HELVETICA CHIMICA ACTA
·
2017
·Vol. 100
·期 12
·e1700162
·
IF 1.071
Jun Wang,Rui Gao,Na Zhang,Xiangkun Tan,Libo Wang,Lili Ma,Weiguang Shi
Three dendritic PNP ligands with ethylenediamine, 1,4-butanediamine, 1,6-diaminohexane as bridged groups are synthesized in good yields, respectively. Three dendritic PNP chromium complexes ( C1 – C3 ) are prepared with the ligands and chromium(III) chloride tetrahydrofuran complex (CrCl 3 (THF) 3 ) as materials. The dendritic PNP ligands and the synthetic chromium complexes are fully characterized by spectroscopic and analytical methods. All chromium complexes activated with methylaluminoxane (MAO) exhibited moderate activities on ethylene oligomerization (7.90 × 10 4 – 2.15 × 10 5 g (mol Cr h) −1 ] and had better selectivity for C 6 and C 8 oligomer, reaching up to 81%. The chromium complex ( C1 ) activated with diethylaluminium chloride (Et 2 AlCl) has higher catalytic activity than the chromium complex C1 activated with MAO, although the chromium complex ( C1 ) activated with Et 2 AlCl had lower selectivity for C 6 and C 8 oligomer. The effects of solvent and reaction parameters on ethylene oligomerization are also studied using the chromium complex C1 as pre - catalyst and MAO as co - catalyst. Under optimized conditions ([complex] = 2 μmol, Al/Cr = 500, 25 °C, 0.9 MPa ethylene, 30 min), the catalytic activity of complex C1 in toluene is 2.15 × 10 5 g (mol Cr h) −1 and the selectivity for C 6 and C 8 oligomer is 36.76%. In addition, the structure of complexes significantly affects both the catalytic activity and the selectivity on ethylene oligomerization.
研究领域:
化学
·
材料科学
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DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5904
·
IF 3.14
Cuiqin Li,Dan Li,Fengfeng Wang,Yuxin Gao,Jin Huang,Feng Li
Series of hyperbranched PNP ligands ( L1 – L3 ) were prepared using three low-generation hyperbranched molecules with the same branching chains and functional groups but different alkyl chain length as backbones in a mixed solvent of acetonitrile and dichloromethane. The chromium complexes ( Cr1 – Cr3 ) were obtained by reacting with CrCl 3 (THF) 3 and the corresponding ligands ( L1 – L3 ). Both L1 – L3 and Cr1 – Cr3 were characterized by elemental analysis, Fourier transform infrared and electrospray ionization–mass spectrometry as well as 1 H nuclear magnetic resonance (NMR) and 31 P NMR measurements in the case of the ligands. When activated with different aluminum co-catalysts, all three chromium complexes were able to catalyze the ethylene oligomerization, but the products of the ethylene oligomerization were mainly dependent on ethylene pressure, co-catalyst and ligand backbone. Upon activation with methylaluminoxane, the catalytic activity and the selectivity of C8 olefin increased with increasing of ethylene pressure for Cr1 , the catalytic activity was 13.83 × 10 5 g·(mol Cr·h) −1 and the main product was C8 olefin (50.68%) at the ethylene pressure of 4.0 MPa. When activated with diethylaluminium chloride, ethylaluminium dichloride and ethylaluminum sesquichloride, Cr1 showed the lower catalytic activity and the higher selectivity of C4 olefin in toluene. An increase in the length of alkyl chain in the hyperbranched PNP ligand backbone caused a decrease in the catalytic activity and an increase in the selectivity of C8 + olefin. The PNP chromium complexes exhibited higher selectivity for higher carbon number olefins compared with the dendritic PNP chromium complex ( Cr5 ).
