Experimental and theoretical study of the circular dichroism spectra of oxa- and thia- [2.2] metacyclophane

https://doi.org/10.1016/0009-2614(93)85414-JGet rights and content

Abstract

The excited electronic states of (−)-(M)-1-oxa [2.2] metacyclophane and (−)-(M)-1-thia[2.2] metacyclophane are discussed in the light of experimental UV/VUV optical absorption and circular dichroism (CD) spectra and multireference configuration interaction (MRD-CI) calculations of excitation energies and rotatory strengths. As one-particle basis, semi-empirical AM1 and MNDOC wavefunctions expressed in terms of localized molecular orbitals (LMO) are used. Good agreement between experimental and calculated CD spectra is obtained by correlating only a small portion of the 80 valence electrons of the compounds. The dominant CD transitions of the oxa [2.2] metacyclophane can be characterized as separate and coupled ππ* transitions localized in the aromatic rings. The CD spectrum of the thia [2.2] metacyclophane is mainly described by valence-type excitations involving the lone-pair orbital of the sulphur atom (3p) and/or anti-bonding σ* MOs of CS bonds; localized ππ* transitions are of lower intensity.

References (33)

  • T.-K. Ha et al.

    Chem. Phys. Letters

    (1991)
  • M. Carnell et al.

    Chem. Phys. Letters

    (1991)
  • T.-K. Ha et al.

    Chem. Phys. Letters

    (1991)
  • B.O. Roos et al.

    Chem. Phys. Letters

    (1992)
  • Y. Okamoto et al.

    J. Am. Chem. Soc.

    (1981)
  • F. Vögtle et al.

    Angew. Chem.

    (1972)
  • F. Vögtle et al.

    J. Chem. Soc. Chem. Commun.

    (1986)
  • M.B. Robin
    (1974)
  • S. Bohan et al.

    J. Am. Chem. Soc.

    (1986)
  • V. Buss et al.

    Chem. Ber.

    (1988)
  • M. Iseli et al.
  • M.J.S. Dewar et al.

    J. Am. Chem. Soc.

    (1985)
  • W. Thiel

    J. Am. Chem. Soc.

    (1981)
  • J.A. Pople et al.

    J. Chem. Phys.

    (1965)
  • R.J. Buenker et al.

    Theoret. Chim. Acta

    (1974)
    R.J. Buenker et al.

    Theoret. Chim. Acta

    (1975)
  • S. Grimme, submitted for...
  • Cited by (44)

    • Optical activities of steroid ketones - Elucidation of the octant rule

      2018, Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
      Citation Excerpt :

      In 1970's, however, Gould and Hoffmann successfully calculated optical activities of asymmetric small ketones by using the extended Hückel method [2], which was the first landmark of the computational studies on optical activities by one-electron theory. As for the semi-empirical methods, the prediction of optical activities by one-electron theory was later achieved by CNDO [3], AM1 [4], CNDO/S, INDO/S (ZINDO) [5], and was succeeded by modern versions RM1, PM3, PM6, and PM7 [6]. Nowadays, calculations of eigenfunctions from ab initio or DFT methods are not so difficult, thanks to rapid advances in computation resources.

    View all citing articles on Scopus
    View full text