NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 45
·期 2
·705-713
·
IF 3.288
Samuthirarajan Senthilkumar,Wei Zhong,Mookan Natarajan,Chunxin Lu,Binyu Xu,Xiaoming Liu
An efficient and green protocol for aerobic oxidation of benzylic alcohols in ethanol using CuI–Y zeolite catalysts assisted by TEMPO (TEMPO = 2,2,6,6-tetramethyl-1-piperidine-N-oxyl) as the radical co-catalyst in the presence of atmospheric air under mild conditions is reported. The CuI–Y zeolite prepared via ion exchange between CuCl and HY zeolite was fully characterized by a variety of spectroscopic techniques including XRD, XPS, SEM, EDX and HRTEM. The incorporation of Cu(I) into the 3D-framework of the zeolite rendered the catalyst with good durability. The results of repetitive runs revealed that in the first three runs, there was hardly a decline in activity and a more substantial decrease in yield was observed afterwards, while the selectivity remained almost unchanged. The loss in activity was attributed to both the formation of CuO and the bleaching of copper into the liquid phase during the catalysis, of which the formation of CuO was believed to be the major contributor since the bleaching loss for each run was negligible (<2%). In this catalytic system, except TEMPO, no other additives were needed, either a base or a ligand, which was essential in some reported catalytic systems for the oxidation of alcohols. The aerobic oxidation proceeded under mild conditions (60 °C, and 18 hours) to quantitatively and selectively convert a wide range of benzylic alcohols to corresponding aldehydes, which shows great potential in developing green and environmentally benign catalysts for aerobic oxidation of alcohols. The system demonstrated excellent tolerance against electron-withdrawing groups on the phenyl ring of the alcohols and showed sensitivity to steric hindrance of the substrates, which is due to the confinement of the pores of the zeolite in which the oxidation occurred. Based on the mechanism reported in the literature for homogenous oxidation, a mechanism was analogously proposed for the aerobic oxidation of benzylic alcohols catalysed by this Cu(I)-containing zeolite catalyst.
研究领域:
化学
·
催化
·
绿色化学
·
材料科学
✓ 已验证
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2019
·
IF 0.486
Liping Zhou,Hao Hu,Yi-Xin Zhang,Qing-Ye Meng,Bing Yu,You-Qing Shen,Hai-Lin Cong
Dendrimers have become effective drug carriers and gene transfection vectors for medical biomaterials. In this experiment, UCNPs (NaGdF4:Tm, Yb@NaGdF4) and three-generation PAMAM dendrimers were prepared firstly; then NaGdF4:Tm, Yb@NaGdF4 was modified by Polyacrylic acid(PAA); PAMAM were grafted to the surface of the modified UCNPs by the reaction between amino groups and carboxyl groups; finally, O-nitrobenzaldehyde was grafted to the surface by Schiff base reaction.The synthesized upconversion materials were coated with PAA and PAMAM, then loaded with O-nitrobenzaldehyde to form spherical nanoparticles. The particle size of prepared nanoparticles is 75 ∼ 80 nm. The dendrimer complex can emit ultraviolet light to regulate the pH gradient of aqueous solution under the excitation of near-infrared light (980 nm), and can be used to kill cancer cells by changing the acidity of tissue cells; secondly, the cavity between dendrimers and dendrimers on the surface of the complex can be used in many fields such as drug delivery and gene transfection; the nanoparticles provide a new method for cancer treatment.
