Herein, facile synthesis and characterization of four Triazole linked Network Polymers (TNPs) in high yields is described. These nitrogen rich polymers are derived using "Click" reaction between 2,6,14triazido triptycene and various di or triethynyl comonomers. The TNPs are microporous and exhibit high surface area (SA BET up to 1348 m 2 g −1 ). Due to incorporation of 1,2,3-triazole motif (a CO 2 -philic moiety), the TNPs record moderate to high CO 2 uptake (upto 4.45 mmol/g at 273K and 1 bar). The TNPs also show very good CO 2 /N 2 (upto 48) and CO 2 /CH 4 (8 -9) selectivity. While highest storage capacity has been registered by TNP4 (CO 2 4.45 mmol/g at 273K and 1 bar, CH 4 23.8 mg/g, H 2 1.8 wt%), the highest CO 2 /N 2 and CO 2 /CH 4 selectivity was shown by TNP3 which contains additional nitrogen rich building blocks in the form of heteroaromatic pyrazine rings. These results suggest that TNPs are porous materials with potential practical application in gas storage and separation. Introduction:Design and syntheses of porous materials have attracted considerable research attention over the past decade. 1-4 In recent years, research output in this direction has witnessed considerable growth. 5-13 Depending on the pore size, porous materials may be classified as ultra-microporous 14-16 microporous, 12,13 mesoporous 17-19 or macroporous. 20,21 Among these, microporous materials have emerged as potential candidates for applications that include but are not limited to gas storage and separation. Microporous materials, such as zeolites 22,23 and metal-organic frameworks (MOFs), 1-5 contain metal atoms. Alternatively, microporous materials can also be designed in the form of metal-free organic polymers that are highly crosslinked. Acronyms such as COFs, CMPs, CTFs, EOFs, HCPs, MOPs, OCFs, PAFs, PIMs, POFs, POPs, PPFs, PPNs, etc have been coined to describe metal-free porous organic polymers. 6-13 In general, MOFs have limited industrial applications as porous materials because presence of relatively labile coordination bonds that lower their thermal stability. 24 On the other hand, in microporous organic polymers (MOPs), light weight elements (such as H, C, N, and O) are interlinked via relatively stronger covalent bonds. Therefore these metal-free materials have lesser mass densities and higher stabilities (chemical and thermal). In addition, MOPs can be easily tailored with respect to properties such as guest selectivity and pore properties, due to availability of a plethora of multifunctional organic molecules that can serve as monomers towards the syntheses of MOPs.In contemporary research dealing with development of microporous materials, design of MOPs for selective CO 2 capture and sequestration has received special attention. This has stemmed from environmental and energy concerns related to CO 2 , which is a major greenhouse gas. It is well known that thermal power plants emitting flue gas (containing approximately 15 % CO 2 ) are a major contributor to anthropogenic CO 2 . Therefore, in order to contain g...

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We report a facile synthesis of 2,6-diethynyltriptycene (DET) in high yield. Application of DET as monomer in polymer chemistry has been shown (for the first time) in syntheses of two novel polymers via Sonogashira cross-coupling reaction in high yield. The newly synthesized polymers were characterized by FT-IR, UV–vis absorption, and NMR spectroscopic techniques. The polymers prepared using DET have interesting properties such as high solubility in common organic solvents, high thermal stability [decomposition temperatures (T d) > 495 °C], and high char yield (greater than 81% at 900 °C). Additionally, polymers are fluorescent. Host–guest interaction between triptycene-based polymers and fullerene (C60) has been studied for the first time. Fluorescence quenching of our polymers by C60 has been used to study the extent of (polymer·C60) host–guest complex formation. Fluorescence quenching studies indicate binding constant for polymer·C60 complexation on the order of 105 M–1.

Two new triptycene-based azobenzene-functionalized polymers ( TBAFPs ) have been synthesized using the well-known Pd-catalyzed Sonogashira cross-coupling polycondensation reaction between 2,6-diethynyltriptycene and ( meta or para ) dibromo-azobenzenes. Enhancement of the fluorescent emission intensity was observed upon trans → cis isomerization of −N=N― linkage in TBAFPs . The cis-lifetime of TBAFP1 is rather long (greater than 2 days). The resulting materials were tested as a potential chemosensor for the detection of picric acid (PA)—a water pollutant as well as chemical constituent of explosives used in warfare. PA was found to interact strongly with TBAFPs , which led to significant quenching of the latter’s fluorescence emission intensities. The binding constants are in the order of 10 5 M –1 . TBAFPs were also able to detect PA in nanomolar concentrations.