ACS Sustainable Chemistry & Engineering
·
2015
·
IF 4.642
Yunlei Zhang,Jianming Pan,Yating Shen,Weidong Shi,Chunbo Liu,Longbao Yu
Employing renewable and widely available feedstock of cellulose as a raw material for 5-hydroxymethylfurfural (HMF) production opens up the possibility of sustainable biorefinery schemes that do not compete with the food supply. In this work, novel and efficient Brønsted acidic polymer nanotubes were successfully prepared by chemical conjugating grafting −SO3H groups onto the surface of polydivinylbenzene (PDVB) nanotubes, which were derived from cationic polymerization of divinylbenzene. By simply adjusting the grafting amounts of hydrophilic −SO3H groups, catalysts with varied hydrophobic and hydrophilic surface wettability (i.e., catalyst-110° and catalyst-10°) could be obtained. It was demonstrated that as-prepared catalyst-10° possessed the higher strong (143 μmol g–1), very strong (614 μmol g–1), and total acidity (786 μmol g–1) than those of catalyst-110°. Besides, the catalytic performance of the synthesized catalyst-110° and catalyst-10° were investigated and compared for the conversion of cellulose to HMF in an ionic liquid (i.e., 1-ethyl-3-methyl-imidazolium chloride, [EMIM]-Cl) system. Particularly, catalyst-110° exhibited the highest HMF yield of 34.6% on a molar basis, which was comparable with that of catalyst-10° (i.e., 37.1%), indicating that its hydrophobic nature was beneficial for decreasing side-reaction of HMF which tend to convert to some other byproducts during the very one-pot reaction. Furthermore, both catalysts can be easily recovered and reused for at least four times without significant loss of their catalytic activities. This work was the continue efforts for fabrication and application solid catalyst for excellent conversion of one-pot cellulose to HMF.
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Chemistry-An Asian Journal
·
2013
·Vol. 8
·期 7
·1504-1513
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IF 4.572
Si-Hai Wu,Yu-Wu Zhong,Jiannian Yao
Graphical NN-CNN breaking news : 2,3-Di(2-pyridyl)-5-phenylpyrazine, which is able to bind two metals through a NN-CNN-type coordination mode, has been designed and synthesized. A RuPt heterobimetallic complex with this bridging ligand shows near-infrared emission at 750 nm, with a quantum yield of 0.41 % and an excited-state lifetime of 170 ns. en This link goes to a English section zh This link goes to a English section A new bridging ligand, 2,3-di(2-pyridyl)-5-phenylpyrazine (dpppzH), has been synthesized. This ligand was designed so that it could bind two metals through a NN-CNN-type coordination mode. The reaction of dpppzH with cis -[(bpy) 2 RuCl 2 ] (bpy=2,2′-bipyridine) affords monoruthenium complex [(bpy) 2 Ru(dpppzH)] 2+ ( 12+ ) in 64 % yield, in which dpppzH behaves as a NN bidentate ligand. The asymmetric biruthenium complex [(bpy) 2 Ru(dpppz)Ru(Mebip)] 3+ ( 23+ ) was prepared from complex 12+ and [(Mebip)RuCl 3 ] (Mebip=bis( N -methylbenzimidazolyl)pyridine), in which one hydrogen atom on the phenyl ring of dpppzH is lost and the bridging ligand binds to the second ruthenium atom in a CNN tridentate fashion. In addition, the RuPt heterobimetallic complex [(bpy) 2 Ru(dpppz)Pt(CCPh)] 2+ ( 42+ ) has been prepared from complex 12+ , in which the bridging ligand binds to the platinum atom through a CNN binding mode. The electronic properties of these complexes have been probed by using electrochemical and spectroscopic techniques and studied by theoretical calculations. Complex 12+ is emissive at room temperature, with an emission λ max =695 nm. No emission was detected for complex 23+ at room temperature in MeCN, whereas complex 42+ displayed an emission at about 750 nm. The emission properties of these complexes are compared to those of previously reported Ru and RuPt bimetallic complexes with a related ligand, 2,3-di(2-pyridyl)-5,6-diphenylpyrazine. en This link goes to a English section zh This link goes to a English section 1
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INDUSTRIAL CROPS AND PRODUCTS
·
2016
·
IF 3.449
Yetao Jiang,Wei Chen,Yong Sun,Zheng Li,Xing Tang,Xianhai Zeng,Lu Lin,Shijie Liu
5-(Hydroxymethyl)furfural (HMF) is an important platform chemical, but the large scale production is limited by its instability. In this research, 5-[(formyloxy)methyl]furfural (FMF), derived from HMF, was produced directly from cellulose in formic acid reaction system with a yield of 33.4 mol% at 150 °C for 2 h. Among numerous metal salt catalysts screened in this study, alkali metal bromides were found to be effective in catalyzing cellulose conversion to FMF. Bromide anions facilitation of the esterification of HMF to form FMF was confirmed. In addition, the effects of water, acid and other reaction parameters also were investigated when NaBr was used as the catalyst. Up to 2% of water or acid in this reaction system did not impact on the FMF yield. Increasing the temperature for every 20 °C from 130 °C to 170 °C halved the reaction time but did not change the maximum yield. FMF was more hydrophobic and thermostable than HMF, which made it easier to be recovered. In a two-step process, FMF with a recovery of 29.4 mol% and purity of 97 mol% was obtained.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2014
·Vol. 52
·期 19
·2715-2724
·
IF 3.245
Jizhen Zhang,Aihua Li,Huihui Liu,Dongjiang Yang,Jingquan Liu