研究领域:
生物医学工程
·
纳米医学
·
肿瘤学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 9
·744
·
IF 4.4
Xin Pan,Yanan Zhu,Yongchang Yang,Qianqian Zhu
The catalytic oxidation of alcohols is an important transformation in the chemical industry. Carbon materials with a large surface area and N doping show great promise as metal-free catalysts for the reaction. In this study, a rich N-containing covalent triazine framework polymerized by cyanuric chloride and p-phenylenediamine was used to synthesize N-doped porous carbon with the assistance of a pore-forming agent—NaCl. First, the mass ratio of the polymer/NaCl was optimized to 1:9. Then, the influence of the pyrolysis temperatures (700–1000 °C) on the materials was studied in detail. It was found that the carbon materials were gradually exfoliated by molten salt at high temperatures. XRD and Raman characterizations showed them with a certain graphitization. The optimal doped carbon CNN-1-9-900 achieved the highest surface area of 199.03 m2g−1with the largest pore volume of 0.29 cm3g−1. Furthermore, it had a high N content of 9.9 at% with the highest relative proportion of pyridinic/graphitic N. Due to the synergistic effect between the surface area and pyridinic/graphitic N, CNN-1-9-900 showed the best performance for benzyl alcohol oxidation with TBHP at moderate conditions, and the process also worked for its derivatives.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 44
·26142-26150
·
IF 3.119
Binyu Xu,Samuthirarajan Senthilkumar,Wei Zhong,Zhongquan Shen,Chunxin Lu,Xiaoming Liu
In this work, core–shell Fe3O4@Cu2O and Fe3O4@Cu2O–Cu nanomaterials for aerobic oxidation of benzylic alcohols are reported with 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and N-methylimidazole (NMI) as the co-catalysts. To anchor Cu2O nanoparticles around the magnetic particles under solvothermal conditions, the magnetic material Fe3O4 was modified by grafting a layer of L-lysine (L-Lys) to introduce –NH2 groups at the surface of the magnetic particles. With amine groups as the anchor, Cu(NO3)2 was used to co-precipitate the desired Cu2O by using ethylene glycol as the reducing agent. Prolonging the reaction time would lead to over-reduced forms of the magnetic materials in the presence of copper, Fe3O4@Cu2O–Cu. The nanomaterials and its precursors were fully characterized by a variety of spectroscopic techniques. In combination with both TEMPO and NMI, these materials showed excellent catalytic activities in aerobic oxidation of benzylic alcohols under ambient conditions. For most of the benzylic alcohols, the conversion into aldehydes was nearly quantitative with aldehydes as the sole product. The materials were recyclable and robust. Up to 7 repeat runs, its activity dropped less than 10%. The over-reduced materials, Fe3O4@Cu2O–Cu, exhibited slightly better performance in durability. The magnetic properties allowed easy separation after reaction by simply applying an external magnet.
研究领域:
材料科学
·
催化
·
化学工程
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULES
·
2014
·
IF 5.927
Jun Peng,Renfeng Dong,Biye Ren,Xueyi Chang,Zhen Tong
Novel dendron hydrophobically modified ethoxylated urethanes (DHEUR) with almost the same molecular weights, molecular weight distributions, and identical hydrophilic portion but different terminal hydrophobic group numbers were prepared by using Percec-type alkyl substituted benzyl alcohol dendrons as new end-cappers. These DHEUR polymers in solution possess interesting associative and rheological behavior. For DHEUR-1 with 4-mono(decyloxy)benzyl alcohol (2), the solutions are dominantly composed of the isolated and separated micelles and exhibit Newtonian behavior in a wide shear rate range accompanied by shear thinning at high shear rate region. DHEUR-2 with 3,5-di(decyloxy)benzyl alcohol (4) in solutions form a relatively more complete network through dominant micellar junctions and process a relatively higher solution viscosity and similar solution viscosity behavior to DHEUR-1. However, shear thinning behavior shifts to a lower shear rate region due to a relatively longer relaxation time. Interestingly, the solutions of DHEUR-3 with 3,4,5-tri(decyloxy)benzyl alcohol (6) have developed a complete physical network and show pronounced shear thinning behavior over the whole shear rate range. The oscillatory measurements further confirm that a gradually developing associative network leads to their different solution rheological behavior, i.e., viscous fluid (DHEUR-1), viscoelastic fluid (DHEUR-2), and elastic body (DHEUR-3) with increasing the hydrophobic tail number of dendrons. Furthermore, the rheological activation energy of these DHEUR polymers increases with the increase of terminal hydrophobic group numbers, indicating that DHEUR polymers with more hydrophobic tail chains need more energy potential barrier for the disengagement of hydrophobes from micelles due to stronger association strength. In general, the results demonstrate that the terminal hydrophobic tail number of dendrons plays a key role in determining the associative and rheological behavior of DHEUR in solutions. This work opens a new perspective for more efficient thickeners and also promises the potential of these DHEUR polymers in waterborne coating, cosmetics, dyestuff, medicines, and so on for the first time.
