Fluorene‐based conjugated polymer with tethered thymines: click postpolymerization synthesis and optical response to mercury(II)

Abstract

A kind of fluorene-based conjugated polymer with tethered thymine (T) groups {poly [(9,9-dioctyl)-2,7-fluorene-{9,9-dioctyl-4-1,2,3-triazol-[5-(hydroxymethyl)tetrahydrofuran-2-yl]-5-methylpyrimidine-2,4(1H,3H)-dione}-2,7-fluorene]-co-[(9,9-dioctyl)-2,7fluorene-4,7-bis(5-thiophen-2-yl)benzo-2,1,3-thiadiazole] (P-3)} was successfully synthesized by a Cu(I)-catalyzed click reaction between the acetylene-substituted polymer precursor {poly[(9,9-dioctyl)-2,7-fluorene-(9,9-dioctyl-4-phenylacetylene fluorene)]co-[(9,9-dioctyl)-2,7-fluorene-4,7-bis(5-thiophen-2-yl)benzo-2,1,3-thiadiazole]} and 3 0 -azido-3 0 -deoxythymidine. The chemical structures of the intermediates and target polymer were verified by Fourier transform infrared spectroscopy and 1 H-NMR analyses. The specific binding with Hg 2þ of P-3 was corroborated by ultraviolet-visible spectroscopy and photoluminescence analyses against other metal ions. The results show that P-3 possessed selectivity and sensitivity toward Hg 2þ . Around 77% of photoluminescence intensity of P-3 was quenched when the concentration of Hg 2þ reached 7.7 Â 10 À4 M and with a detection limit in the range of about 4.8 lM. A comparison experiment suggested that a synergic effect of the tethered T and S atoms interrelated with Hg 2þ existed in P-3. Most of the fluorescence intensity of P-3 was recovered upon the addition of iodide anions to the P-3/Hg 2þ complex; this suggested that P-3 could be used as a potential reversible optical Hg 2þ probe.

Sulfur-containing, triphenylamine-based red-emitting conjugated polymer/I− assembly as turn-on optical probe for mercury(II) ion

“…It is well known that there is also high affinity between Hg 2+ and sulfur, and several fluorescence turn-off mode, CPs-based Hg 2+ probes [18][19][20][21][22] have been designed by taking advantage of such typical Pearson's soft acids and bases interaction [38]. The result in our recent work about thymine-decorated, fluorene and DBT based CPs also revealed that the fluorescence of DBT and DBT-containing polymers will be quenched by the addition of Hg 2+ [39]. The apparent fluorescence enhancement in this effort reflects that the binding between I -and Hg 2+ is so strong that the fluorescence restored even with the coexistence of S atoms in the backbone of PFTD, this is to say that here the association between I -and Hg 2+ precedes that between S and Hg 2+ .…”

Barbituric acid–triphenylamine adduct as an AIEE-type molecule and optical probe for mercury(ii)

“…21,22 Various thymine-containing optical motifs have been successfully applied as probes for Hg 2+ . [23][24][25] The introduction of a thymine moiety into an optical platform has mainly been achieved through halogenalkyl-thymine-condensation 26,27 and click reactions, 28,29 and these methods suffer from relatively low reaction yields for the former, and tedious synthetic routes and the possibility of residual Cu-catalyst in the product for the latter. How to realize efficient preparation of thymine-decorated optical compounds via a simple preparation protocol is still a challenging task.…”

Synthesis, characterization, and Pb2+ ion sensing application of hexa‐armed dansyl end‐capped poly(ε‐caprolactone) star polymer with phosphazene core

“…5,8,9 According to the report of World Health Organization (WHO), Pb 21 ion concentration in drinking water must not exceed 10 lg L 21 . 1,13,14 The development of sensitive, robust, reliable, and portable analysis methods for the detection of metal ions has drawn a great deal of attention. 10,11 Hg 21 ions in the environment can be transformed into lipophilic organomercury derivatives (CH 3 HgX) and accumulates in the human body through the food chain.…”