A photoluminescent microporous metal organic anionic framework for nitroaromatic explosive sensing

Abstract

By using the octadentate ligand tetrakis [(3,5-dicarboxyphenoxy)methyl] methane (H 8 L), a rare (4,8)-scu type microporous coordination polymer, [In 2 L][NH 2 (CH 3 ) 2 ] 2 $(DMF) 4 (H 2 O) 16 , was synthesized and structurally characterized. The compound possesses an anionic three-dimensional open framework and exhibits permanent porosity with selective gas adsorption of CO 2 over CH 4 . It exhibited strong fluorescence emission upon excitation at RT, and a selective, efficient emission quenching response towards nitroaromatic explosives. Experimental section Materials and methodsAll reagents and solvents were purchased from commercial sources and used without further purication. Ligand H 8 L was prepared as described in ref. 10.Infrared spectra were obtained on a Bruker Vector 22 spectrophotometer with KBr pellets in the 4000-400 cm À1 region. Elemental analyses for C, H, and N were performed on an Elementar Vario MICRO analyzer. Thermogravimetric analysis (TGA) was carried out in a Perkin-Elmer thermal analyzer under nitrogen with a heating rate of 10 C min À1 . Powder X-ray diffraction (PXRD) patterns were collected with a scan speed of Scheme 1 Schematic structure of H 8 L.

Luminescent metal–organic frameworks for chemical sensing and explosive detection

“…Chen 16 upon the addition of different analytes (electron deficient or rich) in DMF. 130 As established previously, the short-ranged electron transfer between a sensory material and analyte largely determines the fluorescence response. Tuning the band structure of an LMOF to facilitate this process is an important and logical consideration for the design of an effective sensor.…”

Metal–organic frameworks based on flexible ligands (FL-MOFs): structures and applications

“…A highly porous FL-MOF {[In 2 (tdm)•(Me 2 NH 2 ) 2 ]•xsolvent} n has been prepared based on H 8 tdm. 94 The framework is comprised of octahedral and cuboctahedral cages, leading to high potential free volume of 65.1%. Activation by SCD drying, the framework shows a BET surface area of 1555 m 2 g -1 , a total pore volume of 0.62 cm 3 g -1 , a H 2 uptake of 1.49 wt % at 1 bar and 77 K and 3.05 wt % at 16 bar and 77 K. With the sample activated by evacuation at 80 o C overnight, by contrast, the framework shows a BET surface area of 752 m 2 g -1 and a pore volume of 0.612 cm 3 g -1 .…”

Metal–Organic Frameworks Constructed from d-Camphor Acid: Bifunctional Properties Related to Luminescence Sensing and Liquid-Phase Separation

“…[51][52][53][54][55][56][57][58][59] The intensity of the PL in 3 are largely dependent on the aromatics, exhibiting significant quenching behavior in the case of nitrobenzene, which may be related to the electron transfer from the electron-donating MOF to the highly electron-deficient nitrobenzene molecule upon excitation (Figure 4a). To examine sensitivity towards nitrobenzene in more detail, a batch of suspensions of 3 with gradually increasing nitrobenzene contents was prepared to monitor the emissive response ( Figure S7a).…”