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Chemical Research in Chinese Universities
Journal Prestige (SJR): 0.261  Citation Impact (citeScore): 1 Number of Followers: 4  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1005-9040 - ISSN (Online) 2210-3171 Published by Springer-Verlag  [2467 journals]
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- Organic Functional Free Radicals
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PubDate: 2023-03-14
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- Stable Radical TEMPO Terminated Perylene Bisimide(PBI) Based Small
Molecule as Cathode Interlayer for Efficient Organic Solar Cells-
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Abstract: Abstract By combining stable radical tetramethylpiperidine nitrogen oxide(TEMPO) as end groups and perylene bisimide(PBI) as the core, a small molecular cathode interlayer(CIL) (PBI-TEMPO) was synthesized. Detailed physical-chemical characterizations indicate that PBI-TEMPO can form smooth film, owns low unoccupied molecular orbital(LUMO) level of −3.67 eV and can reduce the work function of silver electrode. When using PBI-TEMPO as CIL in non-fullerene organic solar cells(OSCs), the PM6:BTP-4Cl based OSCs delivered high power conversion efficiencies(PCEs) up to 17.37%, higher than those using commercial PDINO CIL with PCEs of 16.95%. Further device characterizations indicate that PBI-TEMPO can facilitate more efficient exciton dissociation and reduce charge recombination, resulting in enhanced current density and fill factor. Moreover, PBI-TEMPO displays higher thermal stability than PDINO in solution. When PBI-TEMPO and PDINO solution were heated at 150 °C for 2 h and then were used as CIL in solar cells, PBI-TEMPO-based OSCs provided a PCE of 15%, while PDINO-based OSCs only showed a PCE of 10%. These results demonstrate that incorporating TEMPO into conjugated materials is a useful strategy to create new organic semiconductors for application in OSCs.
PubDate: 2023-03-13
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- Recent Advances of Stable Phenoxyl Diradicals
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Abstract: Abstract Organic radicals with unpaired electrons have shown great semiconducting properties with potential applications in the field of organic photodetectors, organic light-emitting diodes and organic spintronics. A major problem for limiting radicals from laboratory research to practical applications is the relatively low chemical and physical stabilities. Therefore, the right selection of radical core is the key to meaningful scientific research. Phenoxyl radical is one of the few stable radicals with spin distribution properties. Moreover, phenoxyl diradicals provide extract stability due to multiple resonance structures. Due to the long-distance spin distribution, which makes phenoxyl diradicals show interesting electronic and magnetic properties. In this review, we summarize the progress of phenoxyl diradicals in recent years in terms of syntheses, properties and future perspective.
PubDate: 2023-03-13
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- Electronic Characteristics of Perylene Diimide Anion Radical and Dianion
Films by Quantitative Doping-
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Abstract: Abstract Due to their unique physicochemical properties, the anion radical and dianion of perylene diimide derivatives(PDIs) recently attracted significant attention for organic semiconductors. However, the impact of packing structure and the radical content for carrier transport in the solid state still need to be determined. Bringing the electron-withdrawing groups is an effective strategy for enabling π−π stacking distance. Here, bay-tetrachloro-substituted PDI(B-4Cl-PDI) anion radical and dianion films were fabricated quantitatively doped with N2H4·H2O. The radical contents were quantitatively calculated by absorption spectra in different doping ratios. The X-ray powder diffraction patterns showed that the anion radical presented a crystalline structure, and dianion aggregates exhibited an amorphous structure. With precise manipulation of the radical content, the anion radical aggregates and dianion aggregates showed the maximum electrical conductivity value of 0.024 and 0.0018 S/cm, respectively. The experiment results show that doping level and aggregate structure play a crucial role in electronic transport properties.
PubDate: 2023-03-08
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- Spatial Correlation in Typical Binary Polycondensation Systems: An
Essential Extension of the Kirkwood-Buff Theory-
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Abstract: Abstract We present the isothermal susceptibility(χT) for the typical binary polycondensation system of Af-Bg type, and relate χT to the weight-average degree of polymerization in terms of the Kirkwood-Buff(KB) theory. The investigation is based on a new expression of χT for mixtures, which is still expressed by the KB integrals(KBIs) but endowed with an explicit physical interpretation. For polymerization systems, it is proposed that the KBIs can be further decomposed according to whether there exists a bond between particles when conversions (extents of reaction) of functional groups are incorporated into the KBIs. In this way, χT is directly decomposed into its relevant components as well. This is especially useful to reveal the relationship between local structures and average properties of various polymerization systems. As a consequence, the effect of polymerization on χT is greatly simplified in comparison with the free energy route. Therefore, we have provided a very simple method to carry out some thermodynamic properties of polymerization systems.
