title: Azaisoquinolinones: N positions tell you different stories in their optical properties.
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.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Junbo
authors.initials: J
authors.lastname: Li
authors.forename: Junkuo
authors.initials: J
authors.lastname: Gao
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Weiwei
authors.initials: W
authors.lastname: Xiong
authors.forename: Qichun
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D055620:Optical Phenomena; D011789:Quantum Theory
chemical_list: D001372:Aza Compounds; D007546:Isoquinolines