Troger's Base Research Articles

Nitrogen-Oxidized Tröger's Base Macrocyclic Arenes: Unprecedented Enantioselective Recognition in Water.

Achieving high enantioselectivity with synthetic receptors, particularly in water, remains a significant challenge despite the success seen in natural biological systems. In this study, we introduce a facile synthesis of Tröger's base (TB)-containing macrocyclic arenes (TBn), where TB units are linked via methylene bridges, providing the macrocycles with a rigid framework. Oxidation of enantiopure TBn yields corresponding chiral nitrogen oxides (TBnNO) with excellent water solubility, attributed to the high polarity of the N-O bond, surpassing the pH limitations of traditional ion-functionalized approaches. Remarkably, TBnNO exhibits exceptional enantioselective recognition toward a wide range of chiral guests in aqueous solution, achieving enantioselectivities as high as 41.0. The underlying mechanism involves a combination of hydrophobic interactions and steric effects caused by rigid chiral cavities. These findings highlight the potential of nitrogen-oxidized macrocycles as a transformative tool for supramolecular application in water.

Nitrogen‐Oxidized Tröger's Base Macrocyclic Arenes: Unprecedented Enantioselective Recognition in Water

AbstractAchieving high enantioselectivity with synthetic receptors, particularly in water, remains a significant challenge despite the success seen in natural biological systems. In this study, we introduce a facile synthesis of Tröger's base (TB)‐containing macrocyclic arenes (TBn), where TB units are linked via methylene bridges, providing the macrocycles with a rigid framework. Oxidation of enantiopure TBn yields corresponding chiral nitrogen oxides (TBnNO) with excellent water solubility, attributed to the high polarity of the N−O bond, surpassing the pH limitations of traditional ion‐functionalized approaches. Remarkably, TBnNO exhibits exceptional enantioselective recognition toward a wide range of chiral guests in aqueous solution, achieving enantioselectivities as high as 41.0. The underlying mechanism involves a combination of hydrophobic interactions and steric effects caused by rigid chiral cavities. These findings highlight the potential of nitrogen‐oxidized macrocycles as a transformative tool for supramolecular application in water.

TICT, and Deep-Blue Electroluminescence from Acceptor-Donor-Acceptor Molecules.

Donor-acceptor (D-A) materials based on butterfly-shaped molecules could inhibit exciton-migration-induced quenching due to molecular twist. To explore this attribute towards beneficial photophysical properties, three novel bipolar acceptor-donor-acceptor (A-D-A) molecules with triphenyl triazine end capping along with substitution ortho to the Tröger's base (TB) scaffold varying from H, Me, and F were explored. The installation of H/Me/F imparted an electron push-pull effect with concomitant maneuvering of photophysical properties. On increasing solvent polarity, a remarkable bathochromic shift with a significant decrease in emission efficiency was observed due to the twisted intramolecular charge transfer state (TICT). Emission enhancement in the ethylene glycol-water mixture and diminution in the THF-water mixture further confirmed the existence of TICT states in these TBs. The torsional dynamics in the excited state were also evidenced by the time-dependent density-functional theory (TD-DFT) calculations. Owing to the butterfly architecture of the TB that suppressed TICT, TB-Trzs exhibited a significant blue shift, accompanied by a favorable quantum yield in the solid state. Among the three compounds, Me-TB-Trz exhibited deep-blue photoluminescence and was explored as a dopant in organic light-emitting diodes (OLEDs) to obtain deep-blue electroluminescence of brightness 4128 cdm-2 and CIE coordinates of (0.16, 0.09).

V-shape Tröger's base-based organic solvent nanofiltration membranes for fast and precise molecular separation

Organic solvent nanofiltration (OSN) membranes with precise molecular-sieving performance have become increasingly important in chemical and pharmaceutical industries, desiring superior membranes with both high permeability and selectivity. Herein, the V-shape Tröger's base (TB) structure is incorporated in the polyamide network to engineer microporosity as well as the molecular-sieving performance of the thin-film composite (TFC) polyamide membrane for organic solvent nanofiltration (OSN). The TFC membrane containing the TB structure features a rigid and contorted chain structure, which affords high and stable methanol permeability in OSN applications. Furthermore, the H-bond interaction between the H of amide groups and N in TB reinforces the interchain interaction, endowing the membrane with a precise selectivity to organic solutes. The as-prepared TFC membrane demonstrated high methanol permeance of 16.6 L m−2 h−1 bar−1 and sieving performance to organic molecules with molecular weight cut-off (MWCO) down to 349 Da. Furthermore, the membrane demonstrates shape selectivity for organic solutes, exploiting the fine microporous structure. This study may provide insights into the molecular design of TFC membranes by finely tuning the molecular features for precise solute separations.

