Azaisoquinolinones: N positions tell you different stories in their optical properties

J Org Chem. 2013 Dec 20;78(24):12760-8. doi: 10.1021/jo402338n. Epub 2013 Dec 10.

Abstract

Since isoquinolinones and their derivatives have been demonstrated to be powerful building blocks in constructing larger acenes and twistacenes, azaisoquinolinones and their analogues could also be important intermediates to approach larger N-heteroacenes. In this paper, we are interested in developing a concise method to synthesize novel azaisoquinolinones building blocks and studying their physical properties. Our results showed that the different N positions have a large effect on the optical and electrochemical properties of azaisoquinolinones. For example, protonation of 6- and 7-azaisoquinolinones shows different shifts of UV-vis and FL spectra. More interestingly, 6- and 7-azaisoquinolinones exhibited different interactions with metal ions in CH3CN solution. Upon the addition of 2 equiv of Fe(3+), 6-azaisoquinolinone displayed an absorption wavelength red-shifted from 470 to 540 nm (Δλ = 70 nm) with a color change from yellow to red, while the interaction between Fe(3+) and 7-azaisoquinolinone was very weak and there was no obvious color change (Δλ = 18 nm). Moreover, theoretical calculations confirmed the different optical properties with 6- and 7-azaisoquinolinones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aza Compounds / chemical synthesis
  • Aza Compounds / chemistry*
  • Hydrogen-Ion Concentration
  • Isoquinolines / chemical synthesis
  • Isoquinolines / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Optical Phenomena
  • Quantum Theory

Substances

  • Aza Compounds
  • Isoquinolines