Carbenes and nitrenes. An overview

A brief survey of the structure, methods of generation and reactivity of the singlet and triplet carbenes and nitrenes is given. The DFT and CCSD(T) calculations of the singlet–triplet energy gap ΔEST for a large number of differently substituted carbenes and nitrenes are performed and the dependence of ΔEST on the substituent(s) at the sextet center is discussed.