Fluorescent OFF–ON polymer chemosensor bonded alternatively with 1,4-dioctyloxybenzene and (R,R)-salen for cascade Zn²⁺ and chiral recognition

Abstract

The synthesis of the chiral main chain polymers 1a–b bonded alternatively with (R,R)-salen and 1,4-dioctyloxybenzene has been described employing a palladium-catalyzed C–C cross-coupling reaction as the key step. They are soluble in common organic solvents and act as a highly selective ‘OFF–ON’ fluorescent chemosensors toward Zn²⁺. The resultant Zn(II)-polymer complexes exhibit significant chiral recognition toward (R)- and (S)-1-phenyl-N-[(pyridin-2-yl)methylene]ethanamines 9 under ambient conditions.