Novel p-extended polycyclic chromenopyridines: Synthesis, DFT, electrochemical, and thermogravimetric evaluation

Polycyclic aromatic hydrocarbons (PAHs) doped with heteroatoms such as thiophene, carbazole, and boron-dipyrromethene (BODIPY) have attracted increased attention because of their excellent optoelectronic properties in addition to the robust skeletons required for the construction of efficient organic electronics. Herein, novel it-extended polycyclic chromenopyridines 3a-d, 5, and 7 were synthesized via base-catalyzed cascade reaction of 3-cyano-7,8-benzochromone 1 with acetonitrile derivatives 2a-d, ethyl chloroacetate 4, and phenylpyrazolone 6 in very good to excellent yields. Density functional theory (DFT) calculation and electrochemical evaluation of compounds 3a-d, 5, and 7 revealed a decreased energy gap (E-g) compared to the precursor 3-cyanochromone 1 indicating their superior semiconducting and light-harvesting abilities. In addition, the observed thermal stability of chromenopyridines 3a-d, 5, and 7 with maximum weight loss at temperatures between 301.72 and 557.28 ? qualified them for wide organic electronic applications.

Automated summary

In this study, heteroatom-doped polycyclic aromatic hydrocarbons with excellent optoelectronic properties were successfully synthesized through base-catalyzed cascade reaction. The synthesized compounds were found to have a decreased energy gap, indicating their potential in semiconducting and light-harvesting applications. Additionally, they exhibited good thermal stability, qualifying them for various organic electronic applications.