Tröger's Base-Embedded Pillararenes─Macrocycles with Both Fixed and Conformational Chirality.

Tröger's base-embedded pillararenes (P[1]TB[3]A), which combine Tröger's base (TB) with dialkoxybenzene units, were prepared via a fragment-coupling macrocyclization strategy. The TB unit in macrocycle P[1]TB[3]A provides a fixed chiral source, while 1,4-alkoxybenzene segments flip quickly to change their arrangement, which could provide reversible conformational chirality for those macrocycles. This rare example of macrocycles holding both fixed and conformational chirality lays a good foundation for expanding pillararenes using the fixed chiral source.

Chlorin spiro-Tröger's base as a prospective photosensitizer for photodynamic therapy of cancer

Octahydroxy bis-porphyrin Tröger's base (TB) and octahydroxy porphyrin-chlorin spiro-Tröger's base (spiroTB) derivatives were successfully prepared from their Ni(II) complexes utilizing an optimized demetalation method using H2SO4-TFA followed by demethylation via BBr3. The synthesized TB and spiroTB were then in in vitro experiments for their utility in photodynamic therapy (PDT) of cancer. Compared to temoporfin (mTHPC, Foscan®), the chlorin derivative used in PDT of cancer, TB and spiroTB were localized in lysosomes instead of the endoplasmic reticulum and were found to possess enhanced biocompatibility. Cell culture studies were performed on TRAMP-C2 (prostate cancer), HeLa (cervical cancer), and MRC-5 (non cancerous) cell lines. Both TB and spiroTB displayed negligible dark toxicity but increased production of reactive oxygen species (ROS) when illuminated. In addition, spiroTB displayed significant phototoxicity in TRAMP-C2 cells (IC50, light 0.7 μM after 24 h incubation). Despite the phototoxicity of spiroTB being lower than that of mTHPC (IC50, light 0.02 μM), due to the low dark toxicity (IC50, dark > 100 μM), the therapeutic factor of spiroTB (>150) is six times higher than that of mTHPC (25).

Soluble Troger’s base-based polybenzimidazoles containing naphthalene units with improved phosphoric acid tolerance for use as high-temperature proton exchange membranes

Most Troger's base (TB)-based polymers reported for high-temperature proton exchange membranes (HT-PEMs) exhibit low phosphoric acid (PA) tolerance due to excessive swelling in PA solution. In this work, a novel dicarboxylic acid monomer containing both naphthalene and TB units (TB-N-COOH) was successfully synthesized, and the corresponding TB-based PBI homopolymer (TB-N-HPBI) was prepared for HT-PEM fuel cells (HT-PEMFCs). In addition, naphthalene units were incorporated into TB-based PBI copolymers (TB-N-CoPBIs). The resulting TB-N-HPBI and TB-N-CoPBIs exhibited high molecular weight and excellent solubility in organic solvents (e.g., DMSO and NMP) because of the twisted TB units. The incorporated naphthalene units significantly improved the oxidative stability. More importantly, the existed naphthalene units in polymer backbones endowed the membranes with excellent PA tolerance capability because of the rigid structure and poor affinity to PA, which limited excessive swelling in 85 wt% PA solution and hence promoted acid uptake capability. Among of them, the TB-N-HPBI membranes showed ultrahigh PA uptake of 508.6%, and resulting in the proton conductivity of 201 mS cm−1 at 160 °C under non-humidity conditions, which are far superior to most reported TB-based polymer membranes. In addition, the maximum peak power density (H2/air) of 437.2 mW cm−2 was achieved. Our present work demonstrated that the incorporation of the naphthalene units into TB-based PBI significantly promoted the improvement of comprehensive performance for HT-PEMFCs.

