Structural Dependence of the Selectivity of Fluorescent Chemosensors to Mg2+ from Alkali Earth Metal Ions

A series of novel 2,2′‐bipyridylene‐containing conjugated polymers are synthesized through the Wittig reaction. Some of these polymers show a highly selective affinity toward Mg²⁺ in a mixture of alkaline earth metal ions, which is different from the 2,2′‐bipyridylene‐containing poly(phenylene vinylene) derivatives reported previously. This is the first case to demonstrate that some materials show a selectivity toward Mg²⁺. The structures of the polymers may play a crucial role for this selectivity.