In this project in the Organic Dynamics Program, Professor Joseph B. Lambert from the Chemistry Department at Northwestern University will study "New Organic Intermediates Containing Silicon or Tin". He will explore the interactions between the element and adjacent positive charge in order to study the phenomenon of hyperconjugation. Efforts will be made to use silylenium ions to provide new methods for carbon-silicon and silicon-silicon bond formation and to serve as catalysts for polymerization reactions that may lead to new materials. Positively charged species containing silicon, tin, or other Main Group elements will be used to study hyperconjugation. Tin and lead will be used to study delocalization of positive charge over many sigma bonds in order to prove a new mechanism called multiple stage hyperconjugation. The spatial dependence of hyperconjugation in vinyl and saturated systems will be studied. New strategies will be devised for obtaining silylenium, germylenium, and phosphenium ions with greater ionicity and stability. Silylenium ions will be used to provide new methods for carbon-silicon and silicon-silicon bond formation and to serve as catalysts for polymerization reactions that may lead to new materials. The exceptional ability of tin to stabilize positive charge will be used to create new phenyl and vinyl cations.
