Dicarboxylic ligands directing two Zn(II)-organic frameworks with distinct structures and significantly enhanced luminescence detection performances

Choosing different dicarboxylic ligands to construct MOFs with different structures and significantly improved luminescence detection properties has been studied. [Zn(L)(BDC)] n ( 1 ), [Zn 4 (L) 4 (ISO) 4 ] n ( 2 ) (L = 1,4-Bis(4-pyridyl)naphthalene, H 2 BDC = terephthalic acid , H 2 ISO = isophthalic acid) have been successfully synthesized and characterized. Their structural features vary from a 3D pillar-layered 5-fold interpenetrated dia framework ( 1 ) to a 2D double-layered non-interpenetrated sql net ( 2 ). The different structures between 1 and 2 can be attributed to distinct bridging angles from dicarboxylic ligands. Furthermore, luminescent sensing experiments exhibit that 1 and 2 are efficient dual-responsive sensors for the detection of acetylacetone (acac) and Cr 2 O 7 2− . Especially, 2 performs very highly sensitive quenching response towards acac in aqueous medium . More interestingly, 2 exhibits significantly enhanced quenching efficiencies than 1 (K sv of detecting acac: 7.87 × 10 3 M −1 for 1 and 4.9 × 10 4 M −1 for 2 ; K sv of detecting Cr 2 O 7 2− : 3.95 × 10 3 M −1 for 1 and 1.41 × 10 4 M −1 for 2 ). The cause for higher quenching efficiencies of 2 has been preliminary discussed. The efficient luminescence quenching mechanisms of 1/2 towards acac/Cr 2 O 7 2− have been elucidated. Dicarboxylic ligands with distinct bridging angles direct two Zn(Ⅱ)-MOFs with different structures and significantly improved luminescence detection properties. • Dicarboxylic ligands with distinct bridging angles direct two Zn(Ⅱ)-MOFs with different structures and luminescence detection properties • 1 And 2 show efficient luminescent dual-responsive sensing towards acac and Cr 2 O 7 2− in aqueous media. • 2 Perform very highly sensitive quenching response towards acac. • 2 Exhibits significant enhanced quenching efficiencies compared to 1. •The sensing mechanisms towards acac and Cr 2 O 7 2− were studied as well.