Integrating TEMPO or Its Analogues with Visible Light Photocatalysis Chem. Asian J. (IF 4.083) Pub Date : 2018-01-16 Xianjun Lang, Jincai Zhao
Visible light has risen to be a very important facilitator for selective radical reactions enabled by well-cognized photocatalysts. The renaissance of visible light photocatalysis on this matter partly relies on integrating it with other area of catalysis. In parallel, TEMPO, a quintessential persistent radical, has a wide range of uses due to its exceptional redox behavior, giving rise to its latest prominence in catalysis. Therefore, integrating the catalysis of TEMPO with photocatalysis to carry out visible light-induced selective reactions becomes very convenient marriage of merits. In this context, the integration of different types of photocatalysts including metal complexes, metal-free organic dyes and semiconductors with TEMPO for outstanding organic transformations will be summarized separately. To further expand the catalytic repertoire, the integration of TEMPOH analogues such as NHPI (N-hydroxyphthalimide) or NHS (N-hydroxysuccinimide) with photocatalysis will also be discussed in different sections. Hopefully, these advances could pave the way for more breakthroughs by integrating TEMPO and its analogues with photocatalysis, leading to a valuable blueprint for visible light-induced selective organic transformations.
Synthesis of Functionalized (η5-Indenyl)rhodium(III) Complexes and Their Application to C-H Bond Functionalization Chem. Asian J. (IF 4.083) Pub Date : 2018-01-16 Jyunichi Terasawa, Yu Shibata, Yuki Kimura, Ken Tanaka
It has been established that reductive complexation of functionalized benzofulvenes, which are readily prepared from commercially available indene and 2-methylindene, with RhCl3 in ethanol affords the corresponding indenyl-rhodium(III) dichlorides bearing substituents at the 1- (H or CO2Et), 2- (H or Me), and 3- [CH2Ph or CH2(2-MeOC6H4)] positions. The thus obtained indenyl-rhodium(III) complexes bearing one ethoxycarbonyl group showed higher thermal stability and regioselectivity than our previously reported CpERhIII complex toward the oxidative [3+2] annulation of acetanilides with internal alkynes.
Prussian Blue Derived FeP Nanoparticles in Porous Graphene Aerogel as Efficient Electrocatalysts for Hydrogen Evolution Reaction Chem. Asian J. (IF 4.083) Pub Date : 2018-01-16 Narendra Kumar Alam Venugopal, Shuli Yin, Yinghao Li, Hairong Xue, You Xu, Xiaonian Li, Hongjing Wang, Liang Wang
Tailoring of new hydrogen evolution reaction (HER) electrocatalyst with earth abundant elements is important for large scale water splitting and hydrogen production. In this work, we present a simple synthetic method for incorporating iron phosphide (FeP) particles into three-dimensional (3D) porous graphene aerogel (GA) structure. The FeP formed in porous 3D GA (FeP/GA) is derived from electroactive Fe hexacyanoferrate (FeHCF). The advantage of incorporating FeP, in the porous 3D graphene network enables high accessibility for HER. As synthesized FeP/GA catalyst shows good electrocatalytic activity for HER in both acidic and alkaline solutions. The developed method can be useful for synthesizing metal hexacyanoferrate derived mono/bimetal phosphide catalyst in porous 3D graphene aerogels.
Block Copolymer Self-Assembly in Solution—Quo Vadis? Chem. Asian J. (IF 4.083) Pub Date : 2018-01-16 Johannes C. Brendel, Felix H. Schacher
Pomegranate-Structured Silica/Sulfur Composite Cathodes for High Performance Lithium-Sulfur Batteries Chem. Asian J. (IF 4.083) Pub Date : 2018-01-14 Soojin Park, Sinho Choi, Dawei Su, Myoungsoo Shin, Guoxiu Wang
Porous materials have many structural advantages for energy storage and conversion devices such as rechargeable batteries, supercapacitors, and fuel cells. When applied as a host material in lithium-sulfur batteries, porous silica materials with a pomegranate-like architecture can not only act as a buffer matrix for accommodating a large volume change of sulfur, but also suppress the polysulfide shuttle effect. The porous silica/sulfur composite cathodes exhibit excellent electrochemical performances including a high specific capacity of 1450 mA h g-1, a reversible capacity of 82.9 % after 100 cycles at a rate of C/2 (1 C = 1672 mA g-1) and an extended cyclability over 300 cycles at 1 C-rate. Furthermore, the high polysulfide adsorption property of porous silica has been proven by ex-situ analyses, showing a relationship between the surface area of silica and polysulfide adsorption ability. In particular, the modified porous silica/sulfur composite cathode, which is treated by a deep-lithiation process in the first discharge step, exhibits a highly reversible capacity of 94.5 % at 1C-rate after 300 cycles owing to a formation of lithiated-silica frames and stable solid-electrolyte-interphase layers
Solvent Impedes CO2 Cycloaddition on Metal-Organic Frameworks Chem. Asian J. (IF 4.083) Pub Date : 2018-01-13 Dan Shao, Jinbiao Shi, Jianling Zhang, Xiuniang Tan, Tian Luo, Xiuyan Cheng, Bingxing Zhang, Buxing Han
The catalytic performance of metal-organic frameworks (MOFs) for the synthesis of cyclic carbonate from carbon dioxide and epoxides has been explored in solvent and solvent-free conditions, respectively. It was found that MOF catalysts have significantly improved catalytic activities in solvent-free CO2 cycloaddition reactions than those in solvent. The mechanism was discussed from the competition of solvent with substrate to adhere MOF catalysts during reaction process.