A recyclable solid-state photoinitiator based on the surface modified niobium hydroxide is prepared and successfully introduces into reversible addition–fragmentation chain transfer (RAFT) polymerization under visible light illumination. It is revealed by gel permeation chromatography analysis that well-defined polymers with controlled molecular weight and narrow polydispersity index can be achieved when the feed ratio of photoinitiator to the RAFT agent was controlled properly. It is also found that the polymerization is highly responsive to external stimulus and when light is removed from the system polymerization stops almost immediately. In addition, the photoinitiator can be recycled and reused to initiate the polymerization for many times without significant decrease of initiation efficiency. At last, the mechanism for the light initiated polymerization is proposed to illuminate how the initiation and chain propagation proceed. This facile, green and visible light initiation methodology could attract more and more applications in polymer science with the depletion of fossil energy. A recyclable solid-state photoinitiator based on the surface modified niobium hydroxide was prepared and successfully introduced into reversible addition–fragmentation chain transfer (RAFT) polymerization under visible light illumination. It is revealed that well-defined polymers with controlled molecular weight and narrow polydispersity index (PDI) can be achieved when the feed ratio of photoinitiator to the RAFT agent was controlled properly. It is also found that the polymerization is highly responsive to light initiation. In addition, the photoinitiator can be recycled and reused to initiate the polymerization for many times without significant decrease of initiation efficiency. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 2715–2724
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APPLIED CATALYSIS A-GENERAL
·
2014
·
IF 3.674
Xiuquan Jia,Jiping Ma,Min Wang,Zhongtian Du,Fang Lu,Feng Wang,Jie Xu
The promoted effect of Cu(NO 3 ) 2 on aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) catalyzed by VOSO 4 in acetonitrile was intensively investigated. It was revealed that Cu(NO 3 ) 2 facilitated the activation of VOSO 4 to generate active V 5+ species via the generation of NO x gas. The high DFF selectivity is ascribed to Cu 2+ cation which can effectively prohibit oxidative C C bond cleavage reaction of HMF and prevent radical reaction of DFF to humins. In addition, the polarity of solvent plays a great role on high selectivity of DFF.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2017
·
IF 3.615
Yueyang Liu,Ming Zhao,Linjuan Cheng,Jianhua Yang,Liping Liu,Jinqu Wang,Dehong Yin,Jinming Lu,Yan Zhang
A facile one-pot method through controlled nucleation and release of reactive nutrient species by using bulk silicon dioxide as the Si source and seeds as liberated nuclei was reported for the fabrication of hierarchical ZSM-5 zeolites . This ZSM-5 aggregation (ZSM-5-B) was hierarchically constructed by many flaky ZSM-5 crystals. High methane conversion, high selectivity of aromatics and excellent anti-coking stability were achieved in the catalytic methane dehydroaromatization reaction (MDA) as a model reaction using the Mo-modified ZSM-5-B catalyst. Structure-properties relevance studies indicated the synergistic integration of the suitable acidity, higher external surface and hierarchical porosity contributed to the largely improved MDA catalytic performance. The work demonstrates a much simpler and more economical route for practical application of hierarchical zeolite.
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ACS Chemical Biology
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2017
·
IF 4.995
Jun Xiong,Xiaona Liu,Qing-Yun Cheng,Shan Xiao,Lai-Xin Xia,Bi-Feng Yuan,Yu-Qi Feng
Toxic heavy metals have been considered to be harmful environmental contaminations. The molecular mechanisms of heavy-metals-induced cytotoxicity and carcinogenicity are still not well elucidated. Previous reports showed exposures to toxic heavy metals can cause a change of DNA cytosine methylation (5-methylcytosine, 5-mC). However, it is still not clear whether heavy metals have effects on the recently identified new epigenetic marks in both DNA and RNA, i.e., 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC). Here, we established a chemical labeling strategy in combination with liquid chromatography–electrospray ionization–mass spectrometry (LC-ESI-MS/MS) analysis for highly sensitive detection of eight modified cytidines in DNA and RNA. The developed method allowed simultaneous detection of all eight modified cytidines with improved detection sensitivities of 128–443-fold. Using this method, we demonstrated that the levels of 5-hmC, 5-foC, and 5-caC significantly decreased in both the DNA and RNA of mouse embryonic stem (ES) cells while exposed to arsenic (As), cadmium (Cd), chromium (Cr), and antimony (Sb). In addition, we found that treatments by heavy metals induced a decrease of the activities of 10–11 translocation (Tet) proteins. Furthermore, we revealed that a content change of metabolites occurring in the tricarboxylic acid cycle may be responsible for the decline of the derivatives of 5-mC. Our study shed light on the epigenetic effects of heavy metals, especially for the induced decline of the derivatives of 5-mC in both DNA and RNA.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2016
·
IF 3.349
Lulu Li,Qinglun Meng,Junjun Wen,Jingui Wang,Gaomei Tu,Chunhui Xu,Fumin Zhang,Yijun Zhong,Weidong Zhu,Qiang Xiao
Hierarchical Fe-ZSM-5 zeolites were directly synthesized from a zeolitic synthesis system in the presence of a silane coupling agent 3-glycidoxypropyltrimethoxysilane (GPTMS). The structure and morphology of the hierarchical Fe-ZSM-5 synthesized with different amount of GPTMS were characterized by XRD , SEM, TEM , and N 2 adsorption-desorption techniques. UV–vis and NH 3 -TPD were used to investigate the state of iron species and acidity, respectively. The steaming activated hierarchical Fe-ZSM-5 were used as catalysts in the direct oxidation of benzene to phenol (BTOP) with N 2 O as oxidant, showing an improved performance in terms of both activity and stability compared to Fe-ZSM-5 synthesized in the absence of GPTMS. A comparison study on the n -butane uptakes in Fe-ZSM-5 zeolites indicated the internal mass-transfer limitations of the hierarchical Fe-ZSM-5 zeolites were significantly improved.
