Triarylboron‐Linked Conjugated Microporous Polymers: Sensing and Removal of Fluoride Ions

Abstract

A luminescent conjugated microporous polymer (BCMP-3) has been synthesized in high yield by a carbon-carbon coupling reaction using triarylboron as a building unit. BCMP-3 was fully characterized by using powder X-ray diffraction analysis, Fourier transform infrared spectroscopy, (13) C solid-state NMR spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, and nitrogen and carbon dioxide adsorption. The new three-dimensional conjugated framework possess a high Brunauer-Emmett-Teller (BET) specific surface area up to 950 m(2) g(-1) with a pore volume of 0.768 cm(3) g(-1) , good stability, and abundant boron sites in the skeleton. Under excited-light irradiation, BCMP-3 exhibits strong fluorescent emission at 488 nm with a high absolute quantum yield of 18 % in the solid state. Polymer BCMP-3 acts as a colorimetric and fluorescent chemosensor with high sensitivity and selectivity for F(-) over other common anions. In addition, the polymer also works as an adsorbent for F(-) removal and shows good adsorption capacities of up to 24 mg g(-1) at equilibrium F(-) concentrations of 16 mg L(-1) and a temperature of 298 K. The adsorption kinetics and isotherm were analyzed by fitting experimental data with pseudo-second-order kinetics and Langmuir equations. Furthermore, we highlight that BCMP-3 is an adsorbent for fluoride removal that can be efficiently reused many times without loss of adsorption efficiency.

Trends and challenges for microporous polymers

“…Two years later, Mu et al also coupled a less sterically encumbered tris(dimethylphenyl)borane building block to a triarylamine-based unit via Suzuki coupling. 189 The resulting polymer exhibited a surface area of 950 m 2 g À1 . It was found to act as a highly selective sensor towards fluoride over other common anions yet easily recyclable by stirring in THF solutions of BF 3 ÁOEt 2 as fluoride scavenger (Fig.…”

Electrochemically Generated Conjugated Microporous Polymer Network Thin Films for Chemical Sensor Applications

“…Maji et al and Mu et al. reported triarylborane‐cored CMPNs for selective fluoride ion sensing and capture . Xu et al.…”

“…Conjugated microporous polymer networks (CMPNs) have seen tremendous growth during last few decades and play vibrant roles in various fields of science and technology owing to their potential applications in gas storage/separation, heterogeneous catalysis, light emitting, light‐harvesting, optical sensing, and supercapacitors . Structural diversity of organic building blocks, accessible high surface area, and extraordinary chemical, thermal stability due to strong C–C linkages made them promising class of porous materials like zeolites, porous silicates, and metal–organic frameworks .…”

Imine‐linked porous organic polymers showing mesoporous microspheres architectures with tunable surface roughness

“…Great progress has been made in porous organic polymers (POPs) area in the last several decades . These fascinating functional materials offer great advantages due to their structural flexibility on molecular design and post modification, thus show promising applications in various fields such as gas adsorption and separation, organic catalysis, environmental remediation, and chemical sensing . According to the structural regularity, there are two types of POPs.…”