Multiple Hydrogen-bonding Interactions Research Articles

Supramolecular Annihilator with DPA Parallelly Arranged by Multiple Hydrogen-Bonding Interactions for Enhanced Triplet-Triplet Annihilation Upconversion.

The triplet annihilator is a critical component for triplet-triplet annihilation upconversion (TTA-UC); both the photophysical properties of the annihilator and the intermolecular orientation have pivotal effects on the overall efficiency of TTA-UC. Herein, we synthesized two supramolecular annihilators A-1 and A-2 by grafting 9,10-diphenylanthracene (DPA) fragments, which have been widely used as triplet annihilators for TTA-UC, on a macrocyclic host-pillar[5]arenes. In A-1, the orientation of the two DPA units was random, while, in A-2, the two DPA units were pushed to a parallel arrangement by intramolecular hydrogen-bonding interactions. The two compounds showed very similar photophysical properties and host-guest binding affinities toward electron-deficient guests, but showed totally different TTA-UC emissions. The UC quantum yield of A-2 could be optimized to 13.7% when an alkyl ammonia chain-attaching sensitizer S-2 was used, while, for A-1, only 5.1% was achieved. Destroying the hydrogen-bonding interactions by adding MeOH to A-2 significantly decreased the UC emissions, demonstrating that the parallel orientations of the two DPA units contributed greatly to the TTA-UC emissions. These results should be beneficial for annihilator designs and provide a new promising strategy for enhancing TTA-UC emissions.

Asymmetric Synthesis of Hydroindoles via Desymmetrizing [3+2] Annulation of p-Quinamines and Arylalkylketenes.

The asymmetric desymmetrizing [3+2] annulation reaction of p-quinamines and arylalkylketenes to synthesize hydroindoles was realized. Catalyzed by chiral bisguanidinium hemisalt via multiple hydrogen bond interactions, enantiomerically enriched products with reversal of diastereoselectivity in comparison with the racemic version were afforded in good yields under mild reaction conditions. Diaryl-substituted hydroindoles could also perform the Friedel-Crafts type of addition to give more complicated multicycles. Density functional theory calculations revealed that the enantio- and diastereoselectivity stem from varied hydrogen-bonding manners.

Crystallization manipulation of poly(butylene succinate) via hydrazide-based self-assembled hydrogen-bonding interactions

Self-assembled nucleating agents based on hydrogen bonding interactions have been increasingly used to manipulate the crystallization behavior of polymer materials, yet the specific working mechanism is not well unrevealed. In this study, the hydrazide-based nucleator structure of bis-(mono-methyl succinyl)dihydrazide (MSAD) is randomly incorporated in poly(butylene succinate) (PBS) chains to prepare a series copolymers of PBS-co-MSAD. It is confirmed that the multiple hydrogen-bonding interactions strengthen as the content of the MSAD segment increases, leading to a remarkable elevation of crystallization temperature. Meanwhile, the primary nucleation density of PBS is significantly raised without changing crystal modification. The formation of a pre-ordered network of hydrogen-bonding structures during non-isothermal crystallization is confirmed by rheological measurement and Fourier transform infrared spectroscopy investigation, which immediately induces the crystallization of PBS segments once strong enough. In addition, the melt crystallization mechanism of PBS-co-MSAD with heterogeneous hydrogen-bonding segments is elucidated in detail by combining a self-nucleation protocol.

Highly Stable O‐Tolylbiguanide‐CsPbI3 Quantum Dots and Light‐Emitting Diodes by Synergistic Supramolecular Passivation

