Outside Back Cover: Unlocking Strong Second‐Harmonic Generation in Deep‐UV‐Transparent Polar Organic Sulfonates Through Connectivity Regulation (Angew. Chem. Int. Ed. 7/2026)

A series of deep-ultraviolet-transparent organic sulfonates were designed and synthesized for high-performing optical nonlinearities, as reported by Chao Wu, Chi Zhang, and co-workers in their Research Article (e21786). Three key parameters including second-harmonic generation, bandgap, and birefringence were synchronously optimized in the polar organic sulfonate by employing a connectivity-regulation approach. The work highlights that structural connectivity change can profoundly influence key nonlinear optical properties.