నైరూప్య

Understanding the stability of two different geometrical isomers instable phosphorus ylides derived from benzotriazole: A quantum mechanical study.

Hojjat Ghasempour, Mohammad Zakarianejad, Sayyed Mostafa Habibi-Khorassani, Batoul Makiabadi, Simin Norozpour

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reactions between triphenylphosphine and dialkylacetylenedicarboxylates, in the presence of NH-heterocyclic compound, such as benzotriazole. These stable ylides usually exist in solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon-carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group.In the recent work, stability of the Z- and the E- isomers were undertaken for the two rotamers of phosphorus ylides involving benzotriazoleby natural population analysis (NPA) and atoms in molecules (AIM) methods.