AbstractDeveloping effective strategy to passivate surface defects in quantum dots (QDs) is critical to achieving high‐efficiency and long‐life perovskite light‐emitting diodes (LEDs). Here, the supramolecular interaction underpinning of organic‐inorganic components is exploited and a facile method is proposed to generate multiple‐hydrogen‐bonded supramolecular‐perovskite crystal structures on QD surfaces by introducing O‐Tolylbiguanide (O‐Tg) during QD synthesis, enabling bright, conductive, and water‐resistant CsPbI3 QDs. Compared with commonly used oleic acid and oleylamine ligands, the biguanide functional group in O‐Tg not only forms multiple hydrogen bond interactions with lead halide octahedra passivating both bridging‐ and terminal‐halogen ion defects, but also compatibly occupies the A‐site position stabilizing the crystal structure simultaneously. With fewer nonradiative defects and introduced hydrophobic benzene rings preventing eroding of polar molecules, CsPbI3 QDs exhibit remarkable photoluminescence quantum yields of 96%, and their film can be submerged in water for 30 h without degrading. The corresponding LEDs display a high external quantum efficiency (21.2%) and offer superior operational stability with a lifetime (T90) of 25 h at a constant current density as high as 50 mA cm−2.

Metal- and alkali-free aerobic oxidation of 5-hydroxymethylfurfural to 5-formyl-2-furancarboxylic acid facilitated by the multiple hydrogen bond interactions in the deep eutectic solvent

The oxidation of 5-hydroxymethylfurfural (HMF) to produce high value-added 5-formyl-2-furancarboxylic acid (FFCA) represents a promising biomass conversion reaction that holds potential for biomass-based material for the drug synthesis and polyester industry. The present study presents a metal-free and alkali-free catalytic system consisting of N-hydroxyphthalimide (NHPI) as an organic molecule and a deep eutectic solvent (DES). This system was successfully employed for the aerobic oxidation process of HMF to FFCA, demonstrating exceptional catalytic activity with 100% conversion and 96% FFCA yield in the absence of any alkali. Multiple hydrogen bond interactions were found to be indispensable and play a crucial role in promoting the catalytic process. These H-bond interactions serve three essential purposes: facilitating the formation of deep eutectic solvents (DESs) between polyethylene glycol and tetrabutylammonium chloride, accelerating the dissolution and activation of HMF, and aiding in the generation of active free radicals for NHPI. This work demonstrated the predominant oxidation ability of the NHPI-DESs system for the oxidation of HMF to FFCA through hydrogen bond interaction, thereby offering invaluable insights into the aerobic oxidation processes involving hydrocarbons or alcohols.

Multiarmed Aromatic Ammonium Salts Boost the Efficiency and Stability of Inverted Organic Solar Cells.

Inverted organic solar cells (OSCs) have attracted much attention because of their outstanding stability, with zinc oxide (ZnO) being commonly used as the electron transport layer (ETL). However, both surface defects and the photocatalytic effect of ZnO could lead to serious photodegradation of acceptor materials. This, in turn, hampers the improvement of the efficiency and stability in OSCs. Herein, we developed a multiarmed aromatic ammonium salt, namely, benzene-1,3,5-triyltrimethanaminium bromide (PhTMABr), for modifying ZnO. This compound possesses mild weak acidity aimed at removing the residual amines present within ZnO film. In addition, the PhTMABr could also passivate surface defects of ZnO through multiple hydrogen-bonding interactions between its terminal amino groups and the oxygen anion of ZnO, leading to a better interface contact, which effectively enhances charge transport. As a result, an efficiency of 18.75% was achieved based on the modified ETL compared to the bare ZnO (PCE = 17.34%). The devices utilizing the modified ZnO retained 87% and 90% of their initial PCE after thermal stress aging at 65 °C for 1500 h and continuous 1-sun illumination with maximum power point (MPP) tracking for 1780 h, respectively. Importantly, the extrapolated T80 lifetime with MPP tracking exceeds 10 000 h. The new class of materials employed in this work to modify the ZnO ETL should pave the way for enhancing the efficiency and stability of OSCs, potentially advancing their commercialization process.