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GREEN CHEMISTRY
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2016
·Vol. 18
·期 13
·3858-3866
·
IF 8.506
Meng-Yuan Chen,Chu-Bai Chen,Bakht Zada,Yao Fu
The hydrogenolysis of C–O and CO in 5-hydroxymethylfurfural for the production of furan biofuel 2,5-dimethylfuran (DMF) is of great importance for biomass refining. However, development of non-noble metal-based catalysts which perform stably for this process is still challenging. Here, perovskite-supported Ni catalysts were used for the hydrogenolysis of 5-hydroxymethylfurfural at 230 °C, with 98.3% yield of DMF being obtained. The effects of reaction conditions such as temperature and pressure were investigated and discussed, and the catalyst could maintain good activity after being used at least 5 times. In order to further explore the reaction mechanism, dynamic experiments at different times were carried out and a possible reaction pathway was proposed. The development of efficient perovskite-supported Ni catalysts verified their great potential in biomass conversion.
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Evidence-based Complementary and Alternative Medicine
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2016
·
IF 1.931
Ke Fang,Hui Dong,Shujun Jiang,Fen Li,Dingkun Wang,Desen Yang,Jing Gong,Wenya Huang,Fuer Lu
To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition.
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ChemCatChem
·
2016
·Vol. 8
·期 21
·3317-3322
·
IF 4.724
Ziyu Liu,Dan Wu,Shu Ren,Xinqing Chen,Minghuang Qiu,Xian Wu,Chengguang Yang,Gaofeng Zeng,Yuhan Sun
Graphical Gasoline from methanol : ZSM-5 crystals with controllable c -axis length were successfully synthesized through a one-pot solvent-free route, with urea as an additive. Catalytic tests for the methanol to gasoline (MTG) conversion showed that the prepared c -axis oriented hierarchical ZSM-5, which allow fast mass transfer, exhibited both 100 % methanol conversion and far longer lifetime (900 h) than those of ZSM-5 with conventional morphology (350 h). ZSM-5 crystals with controllable c -axis length were successfully synthesized through a one-pot solvent-free route, with urea as an additive. X-ray diffraction patterns (XRD) show that the prepared samples exhibit high crystallinity. N 2 adsorption–desorption isotherms and mercury intrusion porosimetry (MIP) analysis together with TEM observations indicate that micro-, meso-, and macropores exist in the obtained samples. Catalytic tests for the methanol to gasoline (MTG) conversion showed that the prepared c -axis oriented hierarchical ZSM-5, which allow fast mass transfer, exhibited both 100 % methanol conversion and far longer lifetime (900 h) than those of ZSM-5 with conventional morphology (350 h) in the MTG reaction. The enhanced MTG performance by the c -axis oriented zeolite under one-pot solvent-free synthesis is of great importance as it is easily scaled-up for industrial applications.
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Energy Technology
·
2016
·Vol. 5
·期 5
·747-755
·
IF 2.557
Tingwei Zhang,Wei Fan,Wenzhi Li,Zhiping Xu,Haosheng Xin,Mingxue Su,Yijuan Lu,Longlong Ma
Sn-β zeolite and PTSA–POM, made from the copolymerization of p -toluenesulfonic acid (PTSA) and paraformaldehyde (POM), were used for the production of 5-(hydroxymethyl)furfural (HMF) from glucose in an environmentally friendly solvent system including γ-valerolactone (GVL) and H 2 O. The effects of reaction temperature, reaction time, solvent, and catalyst-to-reactant ratio on the production of HMF were investigated. The combination of the Brønsted acid and Lewis acid catalysts largely improved the catalytic system and resulted in the production of HMF in 60.1 % yield at 140 °C in 30 min. The presence of water in the solvent had a positive influence on the production of HMF from glucose. The combination of the two catalysts also improved the catalytic performance for the production of HMF from cellulose and corn stalk.
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