ANALYST
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2022
·Vol. 147
·期 7
·1341-1347
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IF 5.227
Chen-Chen Jiang,Xiao-Chong Li,Jian-Ang Fan,Jia-Ying Fu,Xu-Nan Huang-Fu,Jia-Jie Li,Ju-Fang Zheng,Xiao-Shun Zhou,Ya-Hao Wang
The electroreductive cleavage of carbon–halogen bonds has attracted increasing attention in both electrosynthesis and pollution remediation. Herein, by employing the in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique, we have successfully investigated the electroreductive dehalogenation process of aryl halides with the thiol group on a smooth Au electrode in aqueous solution at different pH values. The obtained potential-dependent Raman spectra directly reveal a mixture of the reduction products 4,4′-biphenyldithiol (BPDT) and thiophenol (TP). The conversion ratios of the C–Cl and C–Br bonds at pH = 7 are 37% and 55%, respectively. Furthermore, quantitative analysis of the intensity variations of ν(C–Cl), ν(C–Br) and aromatic ν(CC) stretching modes suggests electroreductive dehalogenation via both direct electron transfer reduction and electrocatalytic hydrodehalogenation. Molecular evidence for the C–C cross coupling process through TP reaction with benzene free radical intermediates is found at negative potentials, which leads to the increasing selectivity of biphenyl products.
研究领域:
电化学
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
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2020
·
IF 3.83
Fangyi Huang,Hua Su,Yulan Jing,Yuanxun Li,Qihai Lu,Xiaoli Tang
Herein, glass-free microwave dielectric ceramics CaMg 0.9-x Li 0.2 Zn x Si 2 O 6 (x = 0–0.36) with excellent microwave dielectric properties were prepared via traditional solid-state reaction method. Phase composition and crystalline structure were identified using X-ray diffraction (XRD), which confirmed that the ceramics contained more than one phase. Rietveld refinement method was utilized to analyze XRD data and obtain structural information, such as lattice parameters. SEM photographs showed that Zn 2+ substitution could effectively promote densification of the ceramics. Microwave dielectric properties were obviously influenced by the combination of multiple phases. Combined with Raman spectra, influences of Raman shift and FWHM of vibration peaks on microwave dielectric properties were determined. The CaMg 0.9-x Li 0.2 Zn x Si 2 O 6 ceramic exhibited high performance at x = 0.28 with: Q × f = 68,190 GHz, ε r = 7.51 and τ f = −68 ppm/°C, when sintered at 900 °C. The studied ceramics are promising candidates for LTCC application.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Lei Jin,Zhi-Hao Liang,Jia-Qiang Yang,An-Ni Zheng,Zhao-Yun Wang,Fang-Zu Yang,De-Yin Wu,Zhong-Qun Tian,Dongping Zhan
5,5-Dimethylhydantoin (DMH), as a heterocyclic compound with N and O atoms, is an excellent complexing agent for trivalent gold ions . In this work, the tautomeric structures of DMH at different pH values in the solution are determined via theoretical calculations and Raman spectra . Only the ketonic form of DMH exists in weakly acidic and neutral mediums, and only the enolic form of DMH exists in highly alkaline mediums. In the weakly alkaline medium of pH 9, a large number of ketonic forms and a small number of enolic forms coexist. The coordination behavior between DMH and Au(Ⅲ) is clarified in the weakly alkaline medium of pH 9. The DMH in ketonic form is fully coordinated with Au(Ⅲ) at pH 9 and the optimal coordination structure is N2-Au with an N-Au bond energy of 16.17 eV. The electrochemical study reveals that Au(DMH) 4 − coordination ions are in the two-step electro-reductions with the first Au(Ⅲ) to Au(Ⅰ) and the second Au(Ⅰ) to Au on the gold electrode surface. The EC-SERS experiments further verify the interfacial process of tautomeric structures and Au(DMH) 4 − coordination ions.
研究领域:
化学
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材料科学
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电化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2017
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IF 2.714
Zhongchuan Peng,Huayi Li,Qian Li,Youliang Hu
Carbon nanoforms (CNFs, including graphene, carbon nanotube and fullerene) were functionalized via microwave-assisted thiol-ene click chemistry. Different functional CNFs with −COOH, −NH 2 , −NH 3 Cl,-Si(OCH 3 ) 3 , alkyl and furyl groups were obtained and characterized by XPS, EDS, TGA, Raman spectroscopy and MALDI-TOF MS. Microwave was much more efficient to promote reactions than traditional thermal method. XPS confirmed the binding energy of C-S-C (163.3ev) the modified CNFs. Raman spectroscopy showed increasing I D /I G and A D /A G of graphene and CNT after thiol-ene addition reaction. The result of MALDI-TOF MS indicated that the thiol-containing molecules were attached on fullerene. All these results indicated the successful thiol-ene click reactions between CNFs and thiol-containing molecules under microwave. TGA analysis results showed the mass loss of the modified CNFs, which provided that AIBN and 3-merlaptopropionic acid were the most efficient initiator and monomer, respectively. In summary, the microwave-assisted thiol-ene click reaction provided a powerful chemical tool for the preparation of functional CNFs materials.