Study of molecular mechanism and extraction performance evaluation for separation of phenolics from alkaline wastewater through synergistic extraction

ABSTRACT Phenols were a kind of pollutant in coal chemical wastewater with high concentration and difficult to decompose and have a significant impact on the subsequent biochemical treatment of the wastewater. In addition, phenols were a kind of weak electrolytes that partially dissociation oxidation under weakly alkaline conditions, making recovery more difficult. In order to solve this problem, phenols were extracted from weak alkaline wastewater with a synergistic solvent. First, the interaction between solvents and phenols and the solvent effect of solvents were calculated by quantum chemistry and the synergistic extractant cyclohexanone/1-pentanol was determined to have significant advantages. Moreover, the synergistic extractant was further analyzed through independent gradient model based on Hirshfeld partition analysis, atoms in molecule topology analysis, electrostatic potential analysis. Results indicated that the synergistic extract can provide multiple hydrogen bond interactions with phenol due to the double action sites of the C=O group of ketone and the -OH group of alcohol. In addition, the efficacy of the extractant was validated by multistage extraction, indicating partial dissociation oxidation of hydroquinone to benzoquinone under weakly alkaline conditions, with removal rates of 99.5% and 99.2% for phenol and hydroquinone, respectively. In general, the synergistic extractant can effectively remove phenols.

Luminescent Porous Organic Crystals for Adsorptive Separation of Toluene and Methylcyclohexane.

A butterfly-shaped phenothiazine derivative, PTTCN, was synthesized to obtain pure organic porous crystals for the highly efficient absorptive separation of toluene (Tol) and methylcyclohexane (Mcy). Due to the presence of three polar cyano groups and nonplanar conformation, these molecules self-assembled into a hydrogen-bonded organic framework (X-HOF-5) with distinct cavities capable of accommodating Tol molecules through multiple hydrogen-bonding interactions. Upon solvent removal via heating, the activated X-HOF-5 retained its cavity structure albeit with altered stacking arrangements, accompanied by a remarkable fluorescent color change from cyan to green. X-HOF-5a can undergo a phase transformation into X-HOF-5 upon reabsorption of Tol, while exhibiting no accommodation of Mcy due to the weak intermolecular interaction between PTTCN and Mcy. This suggests that the activated HOF material prefers Tol over Mcy. Moreover, X-HOF-5a may selectively accommodate Tol in a Tol/Mcy equimolar mixture, and the purity of Tol can reach 97% after release from the framework. Additionally, it is noteworthy that the HOF material exhibits recyclability without any discernible loss in performance.

Soybean oil-based random copolymers based on hydrogen bond crosslinked networks as reprocessable, recyclable and multifunctional adhesive materials

Adhesive industry transformation toward a formaldehyde-free and pollution-free society demands adhesive materials to be reprocessable and recyclable in circularity in an efficient and green manner. Recent advances in adhesive material have bestowed random copolymer such as vitrimer with reprocessability and recyclability, providing a way for the circular manufacturing of adhesive materials. However, reprocessability and recyclability of mechanically robust vitrimers typically requires high temperatures, high pressure and long processing time, which leads to lower practicability and economy of adhesive material. Here, a series of soybean oil-based polymers (SOPs) based on hydrogen bond crosslinked networks were fabricated by random polymerization via a solvent-free curing strategy under ultraviolet (UV) irradiation, and used as adhesive material. The introduction of multiple hydrogen bond interactions with reversible dissociation and association effects provide materials with adjustable mechanical strength, self-healing, adhesion and shape memory properties. Glass transition temperature of the polymers was manipulated via changing the ratio of soybean oil-based monomers (SOMs) and allyl thiourea. SOPs can effectively adhere to wood, metal, rubber, glass and PTFE. The dry shear strengths of wood substrate and steel substrate were 2.21 MPa and 2.06 MPa. SOPs based on multiple hydrogen bonds showed excellent self-healing and could be used to repair balloons and tires, etc. SOPs/carbon nanotubes (CNTs) composites exhibited adjustable electrical conductivity and was used as electric conductive adhesive. This work provided a facile and sustainable strategy to fabricate multi-functional and recyclable soybean oil-based adhesive, and SOPs/CNTs composites with outstanding electrical conductivity broadened their applications.

A Metal-Free Helical Covalent Inorganic Polymer: Preparation, Crystal Structure and Optical Properties.