研究领域:
材料科学
·
化学工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MRS Communications
·
2016
·Vol. 6
·期 1
·31-40
·
IF 1.797
Liu Yongkun,Jiang Guohua,Li Lei,Chen Hua,Huang Qin,Jiang Tengteng,Du Xiangxiang
In this work, we developed a convenient way to immobilize silver nanoparticles on the aminated polyacrylonitrile (PAN) nanofibrous mats by combing the electrospinning technology from complex-containing polymer solution, amination of PAN nanofibrous and electroless plating technique. The resultant composite nanaofibrous mats had been characterized by scanning electron microscopy, energy-dispersive spectrometer, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectra analysis. The catalytic activity and stability of these resultant composite nanofibrous mats for the catalytic reactions, including reduction of 4-nitrophenol to form 4-aminophenol, and selective oxidation of benzyl alcohol, were investigated. The resultant nanofibrous mats exhibited high-efficiency, convenient separation, recovery, and cyclic utilization properties.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 8
·4302-4309
·
IF 11.9
Menghan Yu,Nan Wang,Kuo Lin,Dongxue Song,Jie Chen,Teng Liang,Jianhui Sun,Kai Pan,Honggang Fu
Photocatalytic selective oxidation of benzyl alcohol into benzaldehyde at normal temperature and pressure is one of the important topics in the catalysis field. Here, a lead-free double perovskite Cs2AgBiBr6 nanocrystal/mesoporous black TiO2 composite was prepared by a vacuum-assisted method, and then it was applied for photocatalytic selective oxidation. The photocatalytic oxidation of benzyl alcohol to benzaldehyde was found to occur with 75% conversion and 99% selectivity with the Cs2AgBiBr6 nanocrystal/black TiO2 composite, which were better than those of single Cs2AgBiBr6 nanocrystals and black TiO2, respectively. This was due to the formation of a Z-type heterogeneous structure between Cs2AgBiBr6 nanocrystals and black TiO2, which effectively promoted the separation and transfer of electrons and holes, ultimately leading to excellent photocatalytic activity. During the whole catalytic process, carbon-centered radicals were the key intermediates for the dehydrogenation of benzyl alcohol. This work may provide some practical suggestions for the fabrication of benzyl alcohol selective oxidation photocatalysts.
研究领域:
催化
·
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy and Sustainability Research
·
2023
·Vol. 4
·期 12
·2300122
·
IF 5.8
Jian Lei,Hongyuan Yang,Ziliang Chen,Sugang Meng,Nan Zhou,Yang Yang,Prashanth W. Menezes
CO 2 reduction (CO 2 RR) with selective benzyl alcohol (BA) oxidation in a single photoredox reaction can simultaneously utilize photogenerated electrons and holes to realize efficient production of fuels and value-added chemicals. Herein, a unique 2D/1D ZnIn 2 S 4 /In 2 O 3 (ZIS/In 2 O 3 ) heterostructure is developed displaying outstanding performance for photoredox catalysis. As is unequivocally illustrated by various advanced ex situ/in situ characterizations and theoretic calculations, the notable catalytic performances originate from the built-in interfacial electric field within the ZIS/In 2 O 3 heterostructure, which strongly ameliorates the separation and transport of charge carriers. Remarkably, the catalytic activity can further be boosted after coupling the additional thermal treatments, and the product selectivity is highly temperature dependent. Thereby, the precise formation of targeted products, which can serve as valuable industrial products and fuels can be controlled by changing the reaction temperatures, including obtaining the syngas with different H 2 /CO ratios from CO 2 reduction, as well as benzaldehyde, hydrogenated benzoin, and dibenzyl ether (never reported for BA during photocatalysis) from the BA conversion. This study offers a constructive and inspiring contribution to reasonably developing photoredox catalysts, which can fully utilize photogenerated electrons and holes, as well as demonstrate how to controllably yield the targeted products by coupling thermo- and photoredox catalysis.
研究领域:
催化
·
材料科学
·
环境化学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
Solar RRL
·
2021
·Vol. 5
·期 12
·2100559
·
IF 8.582
Hong-Hong Zhang,Zi-Chun Zhou,Yu-Jie Dong,Li Zhang,Hong-Yan Chen,Dai-Bin Kuang
Utilizing halide perovskites for photocatalytic aromatic C( sp 3 ) H bond activation remains a great challenge due to the serious recombination of photogenerated charge carriers and slow reaction dynamics of the materials themselves. Herein, a lead-free perovskite-based hybrid of Cs 3 Sb 2 Br 9 /g-C 3 N 4 nanosheet is constructed and applied for photocatalytic aromatic C( sp 3 ) H bond activation, which shows enhanced photocatalytic performance. By introducing ultrathin g-C 3 N 4 nanosheets as the heterogeneous nucleation sites, size-reduced and well-dispersed Cs 3 Sb 2 Br 9 nanocrystals can be obtained. The as-formed close contact and high-quality heterointerface between Cs 3 Sb 2 Br 9 and g-C 3 N 4 provides pathways for fast charge transfer which is beneficial to improve the separation efficiency of photogenerated electron−hole pairs. Under visible light irradiation, the Cs 3 Sb 2 Br 9 /g-C 3 N 4 hybrid photocatalyst can effectively oxidize toluene toward benzaldehyde and benzyl alcohol with a total conversion rate of 8346.8 μmol g −1 h −1 , which is 26.6- and 6.0-fold that of pure g-C 3 N 4 and Cs 3 Sb 2 Br 9 , respectively. This work demonstrates the potential of all-inorganic lead-free halide perovskite-based heterostructures for photocatalytic organic reactions.
