Qualitative valence-bond descriptions of bonding for S-N, S-O, S-F and S-S compounds via increased-valence structures

摘要: Abstract Valence-bond (VB) structures are developed for a variety of molecular species with S-S, S-O, S-Y (Y = H, CH 3 , or halogen) and S-N bonds, one more sets three-electron two-centre, four-electron three-centre six-electron four-centre bonding units. The valence bond that mostly considered the increased-valence type, one-electron fractional electron-pair bonds normal bonds. If sulphur atoms do not utilize their d atomic orbitals as in structures, then many these may be obtained by together ground states diatomic monatomic components. participation primary VB is assumed to occur when atom carries formal charge + 2 Kekule-type octet Lewis i.e. either occurs structures. On basis bond-length considerations, it suggested expansion shell R SO type compounds, alkyl aryl. In no expansion, S-O S-S double represented S÷O S÷S, respectively, instead SO SS. equivalent resonance between Kekule- Dewar-type structures; therefore they must always provide representations which lower energy than those (as usually done) only considered. Inclusion an “increased-valence” component structure reduces extent required order on small magnitude.