CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Yahao Dong,Jiajun Bi,Shujun Ming,Shoute Zhang,Dajian Zhu,Di Meng,Tao Li
Chitosan is a versatile polysaccharide in different domains due to facile modification and good biodegradability. In this paper, taking advantage of such functional properties, we have developed a stabilizer agent [OCMCS-SB] produced from chitosan, and palladium was successfully immobilized on this designed stabilizer [OCMCS-SB-Pd(II)]. The obtained complex was illuminated by 13 C CP-MAS NMR, FT-IR, TGA, XRD, XPS, SEM, TEM and ICP-OES analyses. Due to the interactions of primary hydroxyl groups on chitosan, Schiff base and carboxy groups, the Pd complex showed excellent reactivity (up to 99 %) and stability towards Suzuki reactions in eco-friendly medium. Subsequently, the reusability experiments for OCMCS-SB-Pd(II) formed from chitosan were examined in five consecutive cycles, which showed no appreciable decrease in activity. Furthermore, a reasonably trifunctional complex structure was proposed. The present bio-based system offers a promising approach in utilizing such biopolymers in organic transformations.
研究领域:
生物化学
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有机化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2013
·Vol. 3
·期 44
·21863-21868
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IF 2.562
Ningzhao Shang,Shutao Gao,Cheng Feng,Haiyan Zhang,Chun Wang,Zhi Wang
In this paper, an N-heterocyclic carbene–palladium complex (NHC-Pd2+) was immobilized onto the surface of graphene oxide via a chemical bonding method for the first time. The resultant graphene oxide supported NHC–Pd2+ composite (GO supported NHC-Pd2+) was characterized by transmission electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. It was demonstrated that the GO supported NHC-Pd2+ can act as an efficient catalyst for Suzuki–Miyaura coupling reactions. The yields of the products were in the range of 83% to 96%. The catalyst can be readily recovered and reused for at least 6 consecutive cycles without any significant loss in catalytic activity.
研究领域:
材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2019
·Vol. 12
·期 5
·1376-1384
·
IF 4.495
Wen-Di Guo,Lei Liu,Shu-Qing Yang,Xiao-Chao Chen,Yong Lu,Giang VO-Thanh,Ye Liu
Graphical Synergetic catalysis : The one-pot tandem bis-alkoxycarbonylation of alkynes was accomplished over the bi-functional catalytic system containing Xantphos-modified Pd-complex and Lewis super-acid of Al(OTf) 3 . Via the synergetic catalysis, the involved Xantphos-modified Pd-complex was responsible for the activation of CO and the alkynes through coordination to Pd-center while Al(OTf) 3 was in charge of the activation of the alcohol to facilitate the formation of [Pd−H] + active species. Tandem bis-alkoxycarbonylation of alkynes allows for the preparation of 2-substituted succinates from alkynes and nucleophile alcohol via two successive alkoxycarbonylation with advantages of 100 % atomic economy and simplified one-pot operation. Herein, the one-pot tandem bis-alkoxycarbonylation of alkynes was accomplished over the bi-functional catalytic system containing Xantphos-modified Pd-complex and Lewis super-acid of Al(OTf) 3 . It was found that, via the synergetic catalysis, the involved Xantphos-modified Pd-complex was responsible for the activation of CO and the alkynes through coordination to Pd-center while Al(OTf) 3 was in charge of the activation of the alcohol to facilitate the formation of [Pd−H] + active species. The in situ high-pressure FT-IR analysis, coupled with 1 H/ 13 C NMR spectral characterizations, confirmed that the introduced Al(OTf) 3 with intensive oxophilicity (via acid-base pair interaction) was able to activate nucleophilic MeOH to be a reliable proton-donor ( i. e . hydride-source) to warrant the formation and stability of [Pd−H] + species upon the oxidation of Pd 0 by H + (Pd 0 +H + →[Pd II −H] + ). Over the developed bi-functional catalytic system, the yields of the target diesters were obtained in the range of 36∼86 % in this sequence with the wide substrate scope.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Xinjuan Li,Zhangquan Zhou,Yanan Wang,Jiaxin Dong,Xianbin Jia,Zhiguo Hu,Qingcong Wei,Weiwei Zhang,Yuqin Jiang,Jiaojiao Zhang,Yahao Dong
Starch can be used in diverse fields because it is a readily available, non-toxic polysaccharide with adaptable functionality and biodegradability . In this study, taking the aforementioned characteristics into consideration, we designed a modified starch (Starch-SB), which serves as supporting material for palladium stabilization. This new air and moisture-stable robust palladium composite [Starch-SB-Pd(II)] was characterized by FT-IR, XRD, TGA , XPS , SEM, EDX , TEM , CP/MAS 13 C NMR, and ICP-MS analytical techniques. The catalytic studies exhibit high activity (up to 99 %) and stability in Suzuki cross-coupling reactions for this starch supported catalytic system under mild conditions (lower reaction temperature and green solvents) because of the cooperative interactions of multifunctional capturing sites on starch (Schiff base, hydroxy and amine groups) with palladium species. The experiments on reusability demonstrate that Starch-SB-Pd(II), which was prepared from functionalized starch, could be readily recycled several cycles through centrifugation . Moreover, we proposed a possibly multifunctional complex structure. This work presents an appealing and intriguing pathway for the utilization of polysaccharide as crucial support in green chemical transformations.