PubDate: 2023-03-07
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- Chalcogen Effect of Atom Substitution on the Properties of
Tris(2,4,6-trichlorophenyl)methyl(TTM) Radical-
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Abstract: Abstract Luminescent open-shell organic radicals have recently been regarded as one of the most potential materials in organic light-emitting diodes(OLEDs). Herein, we have synthesized two new organic radicals, namely tris{4-[4-(tert-butyl)phenoxy]-2,6-dichlorophenyl}methane radical(TTM-O) and tris(4-{[4-(tert-butyl)-phenyl]thio}-2,6-dichlorophenyl)methane radical(TTM-S), by the substitution of chalcogen atom elements at the para position of conventional tris(2,4,6-trichlorophenyl)methyl(TTM) radical moiety. Interestingly, both TTM-O and TTM-S exhibited significantly enhanced photostability compared with the unsubstituted TTM radical parent. Moreover, the chalcogen atom also had a crucial impact on the photoluminescence quantum yield(PLQY) of the radicals, i.e., the PLQY of TTM-S was greatly enhanced compared to TTM radical while TTM-O was nearly non-emissive. Particularly, TTM-S showed intense PLQY of 37.54% and 185-fold longer photostability than that in cyclohexane solution of TTM.
PubDate: 2023-03-07
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- Progress of Indeno-type Organic Diradicaloids
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Abstract: Abstract Organic diradicaloids have unusual open-shell nature and properties and are promising materials for organic electronics, spintronics, energy storage and nonlinear optics. In this review, we focus on indeno-type organic diradicaloids and summarize their molecular design and synthesis, as well as topological structures, open-shell characters and diradical properties. The molecular systems are classified into indenofluorenes and diindenoacenes, indeno-based molecules with one-dimensional, two-dimensional and unique topological structures, and heterocyclic indeno-based molecules. By constructing these various topological π-skeletons with tunable conjugation modes and variation of atomic composition, their key open-shell parameters, such as diradical characters and singlet-triplet energy gaps, along with the optical, electronic and magnetic properties, as well as stabilities are efficiently modulated. More attention may be paid to accurate computational analysis, rational design and synthesis, and novel functions of indeno-type diradicaloids, which will promote the development of radical chemistry and materials.
PubDate: 2023-03-07
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- Effects of Electron Donating Ability of Substituents and Molecular
Conjugation on the Electronic Structures of Organic Radicals-
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Abstract: Abstract The geometries and electronic structures of a series of electron donor-acceptor radical molecules have been studied theoretically. The computational results show that the introduction of substituents with strong electron donating ability into tri-(2,4,6-trichlorophenyl) methyl(TTM) radicals enables the radical molecules to form the non-Aufbau electronic structure. The difficulty of forming the non-Aufbau electronic structure decreases with the enhancement of the electron donating ability of the substituent, but the expansion of the molecular conjugated system is not conducive to the formation. The hybridization of different fragments in molecular orbitals results in the disproportionation of orbital energy level and forms a staggered energy level structure. The electronic structure of radical molecules can be adjusted by substituents and molecular skeleton profoundly, which is a very effective means for molecular design.
PubDate: 2023-03-06
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- Ball-milling Synthesis of Single-atom Cu Anchored on N-Doped Carbon for
Mimicking Peroxidase-
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Abstract: Abstract Nanozymes have shown great potential for life sciences owing to their distinct advantages, such as low cost and high stability, compared with natural enzymes. Despite significant progress, state-of-art nanozymes commonly suffer from relatively low specific activities. Herein, we propose a promising to address this issue by creating single-atom nanozymes. A ball-milling-assisted strategy has been developed to induce the transformation of Cu species from bulk to single atoms. The highly-simplified steps allow a large-scale synthesis, that over 4.2 g of single-atom Cu−N doped carbon nanozymes can be achieved in one pot. It exhibits a remarkably improved peroxidase-like activity and stability compared with N doped C anchored Cu nanoparticles. Further experimental firmly reveals the crucial role of the single-atom Cu site that can generate more active ·OH species for boosting the catalytic process.