AIE-active dyes based on Tröger's base: Synthesis and mechanochromic luminescence

Three fluorescent dyes (DI-TB, ICZ-TB and ITPA-TB) were synthesized based on 1,3-indindanedione substituted Tröger's base (TB). All the dyes exhibited AIE properties in the mixed system of chloroform and n-hexane. The compounds showed reversible MCL properties with obvious fluorescence changes, which were confirmed by XRD and DSC. The fluorescence of ITPA-TB showed high contrast (68 nm) before and after grinding, and the fluorescence changed from yellow (546 nm) to red (614 nm). In addition, the three solid compounds showed good thermal stability by thermogravimetric analysis. The TB dyes further opened up new ideas for the development of TB-based mechanochromic luminescent materials.

Preparation of porous organic cage and its use as chiral stationary phase for capillary electrochromatography

Porous organic cages (POCs) are a unique type of microporous materials composed of discrete molecules with internal cavities that are accessible to various compounds. In this study, a prismatic chiral POC with good thermochemical stability was synthesized by condensing (1R,2R)-diaminocyclohexane and 3,3',5,5'-teturonic-4,4'-biphenediol via the Schiff base reaction and characterized by proton nuclear magnetic resonance spectroscopy, infrared (IR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy. The IR spectrum of the POC revealed a strong characteristic absorption peak at 1635 cm-1, indicating that it formed imine bonds (C=N). The absorption peak at 3425 cm-1 was attributed to the stretching vibrations of -OH, the absorption peaks at 2925 and 2858 cm-1 were attributed to the stretching vibrations of N=C-H and C-H, and the absorption peaks at 1446 and 1383 cm-1 were attributed to the stretching vibrations of C=C-H and C=C in the benzene ring. High-resolution mass spectral analysis of the POC showed a molecular ion peak at m/z 1363.7228, indicating its successful synthesis. TGA was performed from 25 to 800 ℃ at a rate of 10 ℃/min, and the results of this analysis showed that the POC was stable up to approximately 300 ℃. The POC was dissolved in dichloromethane and uniformly coated on the inner wall of a quartz capillary via the dynamic coating method to prepare a capillary electrochromatographic column. The experimental results revealed that the chiral electrochromatographic column could not only resolve ofloxacin, Troger's base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol but also separate the isomers of o-, m-, and p-toluidine and o-, m-, and p-chloroaniline, indicating its good chiral separation ability. Investigation of the optimal separation conditions for ofloxacin, Troger's base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol revealed that the voltage, buffer solution concentration, and pH significantly affected their separation degree. In particular, the optimal separation voltage for ofloxacin, Troger's base, and 2-amino-1-butanol was 15 kV, while that for 1-phenyl-1-amyl alcohol was 17 kV. The optimal buffer concentration and pH for ofloxacin, Troger's base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol were 0.100 mol/L and 7.5. Under optimal chromatographic conditions, the resolution values for ofloxacin, Troger's base, 2-amino-1-butanol, and 1-phenyl-1-pentanol were 1.80, 3.33, 1.69, and 1.18, respectively. The results collectively demonstrate that the prepared POC may serve as a good chiral stationary phase for capillary electrochromatography with a certain chiral resolution ability and has good application prospects in chromatographic separation.

Tröger's base derived 3D-porous aromatic frameworks with efficient exciton dissociation and well-defined reactive site for near-unity selectivity of CO2 photo-conversion

The overall photocatalytic conversion of CO2 and H2O to fuel and O2 is challenging. In this study, a series of three-dimensional Tröger's base-derived porous aromatic frameworks (3D-X-TB-PAFs (X = TEPE, TEPM, SPF)) featuring designated reaction sites and unique charge transfer properties were developed. The incorporation of V-shaped Tröger's base (TB) units and aromatic alkynes imparts the polymers with permanent porosity, additional photon scattering cross-sections, and enhanced CO2 adsorption/activation capabilities. Density functional theory calculations and optoelectronic measurements revealed the formation of intramolecular built-in polarization and electron-trap sites induced by TB, which modulated charge separation and customized reaction sites in collaboration with 3D networks. In addition, product allocation during the photoreduction of CO2 was regulated by the photooxidation of H2O. Among the as-prepared 3D-PAFs, the most efficient electron transport channel was demonstrated by the TEPE-TB-PAF with fully conjugated TEPE-T. In the absence of cocatalysts and sacrificial agents, TEPE-TB-PAF exhibits a competitive CO formation rate (194.50 μmol g−1 h−1) with near-unity selectivity (99.74%). Significantly, the low energy barrier for CO desorption and the high energy barrier for *CHO formation contribute to the high efficiency of TEPE-TB-PAF, as demonstrated by computational exploration and in situ diffuse reflectance infrared Fourier transform spectra. This work offers efficient building blocks for the synthesis of multifunctional organic photocatalysts and groundbreaking insights into the simultaneous enhancement of photocatalytic reactivity and selectivity.