研究领域:
化学
·
材料科学
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Mookan Natarajan,Xueming Li,Wei Zhong,Wei Wang,Zhiyin Xiao,Xiujuan Jiang,Chunxin Lu,Xiaoming Liu
Three half-sandwiched iron(II) monocarbonyl cationic complexes ( 1 + − 3 + ) containing a azadiphoshine ligand (PNP, L 1 – 3 ) and an iodide as the counter anion, [Fe(II)Cp(CO)( L 1 – 3 )]Ι (Cp = η 5 -cyclopentadienyl; L 1 = Ph 2 PN(cyclohexyl)PPh 2 , 1 + ; L 2 = Ph 2 PN(phenyl)PPh 2 , 2 + ; L 3 = Ph 2 PN(benzyl)PPh 2 , 3 + ) were reported. All the complexes were fully characterized, of which complexes 2 + and 3 + were crystallographically analysed to confirm their “piano stool” geometry. Electrochemically, complexes 1 + − 3 + exhibited two major reduction events at about −1.9 V and −2.3 V, respectively, assigned to Fe(II) → Fe(I) and Fe(I) → Fe(0), respectively. The first reduction produces a 19e-species, [Fe(I)Cp(CO)( L 1 – 3 )] ( 1, 2 , and 3 ) whereas the second event is not assigned to the further reduction of the 19e-species but a 17e-intermediate ([Fe(I)Cp(CO)( m - L 1 – 3 )]; 1′, 2′ and 3′ ) which is chemically generated from the 19e-species by cleaving one of the two Fe−P bonds. However, the 19e-species 3 is considerably more stable than the other two analogues ( 1 and 2 ) due to H − π interaction between the ortho -H atoms from one of the four phenyl rings on the phosphine atom and the phenyl ring of the benzyl group as revealed by theoretic calculations. Therefore, species 3 is stable enough for the reduction of 3 → 3 − to be electrochemically detected right before the second major reduction. To further shed some light on the electrochemical mechanism, both bulk electrolysis and chemical reduction of complexes 1 + − 3 + with cobaltocene as the reducing agent were conducted. Under N 2 atmosphere, the neutral 17e-species, [Fe(I)Cp(CO)( m - L 1 – 3 )] ( 1′ - 3′ ) was spectroscopically detected whereas under CO atmosphere, CO-adducts, [Fe(I)Cp(CO) 2 ( m - L 1 – 3 )], were generated. The formation of CO-adduct explains the loss of reversibility of the first reduction ( 3 + ) under CO atmosphere in its electrochemistry. With acetic acid as the proton source, only the second major reduction of the complexes exhibited significant catalytic activity, of which complex 1 + possessed the best performance. Significant proton-coupled electron transfer (PCET) effect was observed for complex 1 + due to the strong electron-donating capability of the ligand ( L 1 ).
研究领域:
无机化学
·
催化化学
·
电化学
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Jingjing Zhai,Fen You,Suting Xu,Ao Zhu,Xiaohui Kang,Yat-Ming So,Xiaochao Shi
A PNP-pincer ligand provides a versatile ligation framework, which is highly useful in organometallic chemistry and catalytic chemistry. In this work, by a de novo strategy, a simple and efficient synthetic pathway, has been developed to prepare the new iminodibenzyl-based PNP pincer proligand imin-RPNP(Li or H) (R = isopropyl, phenyl). By employing salt metathesis or direct alkyl elimination, we successfully synthesized a series of iminodibenzyl-PNP rare-earth-metal (Ln = Sc, Y, Dy, Ho, Er, Tm, Lu) complexes and characterized them by NMR and X-ray diffraction analyses. Upon addition of a borate and triisobutylaluminum (TIBA), the rare-earth-metal complexes 2-Y, 2-Dy, 2-Ho, 2-Er, and 2-Tm bearing the imin-PhPNP ligand exhibited unexpectedly high 3,4-selectivity (up to 95%) for the polymerization of 1,3-dienes (isoprene and myrcene); in particular, the chosen yttrium complex 2-Y promoted the 1,3-diene polymerization in a living manner. A computational study suggested that the sterically congested configuration around the metal center imposed by the imin-RPNP ligand might be the main reason for this unusual selectivity.
