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 Fe3+, 6-azaisoquinolinone displayed an absorption wavelength red-shifted from 470 to 540 nm (Delta lambda = 70 nm) with a color change from yellow to red, while the interaction between Fe3+ and 7-azaisoquinolinone was very weak and there was no obvious color change (Delta lambda = 18 nm). Moreover, theoretical calculations confirmed the different optical properties with 6- and 7-azaisoquinolinones.
Pyridinium-Fused Pyridinone: A Novel “Turn-on” Fluorescent Chemodosimeter for Cyanide
A new chemodosimeter based on pyridinium‐fused pyridinone iodide (PI) has been obtained through a “clean reaction” method. This compound can detect CN− in aqueous solution with a high selectivity and rapid response. The detection of CN− occurs through the nucleophilic attack of CN− on the CN bond, which induces the destruction of the π‐conjugation on the pyridinium ring. Support of this detection