Azo‐bridged hydroxyl‐rich porous pillar[5]arene polymers for efficient carbon dioxide conversion

AbstractTwo new azo‐bridged hydroxyl‐rich porous organic polymers (POPs), named PPDA‐P5 and TB‐P5, were designed and successfully fabricated via azo‐coupling reaction with per‐hydroxylated pillar[5]arene macrocycle as the core and p‐phenylenediamine and Troger's base (TB) diamine as the linker, respectively. Owing to the abundant nitrogen and hydroxyl groups, both polymers exhibited excellent interaction affinity toward carbon dioxide (CO2) and then were applied as efficient heterogeneous catalysts for the transformation of CO2 to cyclic carbonates with high yield, even under mild conditions. Interestingly, TB‐P5 exhibited superior catalytic performance toward PPDA‐P5, indicating TB's positive role as an organic base. This design strategy and results provided new insight into the development of macrocycle‐based POPs in the field of heterogeneous catalysis.

Tröger's base-regulated interfacial polymerization of polyamide nanofiltration membranes with enhanced performance

Interfacially fabricated polyamide thin film composite (TFC) membranes have been widely used in molecular and ion nanofiltration. However, it is still a great challenge to desirably control the thickness and performance of polyamide layer due to the uncontrollable interfacial polymerization (IP) process. In this work, Tröger's base (TB), consisting of two benzene rings connected by a bicyclic aliphatic methanodiazocine unit was used to regulate the IP between trimesoyl chloride (TMC) and piperazine (PIP). The incorporation of TB molecule accelerates the diffusion rate of PIP toward the water/hexane interface and enhances the reaction activity of TMC as a catalyst, thus largely promoting the interfacial reaction rate and resulting in the formation of polyamide layer with an extremely thin thickness. The thickness of the polyamide layer was tuned from 63.1 to 17.4 nm by increasing the TB content in aqueous solution. The TFC nanofiltration membrane fabricated through TB regulated IP process showed a water permeance of 18.5 ± 1.4 L m−2 h−1 bar−1 and simultaneously a salt rejection of 98.3% for Na2SO4 with overall desalination performance exceeding most nanofiltration membranes and commercial membranes. This work proposes a strategy for regulating the reaction rate of PIP and TMC during the IP process using a TB structured additive, which provides an alternative means for fabricating highly permeable TFC nanofiltration membranes.

Tröger's Base-Based Cuboid Constructed by Chiral Self-Discrimination.

Cuboid, a basic geometric structure, has been widely applied in architecture and mathematics. In chemistry, the introduction of cuboid structures always provides a specific structural shape, enhances the stability of the structure and improves the performance of materials. Herein, a simple strategy exploiting self-discrimination to construct a cuboid-stacking crystal material is proposed, in which a chiral macrocycle (TBBP) based on Tröger's base (TB) and benzophenone (BP) was synthesized as the building element of the cuboid. The cuboid is designed to be transformable compared with cuboid structures in previous work. For this reason, it is considered that the cuboid-stacking structure can be transformed through external stimulation. Iodine vapor is selected as the external stimulus to transform the cuboid-stacking structure due to the favorable interaction between iodine and the cuboid. The changes in the stacking mode of TBBP is studied by single-crystal X-ray diffraction (SCXRD) and powder X-ray diffraction (PXRD). To our surprise, this Tröger's base-based cuboid shows strong iodine adsorption capacity up to 3.43 g g-1 and exhibits potential as a crystal material for iodine adsorption.

