Chemical Science
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2025
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IF 7.4
Yuping Chen,Guoqing Bian,Zhikun Wu,Qing Tang
Ligand exchange is an important strategy to functionalize metal nanoclusters (NCs) for enhanced properties. Thiolates and alkynyls have been widely used for NC protection, however, the possibility for alkynyl-for-thiolate exchange as well as the kinetics for the ligand exchange process have remained largely unexplored. Herein, we reported the first kinetic investigation into the alkynyl-for-thiolate exchange through the reaction of thiolated Au25(SR)18 with the incoming alkynyl ligands. Interestingly, our simulations revealed the electronic and steric effect of alkynyl ligands, and the precursor cluster’s charge state collectively govern the exchange efficiency and regioselectivity. Notably, the alkynyl-for-thiolate exchange is highly facile when reacting with the nucleophilic lithium or gold(I)−alkynyl complex (Au(C≡CR) or Li(C≡CR)), but fails when using HC≡CR as the exchange ligand. The Au(C≡CPh) complex exhibits charge-state-dependent exchange at the S1 or S2 position, whereas the sterically bulky Au(C≡CtBu) complex decelerates the exchange kinetics and universally targets the S1 position as the exchange product. By contrast, the lithium-alkynyl complex (Li(C≡CPh) or Li(C≡CtBu)) preferentially leads to the S1' exchange isomer, driven by the ionic Li−C bonding that enhances the C≡C π*-electron density and alkynyl nucleophilicity. Our predictions are further validated by the ligand exchange experiments between phenyl ethanethiol (PET) protected [Au25(PET)18]− and Au(C≡CtBu). The electrospray ionization mass spectra (ESI-MS) unambiguously confirms the successful substitution of about 4, 5 and 6 PET ligands by the −C≡CtBu ligand, and the absorption spectrum is drastically changed upon the alkynyl exchange. This work establishes important atomic-level understanding of the alkynyl-for-thiolate exchange mechanism, offering a convenient strategy of realizing alkynyl and thiolate co-protected gold clusters under mild conditions.
研究领域:
纳米材料
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物理化学
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团簇科学
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材料化学
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表面化学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Caiyun Han,Jing Xie,Xize Min
Due to the non-degradable of heavy metal, adsorption has been extensively applied to abatement it. Most studies were focused on uptake metal ions via electrostatic attraction and ion exchange, and load molecule H 3 AsO 4 from strongly acidic wastewater was still challenging. To solve the problem, bimetallic La–Zr MOFs was facilely fabricated in this work, and the fcu topology structure of La-Zr MOFs was remained well under the investigate crystallization time and crystallization temperature. However, the crystallinity of the obtained La-Zr MOFs was influenced by the synthesized factors. The obtained La–Zr MOFs was employed as adsorbent to removal Cr(VI) and As(V), and the performance was evaluated by the batch experiment. The result indicated that the adsorption performance of Cr(VI) and As(V) was positively correlated with the crystallinity , and the optimal sample was 1LaUN 12 . From the XPS characterization, it was found that H 3 AsO 4 was successfully uptake over 1LaUN 12 surface, and the maximum monolayer adsorption capacity was 83.40 mgH 3 AsO 4 /g via ligand exchange and coordination reactions with La−OH and Zr−OH. In addition, the sample 1LaUN 12 also exhibited the excellent Cr(VI) load performance, and the maximum monolayer adsorption capacity of Cr(VI) was 222.5 mg/g. Above 40% Cr(VI) was reduced to Cr(III) by amino groups, and immobilized over the surface of 1LaUN 12 . Eventually, 1LaUN 12 displayed a good structural stability in the acidic medium, which was in favor of removing Cr(VI) and As(V) efficiently from strongly acidic solutions.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Physical Chemistry C
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2020
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IF 4.189
Meng Liu,Ying-Ying Wang,Yi Liu,Feng-Lei Jiang