Helical morphologies are widely observed in nature, however, it is very challenging to prepare artificial helical polymers. Especially, precisely understanding the structure information of artificial metal-free helical covalent inorganic polymers via single-crystal X-ray diffraction (SCXRD) analysis is rarely explored. Here, we successfully prepare a novel metal-free helical covalent inorganic polymer ({[Te(C6 H5 )2 ] [PO3 (OH)]}n , named CityU-10) by introducing angular anions (HOPO3 2- ) into traditional tellurium-oxygen chains. The dynamic reversibility of the reaction is realized through the introduction of organic tellurium precursor and the slow hydrolysis of polyphosphoric acid. High-quality and large-size single crystals of CityU-10 have been successfully characterized via SCXRD, where the same-handed helical inorganic polymer chains form a pseudo-two-dimensional layer via multiple hydrogen-bonding interactions. The left-handed layers and right-handed layers alternatively stack together through weak hydrogen bonds to form a three-dimensional supramolecular structure. The single crystals of CityU-10 are found to display promising optical properties with a large birefringence. Our results would offer new guidelines for designing and preparing new crystalline covalent polymers through tellurium-based chemistry.

Highly efficient deterpenation of essential oils in ionic porous organic polymers through multiple hydrogen-bonding interactions

Separation of the small amount of multi-component oxyterpenes over terpenes is imperative to improve the quality of essential oils, but challenging owing to their close molecular structure and similar properties. In this work, a new class of ionic polymers P(Aryl-Im-BCMBP) are constructed by employing well-designed monomer and crosslinker through a “one-pot two-step” strategy. The obtained polymers, combining multiple hydrogen-bonding sites and well-developed porosity, achieve excellent oxyterpene adsorption capacity (454.5 mg·g−1 citral or 352.1 mg·g−1 linalool), 2.1–5.0 times higher oxyterpene/terpene separation selectivity than commercial adsorbents and good liquids breakthrough performance. Quantum chemistry calculation results demonstrate that the multiple hydrogen-bonding interactions between ionic site and oxyterpene play an important role for selective oxyterpene adsorption. This study may shed light on the separation of high value-added structurally similar natural products.

Precise Methylation Yields Acceptor with Hydrogen-Bonding Network for High-Efficiency and Thermally Stable Polymer Solar Cells.

Utilizing intermolecular hydrogen-bonding interactions stands for an effective approach in advancing the efficiency and stability of small-molecule acceptors (SMAs) for polymer solar cells. Herein, we synthesized three SMAs (Qo1, Qo2, and Qo3) using indeno[1,2-b]quinoxalin-11-one (Qox) as the electron-deficient group, with the incorporation of a methylation strategy. Through crystallographic analysis, it is observed that two Qox-based methylated acceptors (Qo2 and Qo3) exhibit multiple hydrogen bond-assisted 3D network transport structures, in contrast to the 2D transport structure observed in gem-dichlorinated counterpart (Qo4). Notably, Qo2 exhibits multiple and stronger hydrogen-bonding interactions compared with Qo3. Consequently, PM6 : Qo2 device realizes the highest power conversion efficiency (PCE) of 18.4 %, surpassing the efficiencies of devices based on Qo1 (15.8 %), Qo3 (16.7 %), and Qo4 (2.4 %). This remarkable PCE in PM6 : Qo2 device can be primarily ascribed to the enhanced donor-acceptor miscibility, more favorable medium structure, and more efficient charge transfer and collection behavior. Moreover, the PM6 : Qo2 device demonstrates exceptional thermal stability, retaining 82.8 % of its initial PCE after undergoing annealing at 65 °C for 250 hours. Our research showcases that precise methylation, particularly targeting the formation of intermolecular hydrogen-bonding interactions to tune crystal packing patterns, represents a promising strategy in the molecular design of efficient and stable SMAs.

Supramolecular Detection of a Sub-ppm Nerve Agent Simulant by a Smartphone Tool.

The widespread use of smartphones and related tools is extending their applications in several fields. Herein, we report a reusable smartphone coupled portable detection system for the sensing of sub-ppm level of a nerve agent mimic (dimethylmethylphosphonate) in the gas phase. The detection system is based on multiple hydrogen-bond interactions of the vapor analyte with an ad-hoc functionalized Bodipy chromophore scaffold. The multitopic approach used for the molecular recognition of DMMP leads to the highest binding constant values, high selectivity, and low limits of detection.