PubDate: 2023-03-02
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- Stable Near-infrared-emitting Radical Nanoparticles for Fluorescence
Imaging-
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Abstract: Abstract Stable neutral luminescent radicals with unpaired electrons exhibit unique spin-allowed doublet-doublet transitions, which has attracted significant attention. Although they are pure organic molecules without metal ions thus thought to have low biological toxicity, the application of luminescent radicals to bioimaging has rarely been reported. Here, a stable radical with efficient near-infrared(NIR) emission and good photostability was designed and synthesized. After being wrapped into nanoparticles, it was applied to cell fluorescence imaging. The cytotoxicity experiments suggested that the nanoparticles have remarkable biocompatibility and excellent stability. An NIR fluorescent signal was successfully observed in the cytoplasm of HCT116 cells. The experimental results gave the first example of NIR emitting radical nanoparticles for cell fluorescence imaging and proved the feasibility of the application of luminescent radicals to fluorescence imaging.
PubDate: 2023-02-27
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- Solvent-dependence of KI Mediated Electrosynthesis of
Imidazo[1,2-a]pyridines-
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Abstract: Abstract Iodized salts are widely used as mediators to promote C-H functionalization. Solvents and additives have been described as significant roles in these reactions. However, the further electrochemical investigations have rarely been reported. Herein, a KI mediated electrochemical annulation between acetophenones and 2-amniopyridines was developed. We revealed the effect of acids and solvents by cyclic voltammetry(CV), differential pulse voltammetry(DPV), and square wave voltammetry(SWV). The oxidation of 2-aminopyridine is inhibited at the potential window with the addition of strong acids, and the lowest oxidation potential difference of KI was obtained by utilizing EtOH as solvent. The experimental studies also show that the mixture solvent of EtOH/DMSO(9/1, volume ratio) facilitates the electrochemical cyclization due to the solubility improvement of KI. CF3SO3H has been screened as the optimal acid. A range of Imidazo[1,2-a]-pyridines have been synthesized in yields of 42% to 96%. Electrochemical investigations present that the KI mediated electrochemical reaction is probably solvent-dependence.
PubDate: 2023-02-18
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- Special Issue of Bio-inspired Material Chemistry
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PubDate: 2023-02-01
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- Bioinspired Strategies for Stretchable Conductors
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Abstract: Abstract Stretchable conductors are indispensable components of stretchable electronic devices, such as stretchable sensors, transistors, light-emitting diode arrays, solar cells, and so on. However, most of the conductive materials are stiff with very low stretchability. Nature has evolved various strategies to realize stretchability, which give a lot of inspirations to the design and fabrication of stretchable conductors. We herein summarized the nature’s strategies to realize stretchability and revealed the underlying mechanisms. After that, the applications of these strategies in fabricating stretchable conductors are exemplified and the effects of some important parameters on the performances are discussed. Then, possible applications of these stretchable conductors are summarized. Finally, critical issues in the stretchable conductors are discussed and several prospective exploration directions are provided.
PubDate: 2023-02-01
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- Chemically Amplified Resist Based on Dendritic Molecular Glass for
Electron Beam Lithography-
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Abstract: Abstract A novel dendritic molecular glass(MG) containing adamantane core(AD-15) was synthesized and characterized. It exhibits good solubility in common organic solvents and a stable amorphous state at room temperature, which contributes to forming films with different thicknesses by spin-coating. The thermal analysis of AD-15 indicates that no apparent glass transition temperature(Tg) is observed before the thermal decomposition temperature(Td=160 °C). The good thermal resistance suggests that it can satisfy the lithographic process and is a candidate for photoresist materials. The patterning properties of AD-15 resist were evaluated by electron beam lithography(EBL). By optimizing the lithographic process parameters, AD-15 resist can achieve 40 nm half-pitch patterns with a line-edge roughness of 4.0 nm. The contrast and sensitivity of AD-15 resist were 1.9 and 67 µC/cm2, respectively. Compared with the commercial PMMA(950k) electron beam resist, the sensitivity of AD-15 resist increases by 6 times. This study provides a new example of molecular glass resist with high resolution and sensitivity for EBL.