Ligand exchange is a critical step for tuning the properties of quantum dots (QDs), as well as functionalization for wide applications. Previous studies have categorized X-, L-, and Z-types of ligands and classified the ligand exchange process accordingly. Many works have investigated the influences of ligand exchange on the optical properties of QDs. To date, however, the thermodynamic implications of ligand exchange are not well understood, and the mechanisms of distinct effects of the ligands of the same type are unclear. To address these issues, ligand exchange reactions of the oleate-capped CdSe QDs with alkylamines of different carbon chain length, namely, n-butylamine (C4Am), n-octylamine (C8Am), n-dodecylamine (C12Am), were investigated using 1H nuclear magnetic resonance (1H NMR) spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. 1H NMR studies showed that the equilibrium constants (Keq) for the desorption of the Z-type ligand (cadmium oleate) from the surface of CdSe QDs, as promoted by the L-type ligands (alkylamines), were in the order of C4Am > C8Am > C12Am, presumably highlighting the small steric barrier of ligands with short carbon chain. In addition, the ligand exchange was studied by fluorescence titration at varied temperatures from a perspective of ligand adsorption following the desorption of cadmium oleate. The binding constants were of magnitude 103 M–1. A “two-step ligand exchange” (TSLE) model was developed to describe the ligand desorption–adsorption process with thermodynamic perspectives. The increased length of the carbon chain brought not only increasing steric barrier but also increasing van der Waals interactions, exhibiting a double-edged sword effect in ligand exchange. The ligand exchange with C8Am contributed the most negative value of ΔH and ΔS since the van der Waals interactions between C8Am and neighboring ligands were stronger than that for C4Am, whereas its steric barrier was weaker than that of C12Am. These demonstrated the importance of ligand–ligand interactions, relatively less documented in the previous studies, besides the predominance of the nanocrystal–ligand interactions. UV–vis absorption spectroscopic and fluorescence lifetime studies further showed that the ligand exchange with all three alkylamines affected optical properties of CdSe QDs to some extent. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that the ligand exchange process basically did not affect the crystal structure and core size of the CdSe QDs. Our work had proposed a conceivable mechanism for ligand exchange, elucidated the thermodynamic implications, and provided a reasonable guidance for selection of suitable ligands.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2023
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IF 3.3
Xinjia Zhang,Yanchao Li,Jianguo Mi,Xiuqing Kang,Junsu Jin
Atmospheric water adsorption at low humidity is considered to be a major challenge in solving global water problems. As a routine water adsorbent, the University of Oslo-66 (UiO-66) powder has been restricted by its limited low-pressure water absorption capacity, the need for powder molding, and insufficient adsorption rates. To overcome these problems, this work prepares E-UiO-66@PAA spherical composites by crystallizing UiO-66 on the surface of macroporous polyacrylate, i.e. PAA porous spheres, through in situ confined growth and ligand exchange strategies. The average size of the crystals has been reduced by 4 times vtihe nanoscale roughness of the polymer substrate surface and the interfacial enrichment of the precursor solution to lower the energy barriers of heterogeneous nucleation. In addition, the coordination of the hybrid ligand with Zr 4+ creates a unique cavity structure and gives rise to novel micropores as a result of ligand defects, which can be fitted into the lattice as binding sites for water. In the water vapor adsorption test at 298 K, E-UiO-66@PAA was able to operate at 4.9 times the capacity at low pressure (0.1 < P/P 0 < 0.2) and advanced the adsorption saturation time by 30.7% of the pristine UiO-66. Especially, the relative pressure of the sudden change in water vapor uptake was reduced from 0.3 to 0.1, which could greatly save the energy required for vapor regeneration and reduce its operating cost. This study provides an effective method to improve the adsorption capacity, mass transfer rate, and workability of composites by designing a nanoporous structure and confined growth nuclei as adsorption sites.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Applied Sciences-Basel
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2025
·Vol. 15
·期 14
·7829
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IF 2.5
Mengfei Ma,Yingpeng Gu,Ruijie Wang,Yue Sun
The deep defluorination of water remains a significant environmental challenge. In this work, aluminum was loaded onto the bifunctional resin S957 containing a phosphoric-sulfonic acid difunctional group for efficient fluoride removal. Al-S957 demonstrated excellent fluoride removal performance across a broad pH range. When anions and organics coexisted, Al-S957 exhibited significantly better fluoride adsorption performance compared to aluminum-loaded monofunctional resins. The adsorption followed an endothermic chemisorption process on a monolayer surface. FTIR and XPS analyses further revealed that fluoride removal relied on a ligand exchange mechanism. Column adsorption conducted over five cycles highlighted the strong practical potential of Al-S957. The results suggested that Al-S957 exhibits significant potential for practical applications.
