- Salen-based enantiomeric polymers for enantioselective recognition
-
This paper describes how the spatial arrangement of the building blocks in a polymer chain influences the recognition properties of polymers. Here, we have designed and synthesized a series of fluorene based (A-B)n type salen polymers where the A-part is a fluorophore and the B-part is a recognition site using the condensation reaction of a fluorene based di(salicylaldehyde) compound (FSal) with diamines. Among the polymers, two are chiral (P1 and P2) which are enantiomeric (1R,2R vs. 1S,2S) to each other and three are achiral polymers (P3, P4 and P5). Circular dichroism studies of two chiral polymers reveal more or less equal and opposite CD intensities, indicating the induction of handedness in the polymer backbone. All polymers (P1-P5) contain the same recognition site but the spatial arrangements of the recognition sites are different from one another. We have studied the recognition properties of the polymers towards phenylglycinol. Only P1 and P2 exhibit good enantioselective recognition towards phenylglycinol through turn-on fluorescence enhancement because the microenvironment of the recognition sites is well organized to accommodate guest molecules. Three achiral polymers P3, P4 and P5 have no capacity to capture the guest molecules due to the lack of a suitable microenvironment at the recognition sites. This observation supports the phenomenon that the spatial arrangement of the building blocks in a main chain polymer determines its recognition properties. Moreover, P1 and P2 recognize the guest molecules through turn-on fluorescence (bright blue) in solution which gives a good platform for real application purposes.
- Bera, Manas Kumar,Chakraborty, Chanchal,Malik, Sudip
-
-
Read Online
- Highly emissive excited-state intramolecular proton transfer (ESIPT) inspired 2-(2′-hydroxy)benzothiazole-fluorene motifs: Spectroscopic and photophysical properties investigation
-
Tuning or switching of the solid state luminescence of organic materials is an attractive target for both basic research and practical applications. In the present study, solid state emissive compounds with very high quantum efficiencies (ΦF up
- Padalkar, Vikas S.,Sakamaki, Daisuke,Tohnai, Norimitsu,Akutagawa, Tomoyuki,Sakai, Ken-Ichi,Seki, Shu
-
p. 80283 - 80296
(2015/10/05)
-
- Fluorene-based chemodosimeter for "turn-on" sensing of cyanide by hampering ESIPT and live cell imaging
-
A new salicylaldehyde appended fluorene-based chemodosimeter (FSal) has been designed by taking consideration of the special nucleophilicity of cyanide ion. FSal shows selective affinity towards CN- over other anions (namely F-, Br-, NO3-, ClO 4-, N3-, H2PO 4-, AcO-, I-, Cl-, and NO2-) through turn-on fluorescence with a minimum detection limit of 0.06 ppm. The turn-on fluorescence of the FSal-CN complex resulting from hampering ESIPT is also supported by DFT and TDDFT calculations. Biological compatibility and live cell imaging of this unique probe have also been explored.
- Bera, Manas Kumar,Chakraborty, Chanchal,Singh, Pradeep Kumar,Sahu, Chandan,Sen, Kaushik,Maji, Samir,Das, Abhijit Kumar,Malik, Sudip
-
p. 4733 - 4739
(2014/07/21)
-