents measured at the walls of the collision chamber and the mass selected anion currents are reported in the 0-6 eV energy range.
Electron attachment to DBP produces an intense current, peaking at 1.3 eV, due to the C4H9O- negative fragment, in line with the strongly O-O antibonding character of the singly occupied orbital of the parent molecular anion and the small (if any) thermodynamic energy threshold predicted by B3LYP calculations for the formation of this anion fragment. A five times less intense signal, with m/e = 57 and a maximum at 0.7 eV, is also observed. The calculations exclude that this signal can be associated with the C4H9- negative fragment, whereas support its assignment to the C3H5O- species, generated by simultaneous dissociation and loss of a methane molecule from the parent molecular anion.
In DBP, artemisinin, and b-artemether, currents corresponding to the parent molecular anion are not detected, indicating that its survival time is shorter than the time required (about 10-6 s) to pass through the mass filter. In the latter two compounds, where simple O-O bond breaking does not generate separate fragments, the anion currents are much weaker than in DBP and the maximum total anion current peaks at zero energy
Ab initio application of the Equation of Motion method to the excited states of allene, ketene and diazomethane
No full textAb initio study of the low-lying excited states of cyclopropene by the Equation of Motion method
No full textGreen's Function ab initio study of the outer valence ionization energies of monoheterocyclopropenes
No full textAb initio investigation of the electron correlation effect on Ramsey's terms of the nuclear spin-spin coupling tensor
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