Upconversion Luminescence with Bis‐pyclen Yb(III) Chelates: Crown vs. Linear Polyether Linkers in Discrete Heteropolynuclear Architectures. - Hamon, Nadège; Godec, Léna; Sanchez, Samuel; Beyler, Maryline; Charbonnière, Loïc J.; Tripier, Raphaël (Angewandte Chemie International Edition, 2025)