研究领域:
材料科学
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化学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Zhitao Shan,Yuanyuan Kang,Jiayan Zhang,Yanfei Zhang,Qiuju Zheng,Shujiang Liu,Haizheng Tao,Yuanzheng Yue
The hardness ( H v ) and crack initiation resistance ( C R ) of oxide glasses are crucial properties for various applications, such as in vehicles, display devices, and buildings. However, these properties are still limited for many special applications. Here, we studied the evolution of the H v and C R with varying the ratio R = [Al 2 O 3 ]/[CaO] in the low silica (0 and 17 mol% SiO 2 ) aluminate glasses, i.e., so called silico-aluminate glasses, and thereby identified a composition that exhibits the highest C R and H v . The results showed that the H v decreased with increasing R within the peraluminous region. Furthermore, a significant increase in C R value with increasing R was detected in the range of R = 1.0–1.18. In contrast, the glass series containing 50 mol % SiO 2 content exhibited only a slight increase in C R value, but pronounced increases in both T g and H v with increasing R in the peraluminous region. The Raman spectroscopy revealed that [5]Al and oxygen tri-cluster ([3]O) are the controlling factors for C R and H v of the studied glasses. Moreover, the impact of [3]O and [5]Al on H v and C R is highly dependent on the SiO 2 content in the studied glasses.
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高影响因子
Biomedical Optics Express
·
2019
·Vol. 10
·期 4
·1581-1600
·
IF 3.91
Ping Tang,Wendai Cheng,Xuanmeng He,Qinnan Zhang,Jing Zhong,Xiaoxu Lu,Shengde Liu,Liyun Zhong
Berberine (BBR), a traditional Chinese herb extract medicine, reveals some anticancer effects in leukemia, but it remains controversial about the molecular mechanism of BBR-induced leukemia cell apoptosis. In this study, combining Raman spectrum and spectral imaging, both the biochemical changes of BBR-induced Jurkat cell apoptosis and the precise distribution of BBR in single cell are presented. In contrast, we also show the corresponding results of Jatrorrhizine (JTZ) and Palmatine (PMT), two structural analogues of BBR. It is found that all three structural analogues can induce cell apoptosis by breaking DNA and the main action sites are located in phosphate backbone and base pair groups, but their action on cell cycle are different, in which BBR leads to the S phase arrest while JTZ and PMT are on the G2 phase arrest. Moreover, from the Raman spectra of DNA treated with different drugs, we find that the content of phosphate backbone and base pair groups in BBR-treated DNA are larger than those in JTZ or PMT. And this result reflects the strong capability of BBR breaking DNA backbone relative to JTZ or PMT, suggesting that the existence of methylene-dioxy on the 2, 3 units of A ring on the quinoline ring can greatly enhance the capability of BBR breaking DNA backbone, so the action effect of BBR-induced Jurkat cell apoptosis is better than those of PMT or JTZ. Further, by using Raman spectral imaging approach, we achieve the precise distribution of BBR in single cell, it is found that the receptor-mediated BBR targeting delivery based single-wall carbon nanotube and folic acid (SWNT/FA) reveals excellent performance in BBR targeting delivery relative to the conventional BBR diffusion approach. Importantly, these results demonstrate that Raman spectrum and spectral imaging should be a powerful tool to study the molecular mechanism of drug-induced cell apoptosis and evaluate the efficiency of drug delivery system.
研究领域:
生物医学
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药理学
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分子生物学
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DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Zhongwen Dong,Chuanyu Yang,Dongpu Zhao,Yanan Wang,Weifeng Chu,Zhaochi Feng,Xiangxue Zhu,Wenjie Xin,Yongchen Shang,Shenglin Liu,Longya Xu
The interzeolite transformation approach has been used extensively for the quick synthesis of zeolites at a lower cost. Herein, an interzeolite transformation method for the quick synthesis of co-crystalline ZSM-5/ZSM-11 (CDM-5) nanoaggregates has been developed by precisely controlling the synthesis parameters and using 1,6-hexamethylenediamine as an organic structure-directing agent. In contrast, the irregular CDM-5 zeolite block obtained from an amorphous aluminosilicate gel takes a longer crystallization time using the conventional method. Combined with the related results of characterization, UV-Raman spectra show that double 6-membered rings in the parent USY zeolite framework are broken, and an ordered aluminosilicate aggregate species (OAAS) containing 4-membered rings (4Rs) are formed during the interzeolite transformation. HRTEM and SEM images demonstrate that the block OAAS is dissolved into amorphous nanoparticles, followed by converting into CDM-5 nanoaggregates. These results reveal that an OAAS is essential for the synthesis of CDM-5 nanoaggregates via the interzeolite transformation method. In addition, the CDM-5 nanoaggregate catalyst exhibits superior stability and resistance to carbon deposition in the alkylation reaction of benzene with ethanol compared with the irregular block CDM-5 catalyst.
研究领域:
化学工程
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材料科学
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催化
·
纳米技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）