Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (01): 55-63.doi: 10.3866/PKU.WHXB201210151

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Characterization and Density Functional Theory Investigations of 3-Monoacylaminoquinazolinone Derivatives

AL-SEHEMI Abdullah G.1,2, Al-AMRI Reem S. Abdulaziz1, IRFAN Ahmad1   

  1. 1 Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia;
    2 Unit of Science and Technology, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia
  • Received:2012-07-04 Revised:2012-10-13 Published:2012-12-14
  • Supported by:

    AL-AMRI ReemS. Abdulaziz was supported by the King Abdul Aziz City of Science and Technology (KACST) (GSP-18-138).

Abstract:

Several 3-aminoquinazolin-4-(3H)-one derivatives were synthesized and characterized. Using proton nuclear magnetic resonance (NMR) spectra, we have investigated the barriers to rotation around the N-N bond as a function of temperature. Changes in the NMR spectra at high temperatures are explained in terms of hindered rotations of the N-N bond. Free energies of activation for the rate determining stereochemical process were calculated to be as high as 67-75 kJ·mol-1. Ground state molecular geometries and vibrational frequencies were calculated using the HF/6-31G** and B3LYP/6-31G** level of theories. The optimized bond lengths and bond angles are in good agreement with experimental values at both theoretical levels.

Key words: 3-Monoacylaminoquinazolinones, Density functional theory, Geometry, NMR, IR