Photoelectron and electron transmission spectra of thiete 1,1-dioxide, thietane 1,1-dioxide and related compounds. The sulfone effect on a highly react

X-ray Diffraction, UV Photoelectron, and Ab Initio Study of Intramolecular Interactions in .beta.-Carbonyl Sulfones

“…or negative (-0.22(S) e), depending upon the electronegativity of the heterogroup X.28 At the same time, the negative charge at the carbonyl oxygen atom increases in the oxygen (10) and, above all, in the nitrogen (6 and 7) derivatives. These charge variations, coupled with the change of 0(1)-C(2) bond distance already mentioned, unveil the presence of a delicate balance of electronic effects between the X and C=0 fragments (see below).…”

“…From refs 8-10. * This peak contains contributions from other ionization processes.d This spectrum was not resolved beyond ca 10…”

Molecular and Electronic Structure of 1,8-Peribridged Naphthalenes

“…We recall that the bands associated with the ionizations from oxygen lone pairs are expected to show an increase in relative intensity on going from HeI to HeII radiation. Taking into consideration relative band intensities, HeI/HeII intensity changes, and comparison with the spectra of naphthalene, thiete 1,1′dioxide 19 (7e), and diphenyl sulfone (Ph-SO 2 -Ph), 18 we conclude that bands at 8.25 and 10.05 eV correspond to ionizations from π 5 and π 3 type orbitals, respectively. The band at 9.5 eV contains two ionizations (it has twice the intensity of 8.25 eV band): one from the π 4 type orbital and one from the oxygen lone pair (n O ).…”

“…The molecule 7 does not have sulfur lone pairs, but its sulfone group introduces four additional valence ionizations (strongly localized on oxygens) that can be detected in the low-energy UPS region. 19 The oxygen lone pairs of appropriate symmetry are capable of resonant interactions with the π-orbitals of the aromatic system, provided they are well matched in energy. 19 In addition, the electronegative oxygens are expected to exercise inductive stabilization on all π-ionizations.…”

“…19 The oxygen lone pairs of appropriate symmetry are capable of resonant interactions with the π-orbitals of the aromatic system, provided they are well matched in energy. 19 In addition, the electronegative oxygens are expected to exercise inductive stabilization on all π-ionizations. We recall that the bands associated with the ionizations from oxygen lone pairs are expected to show an increase in relative intensity on going from HeI to HeII radiation.…”