研究领域:
生物化学
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材料科学
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绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2017
·
IF 13.858
Xingzhong Zhu,Hang Kuen Yip,Xiaolu Zhuo,Ruibin Jiang,Jianli Chen,Xiao-Ming Zhu,Zhi Yang,Jianfang Wang
The synthesis of metal nanostructures with plasmon wavelengths beyond ∼1000 nm is strongly desired, especially for those with small sizes. Herein we report on a AgPd-tipping process on Au nanobipyramids with the resultant red plasmon shifts reaching up to ∼900 nm. The large red plasmon shifts are ascribed to the deposition of the metal at the tips of Au nanobipyramids, which is verified by electrodynamic simulations. The method has been successfully applied to Au nanobipyramids and nanorods with different longitudinal dipolar plasmon wavelengths, demonstrating that the plasmon wavelengths of these Au nanocrystals can be extended to the entire near-infrared region. Pt can also induce the tipping on Au nanobipyramids and nanorods to realize red plasmon shifts, suggesting the generality of our approach. We have further shown that the metal-tipped Au nanobipyramids possess a high photothermal conversion efficiency and good photothermal therapy performance. This study opens up a route to the construction of Au nanostructures with plasmon resonance in a broad spectral region for plasmon-enabled technological applications.
研究领域:
材料科学
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纳米技术
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-9
·
IF 5.578
Wang Liyuan,Feng Feng,Ma Zhanfang
Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl 4 and Na 2 PdCl 4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at −0.65 V, −0.3 V, 0.12 V and 0.5 V, respectively. Meanwhile, these composites showed high H 2 O 2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724) and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2017
·Vol. 164
·期 6
·B285
·
IF 3.259
Xuan Shen,Xiaohong Xia,Yongling Du,Weichun Ye,Chunming Wang
AuPd bimetallic composite has been prepared on reduced graphene oxide/polyimide (PI/RGO) film by electrodeposition. The AuPd fabricated on PI/RGO film exhibits good conductivity and excellent catalytic properties. AuPd/PI/RGO electrode shows high activity toward hydrogen peroxide (H2O2) for coupling effect between AuPd and PI/RGO film. Based on high electrochemical activity toward H2O2, an amperometric glucose biosensor has been also described, which was achieved by the immobilization of glucose oxidase (GOx) onto the AuPd/PI/RGO electrode. The proposed biosensor displayed good amperometric response characteristics toward glucose, such as a fast response within 3 s and a wide linear range from 0.024 mM to 4.6 mM. In addition, the biosensor was utilized for the detection of glucose in human blood serum that displayed satisfactory results. The present finding might open up a new avenue in the development of high performance bimetallic materials on appropriate supporting materials for electrochemical sensing.
研究领域:
生物传感技术
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材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Luming Wang,Guoliang Zhang,Hui Zhao,Gang Wang,Zengxi Li,Chunshan Li
With the development of green chemistry, researchers are eager to develop separable and recyclable catalyst for methyl propionate production through ethylene hydroesterification. Herein, a novel zeolite-encapsulated Pd complex was developed for ethylene hydroesterification with CO and methanol to methyl propionate. The introduced Pd component is coordinated with 1, 2-bis (di- tert -butyl phosphinomethyl) benzene ligand to form Pd complex, which is encapsulated in USY zeolite. This scheme solves the challenge of coupling phosphine-palladium complexes with acid promoters as heterogeneous catalysts. It was found that the increasing density of Brønsted acid sites on USY zeolite favors the ethylene hydroesterification. Furthermore, the influences of catalyst preparation and reaction conditions on the catalytic performance were assessed. As a result, the ethylene conversion could reach 99 % with MP selectivity of 100 % under the optimal condition. In addition, the catalytic heterogeneity and stability of zeolite-encapsulated Pd complex were investigated.
研究领域:
催化化学
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绿色化学
✓ 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）