研究领域:
有机金属化学
·
催化化学
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Zhiyin Xiao,Mookan Natarajan,Wei Zhong,Xiaoming Liu
In this work, four complexes of Co(II) and Ni(II), [Co( L 1 ) 2 (CH 3 CN)](ClO 4 ) 2 ( 1 ), [Ni( L 1 ) 2 ](ClO 4 ) 2 ( 2 ), [Co( L 2 ) 2 (CH 3 CN)](ClO 4 ) 2 ( 3 ) and [Ni( L 2 ) 2 ](ClO 4 ) 2 ( 4 ) were synthesized by reacting the perchlorate hydrate of M(II) (M = Co and Ni) with the ligands, Ph 2 PN(cyclohexyl)PPh 2 ( L 1 ) and Ph 2 PN(pyridin-2-ylmethyl)PPh 2 ( L 2 ), respectively. The complexes were fully characterized, and their absolute structures were determined using X-ray single crystallographic analysis. The cobalt complexes ( 1 and 3 ) exhibited two reductions in acetonitrile , one reversible reduction at about −0.65 V and the other at about −2.0 V at which catalytic reduction of proton was observed. The two reductions were assigned to Co(II) → Co(I) and Co(I) → Co(0) processes, respectively. The reduction of Ni(II) → Ni(I) was negatively shifted by about 300 mV compared to the cobalt analogues and the process showed two closely located reversible reductions due to geometric isomerization between the square planar ( Sp ) and tetrahedral ( Td ) geometries, of which the Td isomer was first reduced due to the lower energy level of its frontier orbitals . The second reduction of the Ni(II) complexes ( 2 and 4 ) was invisible in the potential range examined. Upon addition of acetic acid, it shifted positively by over 300 mV and showed catalysis on proton reduction. The shift was attributed to proton-coupled electron transfer (PCET) effect which was further enhanced by the pendant pyridyl group in ligand L 2 . The nickel complexes showed much higher activity than cobalt analogues in the catalysis on proton reduction and the pendant base group could synergistically enhance the activity of the complex ( 4 ).
研究领域:
无机化学
·
电化学
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Yuanjian Liu,Yan Qi,Panpan Liu,Yusong Wan,Fengyang Wang,Yunlong Liu,Xiaohui Xiong
Herein, a novel bipolar electrode-electrochemiluminescence (BPE-ECL) biosensing strategy was developed, engineered to achieve highly and pathogen-specific detection of Escherichia coli O157:H7 ( E. coli O157:H7) through enzymatic cascade signal transduction. Crucially, this strategy employs β-galactosidase (β-gal) activity as a biomarker signature, wherein the enzymatic hydrolysis of p -nitrophenyl-β-D-galactopyranoside (PNPG) generates electroactive intermediates, p-nitrophenol (pNP). The pNP undergoes a six-electron reduction reaction at the closed BPE cathode electrode and simultaneously oxidizes phosphorus Ru(bpy) 3 2+ at the anode electrode to trigger obvious ECL signal. The ECL signal amplification of enzymatic substrates with mono-, bi-, and tetra-electronic systems is inherently constrained by inefficient electron transfer, resulting in suboptimal sensing performance. In contrast, the PNPG/pNP-based detection platform demonstrates superior sensing capabilities. For indirect quantification of E. coli O157:H7, the ECL intensity was linearly correlated with bacterial concentration. The optimized biosensor, through rigorous tuning of enzymatic catalysis and ECL signal amplification strategies, delivers a wide dynamic range (10(Zhang et al., 2023a 1) –10 6 CFU) and a low detection limit (LOD = 2 CFU) in 200 μL of bacterial samples. The real sample effect was evaluated, and the assay successfully detected E. coli O157:H7 in water, juice, and pure milk. This label-free platform integrates operational simplicity and high specificity, offering a promising solution for on-site monitoring of foodborne pathogens and clinical diagnostics.
研究领域:
生物传感器
·
分析化学
·
微生物学
·
食品安全
·
病原体检测
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Micro & Nano Letters
·
2019
·Vol. 14
·期 2
·163-167
·
IF 0.975
Meiling Yang,Mi Mao,Yu He,Jiangang Zhou,Yili Ge,Gongwu Song
This work integrated zero-valent copper (ZVC) onto the surface of zeolitic imidazolate framework (ZIF) to form hybrids of ZVC/ZIF-8 as a non-noble catalyst for catalytic reduction of PNP as a reliable model reaction. The ZVC/ZIF-8 exhibited superior catalytic properties and good recyclability after the fabrication. 6%ZVC/ZIF-8 hybrids complete the reduction process in 2 min with a rate constant estimated to be 2.39 min −1 . The study’s findings explored a simple and powerful way to incorporate metal ions into the backbones of open framework materials without losing their properties.