Insertion of pillar[5]arene into Tröger's base-derived porous organic polymer for promoted heterogeneous catalytic performance in Knoevenagel condensation and CO2 fixation

Development of new metal-free heterogeneous catalysts has long been the focus of intense research interest. The integration of multifunctional monomers into the skeletons of porous organic polymers (POPs) provides an efficient pathway to achieve this goal. Herein, we rationally designed and successfully prepared a new Tröger's base (TB)-derived POPs by insertion of pillar[5]arene macrocycle as a positively auxiliary group. Combined the both merits of pillar[5]arene macrocycle and TB moiety, the as-prepared polymer was further explored as an effective metal-free heterogeneous catalyst and exhibited promoted catalytic performance in Knoevenagel condensation and CO2 conversion. This work provides a new strategy to fabricate metal-free heterogeneous catalysts based on macrocyclic POPs.

Tailoring of microporosity of Tröger's base (TB) high temperature proton exchange membrane by miscible polymer blending

To further mitigate the phosphoric acid leakage in high temperature proton exchange membrane (PEM), the microporosity of Tröger's base (TB) membrane based on a V-shaped bridged bicyclic diamine has been fine-tailored readily by polymeric blending with a miscible polymer of intrinsic microporosity (PIM-1). As expected, the average cavity radius in the range of 3.46–4.21 Å has been achieved when the blending ratio of PIM-1 increases from 5 to 20 mol% due to the interaction between the amine group of TB and the nitrile group of PIM-1. The resulting PEMs show excellent PA retention ability. Notably, PIM/TB9 membrane with a suitable cavity radius of 3.5 Å and largest FFV4 of 49.1% exhibits an exciting PA retention of about 80%, which is much better than the pristine TB membrane. Thus, the remaining proton conductivity of PIM/TB9 is almost 5 times higher than that of TB membrane after 22 relative humidity cycle tests. Moreover, the resulting cell can run smoothly within a wide temperature range from 0 to 160 °C. The single cell performs for over 150 AST cycles and remains stable for >600 h with no visible voltage decay at 80 °C. Therefore, these results indicate the technical feasibility to improve the PA retention via fine-tuning the intrinsic microporosity of the PEMs through a direct blending method.

Ionization of Tröger's base polymer of intrinsic microporosity for high-performance membrane-mediated helium recovery

Tröger's base (TB) polymer of intrinsic microporosity has aroused increasing attention in various membrane-mediated gas separations. Herein we report macromolecular engineering to tune the microporosity of Tröger's base polymer of intrinsic microporosity (TB-PIM) via ionization for highly permselective helium recovery from natural gas. We reveal that the ionization of TB-PIM tightens polymer chain-packing, leading to dramatic enhancement of gas selectivities. Consequently, the ionic ITB-PIM membranes display the He/CH4 selectivity increments in the range of 34–158% and impressively high gas selectivities for helium recovery (i.e., α(He/CH4) = 246; α(He/N2) = 229). Due to the enhancement of inter-chain interactions induced by electrostatic interaction, the ITB-PIM membranes exhibit enhanced plasticization resistance compared to the pristine TB-PIM membranes. Notably, the ITB-Trip membrane showed excellent low-temperature gas separation performance with a He permeance of 3162 Barrer and He/CH4 selectivity of 38.5 at −30 °C, far beyond the 2008 upper bound. It is also proved that the microporosity and gas separation performance of ITB-PIM membranes is highly tailorable by adjusting the TB monomer structure. The facile functionalization method, highly diverse tunability, and excellent gas separation performance render the ITB-PIM membranes promising for helium recovery from natural gas.

Dibenzo-15-crown-5-based Tröger's Base membrane for 6Li+/7Li+ separation

The separation of lithium isotopes through membrane-based technologies has become an increasingly attractive research direction, considering the application of lithium isotopes as potential energy sources. However, the very similar physicochemical properties of 6Li+ and 7Li+ pose a significant challenge in developing capable membranes and the separation performance is currently not satisfactory. Here we report a dibenzo-15-crown-5-based polymeric membrane synthesized from Tröger's Base (TB) polymerization, namely PIM-DB15C5-TB, for lithium isotope separations. The introduction of dibenzo-15-crown-5 enables PIM-DB15C5-TB to manifest good 6Li+/7Li+ selectivity, and the TB units having rigid and contorted structure conformation provide PIM-DB15C5-TB with abundant free volumes for 6Li+/7Li+ transport. When applied in electrodialysis for the separation of 6Li+/7Li+, PIM-DB15C5-TB demonstrates a 6Li+/7Li+ selectivity of 1.16. The current work proposes a strategy for developing polymeric membranes for the selective separation of lithium isotopes.