研究领域:
环境科学
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水处理技术
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吸附材料
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环境功能材料
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2021
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IF 9.229
Yi-Rou Jin,Yi Liu,Feng-Lei Jiang
N,N,N′,N′-Tetramethylethylenediamine (TMEDA) and ethylenediamine (EDA) were investigated in-depth in the ligand exchanges for water-soluble CdSe quantum dots (QDs). TMEDA could assist the phase transfer of QDs from apolar solvents to the aqueous solutions as stabilized by mercaptopropionic acid (MPA). We successfully maintained the stability of a series of MPA-capped QDs of different ligand densities for NMR characterizations in aqueous solutions. The proton NMR spectroscopies of MPA of the binding state were used to analyze the ligand densities on the surface of QDs, which were not explored in the past. The binding thermodynamics of the surface ligands of QDs, as analyzed using the Hill equation, demonstrated a positive promoting effect and possible interactions between ligands. EDA in the purification process underwent a spontaneous adsorption with two-stage thermodynamic behaviors as characterized by isothermal titration calorimetry. Due to the positive role of the already adsorbed ligands, excess EDA would further attach to the surface of QDs in the form of non-bonded physisorption, greatly improving the quantum yield (QY) of QDs, and the ligand of this part would almost not change the stability of QDs. We proposed a strategy for the preparation of aqueous QDs with a high QY, followed by fluorescence quenching-enhancement cycles caused by purification-adsorption operations. The strategy made it possible for the preparation of functional QDs with small molecules after purification operations. Kinetics of the sorption of ligands on the surface of QDs were determined by fluorescence spectroscopy. Modified pseudo-second-order kinetics after consideration of the ligand–ligand interaction effect could well analyze the kinetic data. This kinetic model had advantages over the previous ligand exchange model in terms of accuracy, reproducibility, and physical significance. Finally, we used the above strategy for the design of fluorescent QDs for bioimaging of lysosomes, mitochondria, and cancer cells. This work can simplify the preparation of multifunctional fluorescent QDs and avoid complicated ligand design.
研究领域:
材料科学
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生物医学工程
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化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2019
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IF 8.456
Wen Zhang,An Bu,Qingyuan Ji,Luofu Min,Song Zhao,Yuxin Wang,Jing Chen
We report a class of pKa-directed, precise incorporation of phosphonate ligands into a zirconium-based metal–organic framework (Zr-MOF), MOF-808, via ligand exchange. By replacing of formate ligands with methylphosphonic acid (MPA), ethanephosphonic acid (EPA), and vinylphosphonic acid (VPA), whose pKa values are slightly higher than that of the benzenetricarboxylic acid (BTC) linker in MOF-808, daughter MOFs can be synthesized without controlling the stoichiometric amounts of added MPA. The methylphosphonate MOFs (808-MPAs) demonstrate high porosities, with only small changes in the pore diameter and specific surface area when compared with the parent MOF-808. PXRD patterns and structure refinements indicate the expansion of the lattice for all MOFs after decorating with methylphosphonate ligands. The XPS spectra reveal a charge redistribution of the Zr6 node after ligand exchange. FTIR and 31P MAS NMR spectra, combined with DFT calculation, suggest that the methylphosphonate ligand is connected to the Zr6 node as CH3P(O)(OZr)(OH) species with an accessible acidic P–OH group. Besides, 808-MPAs demonstrate excellent chemical stability in concentrated HCl, concentrated HNO3, hot water, and 0.2 mol/L trifluoroacetic acid solutions. Impressively, 808-MPAs show ultrafast adsorption performance for uranyl ions using the ion-exchange property of P–OH sites in their cavity environment, with an equilibrium time of 10 min, much quicker than the previous adsorbents. The present study demonstrates a series of important proof-of-concept examples of the pKa-directed Zr-MOFs with tunable phosphonate-terminated ligands, which can extend to other phosphonate-functionalized Zr-based framework platforms in the near future.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Guanlei Gao,Si-Yu Xu,Xinghui Qi,Jie-Ru Yang,Peiqi Lin,Jin Chen,Xiao-Ying Huang,Ke-Zhao Du
The strategy of organic ligand exchange is proposed to tune the optical properties of organic–inorganic hybrid cuprous halides. In this work, the chiral ligand (S)-(−)-2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl ((S)-Tol-BINAP) and achiral triphenylphosphine (PPh3) are introduced into cuprous halides CuX-PPh3-[(S)-Tol-BINAP] (X = Cl, Br, I) through organic ligand exchange. As a result, the mixed organic ligands can enhance second harmonic generation (SHG) and aggregation-induced emission (AIE) optical properties. Moreover, the title compounds exhibit progressively enlarged SHG effects along with heavier halogen substitution due to their stronger polarizability. In the meantime, the reduced π–π stacking interaction of the organic ligand will improve their photoluminescence quantum yield. The experimental results combined with the theoretical calculation clarify the structure–property relationship well. Furthermore, the title compounds have been developed for the application of latent fingerprint detection.
研究领域:
材料科学
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化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Tian Jia,Yuanze Hong,Zhipeng Wei,Baoxia Mu,Xuechao Yu
Near-infrared photoelectric detectors are widely used in the military and national economy, such as aerospace, optical communication, and near-infrared imaging. Graphene/quantum dots (QDs) hybrid photodetectors possessing high responsivity and broadband spectral range have been prodigiously studied due to the combination of high mobility of graphene, broad spectral response, and high light absorption of QDs. However, the long-chain ligands that modify the outer surface of the QDs stem the transfer of charge carriers, thus hindering the performance of the hybrid photodetectors. Here, we demonstrate colossal response in Graphene/QDs detectors via a two-step ligand exchange method to exchange the inceptive long chains with specifically selected molecules. Prior to the solid-state ligand exchange, QDs were pretreated with methylammonium iodide (MAI) in solution as the first ligand exchange and 1,2-ethanedithiol (EDT) was redeposited after the tetrabutylammonium iodide (TBAI) ligand exchange in the second step to ensure complete passivation of surface defects. After the two-step ligand exchange process, the device performances have been significantly improved. The responsivity and detectivity of the device are 6.7 × 103 A·W–1and 1.86 × 109 Jones, respectively, which are increased by 2 orders of magnitude, heralding the development of high-performance near-infrared photodetection and imaging systems in integrated photonics applications.
研究领域:
材料科学
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光电子学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2019
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IF 6.393
Shuqin Yang,Zhilong Song,Naibo Gao,Zhixiang Hu,Licheng Zhou,Jingyao Liu,Baohui Zhang,Guangzu Zhang,Shenglin Jiang,Hua-Yao Li,Huan Liu
Indium oxide (In 2 O 3 ) nanomaterials have been investigated extensively as promising candidates for gas sensor applications. Here, we fabricate near room temperature operable H 2 S-sensitive gas sensors based on In 2 O 3 colloidal quantum dots (CQDs). Room-temperature film deposition of In 2 O 3 CQDs followed by surface ligand exchange treatment through Cu inorganic salts was employed to construct the sensor devices. Combined with a moderate annealing treatment, the long-chain ligands surrounding the quantum dot surfaces were completely removed to enhance gas adsorption and carrier transport, simultaneously resulting in the formation of CuO that may act as a catalytic promoter or form p-n heterojunction for selective H 2 S detection. The sensors exhibited high response up to 90 toward 5 ppm of H 2 S with response/recovery time of 72 s/200 s respectively, suggestive of a performance improvement compared to the In 2 O 3 -based H 2 S sensors reported in existing literature. The power law analysis indicated that the main oxygen species adsorbed on the surfaces were O 2 − and O − with the proportion of approximate 1:1 at near room temperature. The gas-sensing mechanism was attributed to the decisive role of surface states in determining the electrical conduction of quantum dot gas sensors.
研究领域:
材料科学
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传感器技术
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纳米科技
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Lingrui Zhang,Jinling Xie,Xuan Luo,Xiaobo Gong,Meng Zhu
Oil and organic solvent spills have caused serious environmental issues. To address these issues, several novel materials have been developed for the efficient separation of oil/organic solvents from water. In this study, ZIF-8 was loaded onto a melamine foam (MF) skeleton a simple in situ growth method. ZIF-8/MF was modified via a shell-ligand-exchange reaction (SLER) to improve its hydrophobicity. The prepared D-ZIF-8/MF exhibited strong hydrophobicity, with a WCA of 145.1° and an OCA of 0°. D-ZIF-8/MF can absorb up to 68–165 times its weight in oil/organic solvents. D-ZIF-8/MF also exhibited excellent stability, corrosion resistance, recovery, and recyclability. Furthermore, D-ZIF-8/MF has a high oil-water separation efficiency for absorbing organic solvents through a continuous oil-water separation device. This study provides a novel strategy for the preparation of strong hydrophobic foams via surface modification and SLER for oil-water separation. It has immense potential for the scale-up practical treatment of oily wastewater.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yue Yin,Gaoyang Xu,Yuxing Xu,Mengyan Guo,Yihua Xiao,Tao Ma,Changqing Liu
The ubiquitous presence of inorganic and organic phosphorus in wastewater and natural water bodies has deteriorated the water environment qualities and exerted significant influences on ecosystems. In this study, an effective polypyrrole modified red mud adsorbent (PRM) was optimized for the adsorptive removal of inorganic and organic phosphorus from aqueous solutions. The addition of ferric chloride and pyrrole was optimized for complete oxidation and modification of polypyrrole onto red mud. Kinetic studies illustrated that the adsorption progress was accomplished by physical and chemical adsorption. The experimental data of the optimized PRM were described well by Langmuir isotherm, and the equilibrium adsorption capacity was 32.9 and 54.7 mg/g for inorganic and organic phosphorus, respectively. The PRM showed commendable adsorption performance despite the pH conditions ranging from 3 to 11. From the effect of ion strength and X-ray photoelectron spectroscopy (XPS) tests, we found that ligand exchange is the main mechanism of orthophosphate adsorption onto PRM, while electrostatic attraction played an important role in organic phosphorus adsorption. The adsorption performance from column studies showed that the velocity of flow influenced the breakthrough time of the column but the initial concentration had minor impacts. This study would extend the potential application of polypyrrole modified red mud, acting as an efficient adsorbent for inorganic and organic phosphorus adsorption in water treatment .
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）