研究领域:
材料科学
·
环境化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 13.2
Defang Liu,Chao Wang,Zhuo Cheng,Qiyao Zhao,Xuelian Zeng,Chiyu Wen,Jing Zhao,Guoxiang Zhu,Jun Wang,Yongfa Zhu
p-Nitrophenol (PNP), a widely used chemical intermediate, exhibits stubborn resistance to conventional oxidation treatments due to its high toxicity, electron-deficient nature, and the high stability of its aromatic ring. To address the bottlenecks of low mineralization efficiency of PNP by traditional ozonation and the limited spectral utilization of conventional PCO systems. Herein, we constructed a photocatalytic–ozone synergistic system based on perylene diimide-based organic polymers (Urea-PDI/O 3 /vis). Owing to the broad spectral response of the polymers, the light-responsive range of this coupled system can be extended to the near-infrared region up to 700 nm. The degradation rate of PNP in this system is 25 times higher than that in the photocatalytic system alone and 2.42 times greater than that in the ozone system alone. More importantly, the mineralization efficiency of PNP is significantly enhanced in the Urea-PDI/O 3 /vis, reaching a value three times higher than that of the traditional ozone system. Mechanism investigation reveals that the denitrification efficiency for PNP is comparable between the ozonation and photocatalytic–ozone systems. However, the photocatalytic–ozone process demonstrates a marked superiority in the subsequent ring cleavage and mineralization via decarboxylation of small-molecular organic acids. In contrast to the direct ozonation mechanism dominated by electrophilic and dipolar addition reactions, the Urea-PDI/O 3 /vis efficiently utilizes photogenerated electrons to convert ozone into hydroxyl radicals in large quantities, which enables highly efficient mineralization of PNP. This study will provide new insights into the removal of PNP in water.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Lesly Dasilva Wandji Djouonkep,Huaizhi Tao,Lvyan Zhuo,Alain Pierre Tchameni,Lin Zhao,Binqiang Xie
The field of thermo-thickening polymer interacting with clay has long been shrouded in mystery and ambiguity. Despite numerous studies and investigations, the complex interactions, underlying mechanism and binding forces remain elusive, imposing further exploration and elucidation. In this study, three thermo-thickening polymers such as poly(acrylamide methylpropane sulfonic acid-co-N-vinylcaprolactam) (PNV), poly(acrylamide methylpropane sulfonic acid-co-N,N-dimethylacrylamide) (PDM), and poly(acrylamide methylpropane sulfonic acid-co-N-isopropylacrylamide) (PNP) with clay fluids (CFs) were investigated to gain deeper understanding of the underlying physicochemical interactions. Techniques such as Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance ( 1 H NMR), and elemental analysis (EA) elucidated the structural properties, whereas turbidimetry and rheometric analysis elucidated the temperature-induced phase transitions. The interactions between the different polymer side chains and clay double-sheets were investigated through isothermal adsorption testing, probing chemisorption and hydrogen bonding tuned the chemical properties, whereas electrostatic forces (ionic/van der Waals) bind the physical properties as demonstrated by Zeta (ζ) potential, XRD , high-resolution spectroscopy (XPS), and scanning electron microscopy (SEM) imaging. The addition of 0.2–1.5 wt% of the polymers induced significant effect on the rheological properties of CFs, with increase in low shear viscosity and plastic viscosity, attributed to the formation of gel-like structures at high temperatures. PNV/Clay (NVBF)-modified fluid demonstrated exceptional fluid thickening and suspension behaviors compared to linear PDM/Clay (DMBF) and PNP/Clay (NPBF)-modified fluids. In addition, NVBF exhibited significantly higher adsorption energies and basal spacings, along with more crystalline patterns suited to embed clay particles. Overall, the synergistic effect of the different polymer side chains with clay particles provides valuable insights on the mechanistic and enhancement of rheological properties of CFs effective as shale inhibition, viscosifier and wellbore stabilization.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 24
·25286-25300
·
IF 2.914
Liu Fang,Che Yangli,Chai Qingwen,Zhao Mengfei,Lv Yan,Sun Hui,Wang Yongqiang,Sun Juan,Zhao Chaocheng