研究领域:
材料科学
·
化学
·
光催化
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
TETRAHEDRON
·
2017
·
IF 2.651
Qiujie Tang,Ping Xie,Jin Wang,Jiajun Lin,Chunlai Feng,Charles U. Pittman,Aihua Zhou
Two cascade coupling reactions were developed between N -alkyl(aryl)- N -methacryloyl benzamides and readily available benzyl alcohols or sodium benzenesulfinates . Through a radical cyclization strategy, these one-pot sequential reactions provided two simple and efficient approaches to the synthesis of a variety of isoquinoline-1,3(2H,4H)-dione derivatives in high yields with a broad substrate scope. These compounds are valuable molecules in drug discovery .
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
Experimental and Therapeutic Medicine
·
2021
·Vol. 21
·期 3
·1-1
·
IF 2.447
Qing Lin,Weili Wang,Liping Yang,Xiaohua Duan
Damage to the blood‑brain barrier (BBB) during the process of cerebral ischemic injury is a key factor that affects the treatment of this condition. The present study aimed to assess the potential effects of 4‑methoxybenzyl alcohol (4‑MA) on brain microvascular endothelial cells (bEnd.3) against oxygen‑glucose deprivation/reperfusion (OGD/Rep) using an in vitro model that mimics in vivo ischemia/reperfusion injury. In addition, the present study aimed to explore whether this underlying mechanism was associated with the inhibition of pro‑inflammatory factors and the activation status of the PI3K/Akt signaling pathway. bEnd.3 cells were subjected to OGD/Rep‑induced injury before being treated with 4‑MA, following which cell viability, lactate dehydrogenase (LDH) release and levels of nitric oxidase (NO) were detected by colorimetry, pro‑inflammatory factors including tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑1β and IL‑6, were detected by ELISA. The expression levels of occluding and claudin‑5were evaluated by immunofluorescence staining. The expression levels of AKT, phosphorylated (p)‑Akt, endothelial nitric oxide synthase (eNOS) and p‑eNOS were also measured by western blot analysis. After bEnd.3 cells were subjected to OGD/Rep‑induced injury, cell viability and NO levels were significantly decreased, whilst LDH leakage and inflammatory factor (TNF‑α, IL‑1β and IL‑6) levels were significantly increased. Treatment with 4‑MA significantly ameliorated cell viability, LDH release and the levels of NO and pro‑inflammatory factors TNF‑α, IL‑1β and IL‑6 as a result of OGD/Rep. Furthermore, treatment with 4‑MA upregulated the expression of occludin, claudin‑5, Akt and eNOS, in addition to increasing eNOS and AKT phosphorylation in bEnd.3 cells. These results suggest that 4‑MA can alleviate OGD/Rep‑induced injury in bEnd.3 cells by inhibiting inflammation and by activating the PI3K/AKT signaling pathway as a possible mechanism. Therefore, 4‑MA can serve as a potential candidate for treating OGD/Rep‑induced injury.
研究领域:
神经科学
·
药理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2019
·
IF 5.997
Na Zhao,Chuanli Ren,Yong Shen,Shaofeng Liu,Zhibo Li
Degradable long-chain aliphatic polyesters are promising alternatives to polyolefins. The ring-opening polymerization (ROP) of ω-pentadecalactone (PDL) enables the synthesis of aliphatic polyesters with melting temperature close to low-density polyethylene (LDPE). However, this ROP reaction is of great challenge because of low ring strain of the PDL monomer. The occurrence of intra- and intermolecular transesterification reactions during ROP made it difficult to prepare well-defined block copolyesters for advanced properties. In this context, cyclic trimeric phosphazene base (CTPB) in combination with benzyl alcohol (BnOH) was proved to be an efficient initiator system for ROP of PDL, showing an excellent polymerization rate (TOF up to 600 h–1) at 80 °C. Well-defined diblock copolyesters, i.e., PPDL-b-PLLA, can be easily synthesized by sequential addition of PDL and l-lactide (L-LA). In contrast, sequential addition of PDL and ε-caprolactone (CL) or δ-valerolactone (VL) only led to the random copolyesters under the same conditions. On the other hand, CTPB is an inherent tribasic superbase and can be partially neutralized to decrease its basicity for better control over active lactones such as CL and VL. Hence, we introduced 0.33–1.0 equiv of benzoic acid (PhCOOH) relative to CTPB and demonstrated that it can diminish the transesterification during ROP of CL or VL. Based on this strategy, PPDL-b-PCL or PPDL-b-PVL diblock copolyesters were successfully prepared by sequential addition of monomers of CL or VL after ROP of PDL. The block copolyester structures were confirmed by the 13C NMR spectroscopy and DSC characterizations.
研究领域:
高分子化学
·
材料科学
✓ 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）