A metal-free approach for the synthesis of p-terphenyls 7 a–i and cyclic p-terphenyls 9 a–d and 11 a–d is described via carbanion induced ring transformation reaction of 6-biphenyl-2H-pyran-2-ones 5 with malononitrile 6, cyclohexanone 8 and 1,4-cyclohexanedione monoethylene ketal 10 respectively. Additionally, the base-mediated ring transformation reactions were working smoothly under mild reaction conditions and ring transformation products 7, 9 and 11 were isolated in good to excellent yields. The synthetic approach provides the flexibility of introducing of both electron-withdrawing and -donating functionalities in p-terphenyl architecture. Moreover, the photo physical properties of compounds 7, 9 and 11 were analyzed using UV-visible and Fluorescence Spectroscopy. p-Terphenyls 7 c showed cyan fluorescence in chloroform (λmax (em): 508 nm) and acetonitrile (λmax (em): 420 nm) while cyclic p-terphenyl 9 a showed blue fluorescence in chloroform and 1,4-dioxane (λmax (em): 470 nm). Similarly, compound 11 a showed blue fluorescence in chloroform (λmax (em): 468 nm) and 1,4-dioxane (λmax (em): 473 nm). Additionally, the thermal stability of synthesized cyclic p-terphenyls 11 a, 11 c and 11 d were also studied using TG and DTA techniques. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim