Theoretical study of structural patterns in CH2OP2 isomers

DFT calculations have been performed on the derivatives of formula CH 2 OP 2 to determine their total energy, the relative energy between the isomers and their geometry. Among compounds with a P-C-P linkage, the most stable one is the 2-hydroxy-1,2-diphosphirene II.1 , a three-membered heterocycle with a P=C unsaturation. The phosphavinylidene(oxo)phosphorane HP=C=P(O)H IV.5 (which has the same skeleton as the experimentally obtained Mes*P=C=P(O)Mes*) lies 36.30 kcal mol -1 above it. The least stable compounds are carbenes; the singlet carbenes are more stable than the triplet ones.