METHYL SUBSTITUTION IN CARBENES - A THEORETICAL PREDICTION OF THE SINGLET-TRIPLET ENERGY SEPARATION OF DIMETHYLCARBENE

Ab initio calculations on the singlet-triplet energy separation of dim etylcarbene are reported. Correlation methods based on a single determ inant reference function as well as the multiconfigurational approach are used in combination with various basis sets. Our best calculation predicts, inaccord with recent experiments, a singlet-triplet splittin g of 1.64 kcal/mol in favor of the singlet state of dimethylcarbene.