Cis/trans Fluorescent Recognition by Naphthalimide Dyes ⊂ CB [7] Assembly.

A novel method to recognize cis/trans isomers was studied here. The naphthalimide dye as guest could bind with host cucurbit [7]uril (CB [7]) and 1:1 naphthalimide dye âŠ‚ CB [7] assembly was formed. Moreover, this assembly was used as a fluorescent probe to recognized Fumaric acid (FA) and maleic acid (MA) via fluorescence titration. Two carboxyls in MA are in the same side, they could form stable interaction with the assembly and the fluorescence intensity decreased obviously when naphthalimide dye âŠ‚ CB [7] was titrated by MA (nearly quenched in 1.5 equiv). But two carboxyls in FA are in opposite sides, the interaction between FA and the assembly was weak and not stable, and the fluorescence intensity changed inconspicuously when the assembly was titrated by FA.

Synthesis of Schiff base-Based 1,2,4-Oxadiazole Derivative as Fluorescence Turn-On Sensor for High Selectivity of Pb(2.).

A new probe based on oxadiazole derivative (OXD) containing Schiff base moiety was synthesised as fluorescence turn-on sensor S1 . Furthermore, its fluorescents spectra (FS) result demonstrate that S1 selectively senses bivalent lead ion (Pb(2+)) in HEPES buffer solution (10 mM, pH = 7.0,DMF-H2O, 9:1, v/v), so S1 was a viable candidate as fluorescent receptor for a new Pb(2+) sensor. And the results of fluorescent spectral titration showed this sensor formed 1:1complex with Pb(2+).