African Journal of
Pure and Applied Chemistry

  • Abbreviation: Afr. J. Pure Appl. Chem.
  • Language: English
  • ISSN: 1996-0840
  • DOI: 10.5897/AJPAC
  • Start Year: 2007
  • Published Articles: 354

Full Length Research Paper

Theoretical study of phthalane oxidation and effect of substituents by using Hyperchem program

Mohammed Oday Ezzat and Mohd Nizam Mordi*  
Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.  
Email: [email protected]

  •  Accepted: 12 March 2012
  •  Published: 30 April 2012


The effect of substituents on the relative stabilization energy (ERS) of phthalane-X carbocations has been studied with PM3 semi-empirical molecular orbital theory. The results show that the amino group gives ERS less than zero for very big amount and that will increase stability of carbocation by π-electron donation, whereas the nitro group gives height amount of ERS more than zero and that will lead to difficulties of an intermediate carbocation formation because of its strong σ- and π-accepting nature. ERS decreases with increase in the phenyl rings attached to cation. When electron withdraws substituents attached, it will destabilize the cation, because they act as π-electron donors.


Key words: Relative stabilization energy (ERS), PM3 semi-empirical, isodesmic reactions.