Quantum-chemical studies of the structure and reactivity of carbenes

The results of quantum-chemical studies on the electronic and geometrical structures and of the singlet–triplet splitting of carbenes (methylene and its derivatives, including unsaturated and cyclic carbenes) are examined and surveyed. The factors regulating the geometrical characteristics and the multiplicity of the electronic ground state of carbenes are discussed. The features of the reaction pathways leading to the addition of electrophilic and nucleophilic carbenes to single and double bonds and the structures of the transition states are analysed. 191 references.