Copper and zinc composite oxides (Cu 2 O/ZnO) were synthesized by an impregnation-reduction-air oxidation method. A series of Cu 2 O/ZnO/rGO ternary composites were prepared by coupling with graphene oxide (GO) with different mass fractions in a solvothermal reaction system. The microscopic morphology, crystal structure, and optical characteristics of the photocatalysts were characterized. The degradation of p-Nitrophenol (PNP) and polyacrylamide (PAM) by photocatalytic materials under simulated solar irradiation were studied, and the degradation kinetics were also investigated. The results showed that cubic Cu 2 O was modified by ZnO nanorods and distributed on rGO nanosheets. The ternary Cu 2 O/ZnO/rGO nanocomposites have stronger simulated solar absorption ability and higher photodegradation efficiency than pure ZnO and binary Cu 2 O/ZnO nanocomposites. When the amount of Cu 2 O/ZnO/rGO-10 was 0.3 g L −1 , the degradation rate of 10 mg L −1 PNP reached 98% at 90 min and 99.6% of 100 mg L −1 PAM at 30 min. The photocatalytic degradation processes of PNP and PAM all followed the pseudo-first-order kinetic model. Free radical trapping experiments showed that superoxide radicals were the main active substances to improve photocatalytic efficiency. In addition, after four recycles, the catalytic efficiency of Cu 2 O/ZnO/rGO-10 was still over 90%. It showed that Cu 2 O/ZnO/rGO-10 was a promising catalyst for wastewater treatment because of its good photostability and reusability.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 35
·20323-20331
·
IF 3.049
Jiangkun Du,Yang Wang,Faheem,Tiantian Xu,Han Zheng,Jianguo Bao
H2O2 and persulfate (PDS) activated by iron are attracting much attention due to their strong oxidation capacity for the effective degradation of organic pollutants. However, they face problems such as requiring an acidic reaction pH and difficulty of Fe2+ regeneration. In this study, the simultaneous activation of H2O2 and persulfate by nanoscaled zero valent iron (nZVI) was investigated for the degradation of p-nitrophenol (PNP). The nZVI/H2O2/PDS oxidation system exhibited significantly higher reactivity toward PNP degradation than the systems with a single oxidant. A synergistic effect was explored between H2O2 and PDS during nZVI-mediated activation, and the molar ratio of H2O2/PDS was a key parameter in optimizing the performance of PNP degradation. The nZVI/H2O2/PDS system could function well in a wide pH range, and even 95% PNP was removed at an initial pH 10, thus markedly alleviating the pH limitations of Fenton-like processes. Both hydroxyl radicals and sulfate radicals could be identified during H2O2/PDS activation, in which H+ produced during PDS decomposition promoted H2O2 activation. The increase of oxidant concentration could significantly enhance the PNP degradation, while the presence of HCO3− and HPO42− exerted great inhibition. Furthermore, five degradation intermediates of PNP were detected and its degradation pathways in the nZVI/H2O2/PDS system were presented. This study reveals that the simultaneous activation of H2O2 and PDS by nZVI is a promising advanced oxidation tool as an alternative to typical Fenton processes for recalcitrant pollutant removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2025
·
IF 2.1
Jinzhe Wang,Hongliang Huo,Lili Ma,Xue Zhai,Feng Li,Zhiqiu Zhang,Cuiqin Li
PNP chromium complex (PNP-Cr) with high selectivity of high-carbon α-olefins in ethylene oligomerization was synthesized to modify nano-SiO2 to obtain heterogeneous PNP chromium catalyst (PNP-Cr@SiO2) with high dispersibility of catalytic active centers. Upon activation with methylaluminoxane (MAO), PNP-Cr@SiO2 had a high catalytic activity of 1.13 × 105 g/(mol Cr·h) and the selectivity of 79.98% for C8+ α-olefins in ethylene oligomerization. Moreover, PNP-Cr@SiO2 had remarkable recyclability and catalytic stability compared with the corresponding homogeneous catalyst (PNP-Cr), and the catalytic activity decreased to 0.95 × 105 g/(mol Cr·h) and the selectivity for C8+ α-olefins slightly decreased to 78.86% after three cycles. Grey relational analysis confirmed that reaction pressure and reaction temperature were the main factors affecting the catalytic activity of PNP-Cr@SiO2 and the selectivity for high-carbon α-olefins in ethylene oligomerization. PNP-Cr@SiO2 had higher selectivity for C8+ α-olefins because the catalytic active centers were primarily distributed on the surface of nano-SiO2 to facilitate the formation of large metallacycle and the insertion of the oligomer (1-octene) into the metallacycle compared with other heterogeneous catalysts.
研究领域:
催化化学
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有机金属化学
·
高分子化学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）