Chemical Physics Letters vol:349 issue:5-6 pages:571-577
date:Acad Sinica, Inst Atom & Mol Sci, Taipei 10764, Taiwan; Univ Louvain, Dept Chem, B-3001 Louvain, Belgium; Hochiminh City Univ Technol, Fac Chem Engn, Grp Computat Chem, Thanh Pho Ho Chi Minh, Vietnam
Singlet-triplet separation and heat of formation of phenylcarbene were calculated by using the B3LYP, RCCSD(T), G2M, G3, CASSCF, CASPT2 and MRCI methods. Our calculated values are 2.5 +/- 1 kcal/mol for the singlet-triplet splitting energy, 113.5 +/- 1 kcal/mol for the standard heat of formation (DeltaH(f 298)(0)) of singlet phenylcarbene, and 111.0 +/- 2 kcal/mol for the standard heat of formation of triplet phenylcarbene. While the singlet-triplet separation is in good agreement with previous theoretical and experimental data, the standard heat of formation of triplet phenylcarbene is about 7-8 kcal/mol higher than the experimental value (103.8 +/- 2.2 kcal/mol by Squires et al. [J. Chem. Soc., Perkin Trans. 2 (1999) 2249]). (C) 2001 Elsevier Science B.V. All rights reserved.