Chemistry of Mixed Sulfur-, Selenium-, or Tellurium- and Silicon-, or Tin-Containing Heterocycles

Abstract

Lone pair ionization energies for 1,5-dichalcogenocanes containing endocyclic 3,7-R₂Si groups and the parent 1,5-dichalcogenocanes, estimated from the TCNE charge-transfer wavelength maxima, are in good agreement with ionization energies directly obtained from photoelectron spectroscopy. These data indicate the occurrence of substantial intra-annular interaction between the chalcogen atoms and silyl groups, consistent with the well-known β -effect of silicon and the novel β-disilyl effect, when R (in R ₂ Si) is Me ₃ Si.

Keywords:

• 1,5-dithiocane
• 5-thiaselenocane
• β-disilyl effect
• β-stannyl effect
• β-silyl effect
• chalcogen heterocycles
• photoelectron spectroscopy
• TCNE charge transfer bands

Acknowledgments

The authors gratefully acknowledge support of this work by the donors of the Petroleum Research Fund administered by the American Chemical Society (EB, RSG), the National Science Foundation (CHE-9906566, CHE-0342660, CHE-0450505, CHE-0744578, EB; CHE-0201555, CHE-0455575, RSG), and NCS through a super-computing grant (EL). This work was done, in part, at the Center for Gas-Phase Electron Spectroscopy, The University of Arizona.

Notes

^a Solvent is CH₂Cl₂

^b reacts with TCNE.