Simultaneous deconstructive ring-opening and skeletal reconstruction of an inert, aromatic pyridinium ring is of great importance in synthetic communities. However, research in this area is still in its infancy. Here, a skeletal re-modeling strategy was developed to transform chalcone-based pyridinium salts into structurally intriguing polycyclic isoindolines through a dearomative ring-opening/ring-closing sequence. Two distinct driving forces for the deconstruction of the pyridinium core were involved in these transformations. One was the unprecedented harnessing of the instability of in situ generated cyclic β-aminoketones, and the other was the instability of the resultant N,N-ketals. The desired isoindoline polycycles could undergo the Wittig reaction with various phosphorus ylides to achieve structural diversity and complexity. Notably, by tuning the Wittig conditions by addition of one equivalent of base, an additional bridged ring was introduced. A plausible mechanism was proposed on the basis of control experiments and theoretical calculations.

In this work, a new series of coordination polymers (CPs) 1–8 were designed and successfully synthesized; they displayed typical afterglow at room temperature under ambient conditions. In 1–4, single green phosphorescence was observed, where the T₂ (π, π*) state was stabilized by the π-stacking interactions of the phosphorescent group tynca⁻, which contributed to enhancing their luminescence lifetimes. In contrast, when the π-stacking interaction of the phosphorescent group tynca⁻ was absent in the rigid matrix, 5–8 exhibited an intriguing time-resolved afterglow modulation, in which yellow [T₁ (n, π*), short lifetime] and green [T₂ (π, π*), long lifetime] phosphorescences were sequentially observed during the decay process when the common UV light was turned off. As one of the representatives of long-lived dual phosphorescent CPs, the promising optical properties of 8 allowed it to be used in logos for advanced anti-counterfeiting systems. To the best of our knowledge, this special and rare afterglow modulation has not been reported in the literature for persistent RTP (p-RTP) CP systems, and further exploration in this area may open a new door for newly emerging technologies such as optical recording and encryption or multimodal bio-imaging.