Tröger's Base Chemistry in Solution and in Zr(IV)-Based Metal-Organic Frameworks.

Tröger's base (TB) and its derivatives have been studied extensively due to their unique concave shape stemming from the endomethylene strap. However, the strap-clipped TB chemistry has been largely overlooked in metal-organic framework (MOF) solids, leading to a gap in our knowledge within this field. In this work, we report the in situ strap elimination of a carboxylate-carrying TB in the presence of formic acid, both in solution and in Zr(IV)-based MOFs. In the solution system, the methanodiazocine nucleus can be exclusively transformed into an N,N'-diformyl-decorated phenhomazine derivative, regardless of the solvent used (DMF, DMA, or DEF), as unambiguously uncovered by single crystal X-ray crystallography. In contrast, while in the MOF synthetic system, the degree of derivatization reaction can be effectively controlled to give either the secondary diamine or formyl-decorated diamine, depending on the solvent used (DMF or DEF), resulting in the formation of two Zr-MOFs with 8-connected bcu (NU-1900) and 12-connected fcu (NU-407) topologies, respectively. The derivatization mechanism is proposed to be topology-guided and dependent on the local acid concentration during the MOF formation processes. Moreover, we discovered a novel post-synthetically water-induced in situ linker formylation process in NU-1900 through sequential formic acid elimination, migration, and condensation processes, affording an isostructural framework with the same linker as in NU-407, which further corroborates our proposed mechanism. Additionally, the highly defective NU-1900 with abundant accessible Zr sites was demonstrated to be an outstanding catalyst for the detoxification of a nerve agent simulant with a half-life of less than 1 min.

Corolliform morphology thin film composite polyamide membrane constructed via Tröger's base PIM for enhancing nanofiltration separation performances

In this study, a kind of Tröger's base (TB) polymer of intrinsic microporosity (PIM) was proposed to adjust both the micro-structure and macro-performance of the thin film composite (TFC) polyamide nanofiltration (NF) membrane. First, a rigidly-contorted Tröger's base (TB) diamine monomer — 2,8-diamino-4,10-dimethyl-6H,12H-5,11-methanodibenzo [1,5]-diazocine (TBDA) was synthesized (Yield: 90.2 %), and then was incorporated with piperazine (PIP) to react with trimesoyl chloride (TMC) monomer via the coupling of phase inversion and interfacial polymerization for constructing the TB-PIM-based polyamide (PA) selective separation layer. Especially, the NF membrane (TFC-TBDA/PIP) fabricated with 1/1 of TBDA/PIP and 0.075 (w/v) % TMC exhibited particular “corolla-like” morphology with high microporosity, thinner selective layer <55 nm. Under neutral condition, this membrane surface also is more negatively charged. These features further endowed this membrane superior permeability and selectivity. It showed about 2-fold water flux (87.67 L·m−2·h−1) of the conventional NF membrane (TFC-PIP) without sacrificing the multivalent sulfate salt rejections of Na2SO4 and MgSO4, and meanwhile the MgSO4 rejection was about 4.3 times as much as MgCl2. Moreover, the XPS results also revealed that there was nearly no chemical structure change of TB-PIM-based polyamide after acid soaking. Therefore, this study provides an effective way to fabricate the high-performance TFC nanofiltration membrane.

Hydrogen bonding-induced 6FDA-DABA/TB polymer blends for high performance gas separation membranes

To promote polyimide gas transport properties, we propose a facile technique through adjustable hydrogen bonding energy through blending polyimide (6FDA-DABA) containing –COOH groups and Tröger's base (TB) polymer without damaging polymer chemical structures. The hydrogen bonding strength between –OH groups in PI and the N atoms in TB (O–H⋯N) is well tailored via controlled thermal treatment which has been confirmed by molecular simulations. Hydrogen bonding amounts and strength reach maximum within membranes annealed at 120 °C for 16 h, and exhibit CO2/CH4 and H2/CH4 selectivities of 115.0 and 481.8 respectively, surpassing the 2008 upper bound. Contributed by the enhanced hydrogen bonding strength, the membranes annealed at 120 °C for 16 h display excellent CO2 plasticization resistance and physical aging in comparison with pristine PI and TB membranes. Such a approach potentially renders a synthetic membrane applicable for CO2 separation and hydrogen purification at high temperatures.