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

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.

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Chiral main chain polymer bonded alternatively with 1,4-dioctyloxybenzene and (R,R) salenMonomeric unit: C42H56N2O4[α]D20=-570 (c 0.02, CHCl3)Absolute configuration: (R,R)Source of chirality: (1R,2R)-1,2-Diaminocyclohexane

Chiral main chain polymer alternatively bonded with 1,4-dioctyloxybenzene and (R,R) salen.Monomeric unit: C50H58N2O4[α]D20=-126 (c 0.03, CHCl3)Absolute configuration: (R,R)Source of chirality: (1R,2R)-Diphenylethylenediamine