PubDate: 2023-02-01
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- Recent Progress of Bio-inspired Camouflage Materials: From Visible to
Infrared Range-
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Abstract: Abstract The adaptability of biological organisms to the environment is reflected in many aspects, especially in their camouflage of appearance. Inspired by biological camouflage strategies, a number of adaptive camouflage materials and devices have been developed to protect soldiers, vehicles, or equipment in the military. Today, the need for adaptive camouflage extends into people’s lives, whose privacy and information security need to be protected in the era of big data. Herein, a review is provided on the recent advancements of adaptive camouflage from the perspective of biological organisms and bio-inspired materials. Firstly, according to different biological mechanisms, we review the typical organisms that use pigmentary color, structural color, and morphological variation for adaptive camouflage, as well as those combine these strategies. Then, we provide an up-to-date review on recent developments in bio-inspired adaptive camouflage materials and devices with an emphasis on visible, infrared, and multispectral camouflage. At last, this review concludes the challenges and prospects for the future development of adaptive camouflage materials. It is noteworthy that there is never the best camouflage. To counter advanced detection techniques, it is necessary to unremittingly develop new materials and technologies to meet the increasing need for adaptive camouflage.
PubDate: 2023-02-01
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- Enzymes in Nanomedicine for Anti-tumor Therapy
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Abstract: Abstract Natural enzymes are biological macromolecules catalyzing reactions in living organisms and regulating biological processes. Targeted delivery of enzymes into tumor tissues for anti-tumor therapy through nanotechnology has attracted emerging interest in recent years. In this paper, we systematically summarize the latest research progress on enzymes that used for anti-tumor therapy in nanomedicine with different action mechanisms, including anti-tumor principles, delivery modes, response modes, and synergistic therapeutic design of these enzymes. Finally, we discuss the challenges and future prospects of enzymes for anti-tumor nanomedicine.
PubDate: 2023-02-01
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- Functional Peptides from One-bead One-compound High-throughput Screening
Technique-
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Abstract: Abstract Combinatorial chemistry provides a cost-effective method for the rapid discovery of new functional peptides. One-bead one-compound(OBOC) high-throughput screening technique offers a lot of structurally diverse peptides to be rapidly synthesized and screened for binding to a target of interest. The OBOC peptide library screening involves three main steps: library construction, positive beads separation, and peptide sequencing. This review mainly summarizes some special technique tips during functional peptide screening and potential future directions of the OBOC high-throughput screening technique.
PubDate: 2023-01-18
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- Construction and Application of DNAzyme-based Nanodevices
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Abstract: Abstract The development of stimuli-responsive nanodevices with high efficiency and specificity is very important in biosensing, drug delivery, and so on. DNAzymes are a class of DNA molecules with the specific catalytic activity. Owing to their unique catalytic activity and easy design and synthesis, the construction and application of DNAzymes-based nanodevices have attracted much attention in recent years. In this review, the classification and properties of DNAzyme are first introduced. The construction of several common kinds of DNAzyme-based nanodevices, such as DNA motors, signal amplifiers, and logic gates, is then systematically summarized. We also introduce the application of DNAzyme-based nanodevices in sensing and therapeutic fields. In addition, current limitations and future directions are discussed.
PubDate: 2023-01-16
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- Self-assembled Supramolecular Artificial Transmembrane Ion Channels:
Recent Progress and Application-
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Abstract: Abstract Natural protein channels have evolved with fantastic spatial structures, which play pivotal physiological functions in all living systems. Learning from nature, chemical scientists have developed a myriad of artificial transmembrane ion channels by using various chemical strategies, among which the non-covalent supramolecular ion channels exhibit remarkable advantages over other forms(e.g., single-molecule ion channel), which exhibited facile preparation methods, easier structural modification and functionalization. In this review, we have systematically summarized the recent progress of supramolecular self-assembled artificial transmembrane ion channels, which were classified by different self-assembly mechanisms, such as hydrogen bonds, π-π interactions, etc. Detailed preparation process and self-assembly strategies of the supramolecular ion channels have been described. Moreover, potential biomedical applications of the supramolecular ion channels have also been carefully discussed in this review. Finally, future opportunities and challenges facing this field were also elaborately discussed. It is anticipated that this review could provide a panoramic sketch and future directions towards the construction of novel artificial ion channels with novel functions and biomedical applications.
PubDate: 2023-01-14
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- Superhydrophobicity-improved Ethanol-Water Separation
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Abstract: Abstract Efficient separation of biofuels from fermentation broths vis pervaporation plays an important role in addressing the global challenges, such as developing renewable energy. Great efforts have been continuously devoted in the past decades to developing high-performance pervaporation membranes. A recent report published in Science by Zhao et al. showed that a superhydrophobic surface could contribute significantly to improving the pervaporation separation of ethanol-water mixture, which will generate broad interest for the new design of separation membranes.
PubDate: 2023-01-06
DOI: 10.1007/s40242-023-2320-1
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