Chemical and Physical Properties of Anthronylidene

Article abstract of DOI:10.1021/jo00252a023

Irradiation of diazoanthrone (DAAN) leads to loss of nitrogen and to formation of the carbene anthronylidene (AN).The triplet ground state of this carbene was detected at low temperature by ESR and optical spectrometric methods and at room temperature in fluid solution by laser flash photolysis.The rate constants for the reaction of ³AN with olefins, saturated hydrocarbons, and alcohols were determined spectrometrically.Combination of these kinetic measumerents with the results of chemical competition studies permits estimation of the energy gap separating the ground triplet state from the lowest singlet state of AN(ΔG_ST) to be 5.8 +/- 0.6 kcal/mol.This value is compared with that of other related carbenes and with the estimate obtained from MINDO/3 calculations for AN.