Evidence for the 1-thia-3-sila-2,4-diazetidine heterocyclic system with three parallel lone pairs from an e.s.r. spectroscopic study of its cation radical

Formation of the new electron-rich heterocyclic system (But)[graphic omitted]i, an intermediate during the reductive cyclosilylation of ButNSNBut with Me2SiCl2/2Li, was established by an e.s.r. spectroscopic analysis of its persistent cation radical after oxidation with AlCl3/CH2Cl2.