A Closed Cavity Strategy for Selective Dipeptide Binding by a Polyaromatic Receptor in Water.

Precise recognition of peptides is a daunting task owing to the substantial number of available amino acids and their combination into various oligo/polymeric structures in addition to the high hydration of their flexible frameworks. Here, we report the selective recognition of a dipeptide through a closed cavity strategy, in contrast to previous synthetic receptors with open cavities. A polyaromatic receptor with a virtually isolated, hydrophobic cavity exclusively binds one molecule of phenylalanine dipeptide from a mixture with its amino acid and tripeptide in water via multiple CH-π and hydrogen-bonding interactions in the complementary cavity. The binding selectivity persists even in the presence of other dipeptides, such as leucine-leucine, leucine-phenylalanine, tyrosine-phenylalanine, tryptophan-tryptophan, and aspartame, revealed by NMR/MS-based competitive binding experiments. ITC studies reveal that the selective binding of the phenylalanine dipeptide is relatively strong (Ka = 1.1 × 105 M-1) and an enthalpically and entropically favorable process (ΔH = -11.7 kJ mol-1 and TΔS = 17.0 kJ mol-1). In addition, the present receptor can be used for the emission detection of the dipeptide through a combination with a fluorescent dye in water.

Polydopamine functionalized stellate mesoporous silica using mussel inspired chemistry for ultrastretchable, conductive and self-healing hydrogel on wearable strain sensors

Conductive hydrogels hold great promise in wearable strain sensor for human motion detection. Nevertheless, the poor mechanical properties, inferior sensitivity and the deficiency of multifunctionalities of conventional hydrogels tremendously constrain their applications. Herein, inspired by mussel chemistry, polydopamine (PDA) and Au nanoparticles (Au NPs) were used to modify stellate mesoporous silica (STMS), which could provide conductivity and multiple non-covalent interactions. The synthesized STMS@PDA-Au NPs were further used to prepare composite polyacrylic acid (PAA) hydrogel (STMS@PDA-Au NPs/PAA) by a one-pot strategy for the application of motion sensors. The resulting hydrogel exhibited satisfactory stretchability (663%), remarkable tensile strength (2.18 MPa), high sensitivity (Gauge Factor = 2.86) and distinguished self-healing properties (90.8%), which are believed to be contributed by the existence of coordination complexations and multiple hydrogen-bonding interactions in the hydrogel network. Additionally, with a rapid dynamic response time (180 ms) and fatigue resistance, this work provides useful insights as a wearable sensor for epidermal sensing applications.

Highly Stretchable, Self-Healing, Injectable and pH Responsive Hydrogel from Multiple Hydrogen Bonding and Boron-Carbohydrate Interactions.

A simple and cost-effective method for the fabrication of a safe, dual-responsive, highly stretchable, self-healing and injectable hydrogel is reported based on a combination of dynamic boronate ester bonds and hydrogen bonding interactions. The mechanical properties of the hydrogel are tunable by adjusting the molar ratios between sugar moieties on the polymer and borax. It was remarkable to note that the 2:1 ratio of sugar and borate ion significantly improves the mechanical strength of the hydrogel. The injectability, self-healing and stretchability properties of the hydrogel were also examined. In addition, the impact of the variation of the pH and the addition of free sugar responsiveness of the hydrogel was studied. High MRC-5 cell viability was noticed by the 3D live/dead assay after 24 h cell culture within the hydrogel scaffold. Hence, the developed hydrogels have desirable features that warrant their applications for drug delivery, scaffolds for cell and tissue engineering.

Synergistic effects of multiple rotors and hydrogen-bond interactions lead to sensitive near-infrared viscosity probes for live-cell microscopy

Synergistic effects of multiple rotors and hydrogen-bond interactions lead to sensitive near-infrared viscosity probes for live-cell microscopy

Bioinspired, Anticoagulative, 19 F MRI-Visualizable Bilayer Hydrogel Tubes as High Patency Small-Diameter Vascular Grafts.

