Theoretical calculation of the steric effects of ortho substituents by the AM1 method

Tomoko Sotomatsu, Yoshiyuki Murata, Toshio Fujita

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The AM1 calculation was done for ortho‐substituted toluenes (o‐X‐C6H4‐CH3) and ortho‐substituted tert‐butylbenzenes (o‐X‐C6H4‐t‐Bu). The difference in the calculated heat of formation between o‐X‐C6H4‐CH3 and o‐X‐C6H4‐t‐Bu was used as a theoretical steric index for ortho‐X. The correlation of this theoretical steric index with the empirical steric parameter sets such as our recently defined Es(AMD) and the Taft–Kutter–Hansch (TKH) Es was examined. In spite of the simplicity of the model system, the theoretical index was linear with the Es(AMD) constant with a correlation coefficient of r = 0.972 for 17 substituents of various structures. Including the phenyl group, the correlation with the TKH Es constant was r = 0.948. The theoretically calculated index was shown to serve as a measure of the ortho steric effect.

Original languageEnglish
Pages (from-to)135-138
Number of pages4
JournalJournal of Computational Chemistry
Issue number1
Publication statusPublished - 1991
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics


Dive into the research topics of 'Theoretical calculation of the steric effects of ortho substituents by the AM1 method'. Together they form a unique fingerprint.

Cite this