The clinical patency of small-diameter vascular grafts (SDVGs) (ID < 6mm) is limited, with the formation of mural thrombi being a major threat of this limitation. Herein, a bilayered hydrogel tube based on the essential structure of native blood vessels isdeveloped by optimizing the relation between vascular functions and the molecular structure of hydrogels. The inner layer of the SDVGs comprises a zwitterionic fluorinated hydrogel, avoiding the formation of thromboinflammation-induced mural thrombi. Furthermore, the position and morphology of the SDVGs canbe visualized via 19 F/1 H magnetic resonance imaging. The outer poly(N-acryloyl glycinamide) hydrogel layer of SDVGs provides matched mechanical properties with native blood vessels through the multiple and controllable intermolecular hydrogen-bond interactions, which canwithstand the accelerated fatigue test under pulsatile radial pressure for 380 million cycles (equal to a service life of 10 years in vivo). Consequently, the SDVGs exhibit higher patency (100%) and more stable morphology following porcine carotid artery transplantation for 9 months and rabbit carotid artery transplantation for 3 months. Therefore, such a bioinspired, antithrombotic, and visualizable SDVG presents a promising design approach for long-term patency products and great potential of helping patients with cardiovascular diseases.

Fine-Tuning MOFs with Amino Group for One-Step Ethylene Purification from the C2 Hydrocarbon Mixture.

Due to the similar kinetic diameters of C2H2, C2H4, and C2H6, one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture by adsorption separation is still a challenge. Based on a C2H6-trapping platform and crystal engineering strategy, the N atom and amino group were introduced into NTUniv-58 and NTUniv-59, respectively. Gas adsorption testing of NTUniv-58 showed that both the C2H2 and C2H4 uptake capacities and the C2H2/C2H4 separation ability were boosted compared with the original platform. However, the C2H4 uptake value exceeds the C2H6 adsorption data. For NTUniv-59, the C2H2 uptake at low pressure increased and the C2H4 uptake decreased; thus, the C2H2/C2H4 selectivity was enhanced and the one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture was realized, which was supported by the enthalpy of adsorption (Qst) and breakthrough testing. Grand canonical monte carlo (GCMC) simulation indicated that the preference for C2H2 over C2H4 originates from multiple hydrogen-bonding interactions between amino groups and C2H2 molecules.

Discovery of novel benzamide derivatives bearing benzamidophenyl and phenylacetamidophenyl scaffolds as potential antitumor agents via targeting PARP-1.

Poly(ADP-ribose) polymerase-1 (PARP-1) plays a crucial role in DNA damage repair and has been identified as a promising therapeutic target in cancer therapy. As a continuation of our efforts on the development of novel PARP-1 inhibitors with potent anticancer activity, a series of benzamide derivatives containing the benzamidophenyl and phenylacetamidophenyl scaffolds were designed and synthesized based on the structure optimization of our previously reported compound IX. All target compounds were screened for their in vitro antiproliferative activities against human colorectal cancer cells (HCT116, DLD-1 and SW480) and human normal colonic epithelial cells (NCM460). Among them, compound 13f exhibited the most potent anticancer activity against HCT116cells and DLD-1cells with IC50=0.30μM and 2.83μM, respectively. Moreover, 13f displayed significant selectivity in inhibiting HCT116 cancer cells over the normal NCM460cells. Furthermore, 13f exhibited excellent PARP-1 inhibitory effect with IC50=0.25nM. Besides, 13f was found to effectively inhibit colony formation and migration of HCT116cells. Studies on the mechanisms revealed that 13f could arrest cell cycle at G2/M phase, accumulate DNA double-strand breaks, reduce mitochondrial membrane potential and ultimately induce apoptosis in HCT116cells. In addition, molecular docking study indicated that 13f could combine firmly with the catalytic pocket of PARP-1 through multiple hydrogen bond interactions. Collectively, these findings demonstrated that 13f could serve as a promising anticancer candidate and deserves further investigation.