In Situ Growth of MnO2 Nanosheets on N-Doped Carbon Nanotubes Derived from Polypyrrole Tubes for Supercapacitors Chem. Asian J. (IF 4.083) Pub Date : 2018-01-13 Xu Ou, Qi Li, Dan Xu, Jiangna Guo, Feng Yan
Nitrogen-doped porous carbon nanotubes@MnO2 (N-CNTs@MnO2) nanocomposites are prepared through the in situ growth of MnO2 nanosheets on N-CNTs derived from polypyrrole nanotubes (PNTs). Benefiting from the synergistic effects between N-CNTs (high conductivity and N doping level) and MnO2 nanosheets (high theoretical capacity), the as-prepared N-CNTs@MnO2-800 nanocomposites show a specific capacitance of 219 F g-1 at a current density of 1.0 A g-1, which is higher than that of pure MnO2 nanosheets (128 F g-1) and PNTs (42 F g-1) in 0.5 M Na2SO4 solution. Meanwhile, the capacitance retention of 86.8 % (after 1000 cycles at 10 A g-1) indicates an excellent electrochemical performance of N-CNTs@MnO2 prepared in this work.
Syntheses and properties of meso-substituted porphyrin mesogens with triazole linkages and peripheral alkyl chains Chem. Asian J. (IF 4.083) Pub Date : 2018-01-12 Ruilin Zhang, Hongfei Gao, Yanming Ren, Yulong Xiao, Jinliang Hu, Xiaohong Cheng
Novel discotic mesogens P/n-M (n = 12, 16, 18, M = 2H, Zn and Cu) bearing a porphyrin core, triazole linkages and peripheral 3,4,5-trialkoxybenzyl units have been synthesized by "click chemistry" approach. The thermal behavior, photophysical properties and morphologies of these compounds were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), UV and PL spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These compounds can self-assemble into hexagonal columnar phases in their pure states and form organogels in 1,4-dioxane with unusually flower-like sphere morphology. The supramolecular complexes of P/18-Zn with C70 or 4,7-di-4-pydriyl-2,1,3-benzothadiazole can display hexagonal columnar phases too. Additionally, zinc porphyrin compounds P/n-Zn show binding selectivity to Cu2+ among a series of cations in THF-H2O solution.
Copper-Catalyzed Oxidative Reaction of β-Keto Sulfones with Alcohols via C−S Bond Cleavage: Reaction Development and Mechanism Study Chem. Asian J. (IF 4.083) Pub Date : 2018-01-12 Bingnan Du, Wenmin Wang, Yang Wang, Zheng-Hang Qi, Jiaqi Tian, Jie Zhou, Xiaochen Wang, Jianlin Han, Jing Ma, Yi Pan
A Cu-catalyzed cascade oxidative radical process of β-keto sulfones with alcohols has been achieved by using oxygen as an oxidant. In this reaction, β-keto sulfones were converted into sulfinate esters under the oxidative conditions via cleavage of C-S bond. Experimental and computational studies demonstrate that a new pathway is involved in this reaction, which proceeds through the formation of the key four-coordinated Cu(II) intermediate, O−O bond homolysis induced C−S bond cleavage and Cu-catalyzed esterification to form the final products. This reaction provides a new strategy to sulfonate esters and enriches the research contend of the C−S bond cleavage and transformations.
Synthesis of hollow mesoporous TiO2 microspheres with single and double Au nanoparticles layers for enhanced visible light photocatalysis Chem. Asian J. (IF 4.083) Pub Date : 2018-01-12 Zia Ur Rahman, Ning Wei, Yange Feng, Xiaolong Zhang, Daoai Wang
A facile method was used to prepare hollow mesoporous TiO2 and Au@TiO2 spheres using polystyrene (PS) templates. Au nanoparticles (NPs) were simultaneously synthesized and attached on the surface of PS spheres by reducing AuCl4- ions using sodium citrate which resulted in the uniform deposition of Au NPs. The outer coating of titania via sol-gel produced PS@Au@TiO2 core-shell spheres. Removing the templates from these core-shell spheres through calcination produced hollow mesoporous and crystalline Au@TiO2 spheres with Au NPs inside the TiO2 shell in a single step. Anatase spheres with double Au NPs layers, one inside and another outside of TiO2 shell, were also prepared. Different characterization techniques indicated the hollow mesoporous and crystalline morphology of the prepared spheres with Au NPs. Hollow anatase spheres with Au NPs indicated enhanced harvesting of visible light and therefore demonstrated efficient catalytic activity toward the degradation of organic dyes under the irradiation of visible light as compared to bare TiO2 spheres.
Aerobic photooxidative synthesis of β-alkoxy mono-hydroperoxides using an organo photoredox catalyst controlled by a base Chem. Asian J. (IF 4.083) Pub Date : 2018-01-12 Yuya Asano, Yoshitomo Nagasawa, Eiji Yamaguchi, Akichika Itoh
In the proposed study, transition-metal-free synthesis of β-alkoxy monohydroperoxides via aerobic photooxidation using an acridinium photocatalyst was developed. This method enables the synthesis of some novel hydroperoxides. The peroxide source is molecular oxygen, which is cost-effective and is atomically efficient. Magnesium oxide plays an important role as a base in the catalytic system.
Constructing ordered three-dimensional channels of TiO2 for enhanced visible-light photo-catalytic performance of CO2 conversion induced by Au nanoparticles Chem. Asian J. (IF 4.083) Pub Date : 2018-01-11 Hairong Xue, Tao Wang, Hao Gong, Hu Guo, Xiaoli Fan, Bin Gao, Yaya Feng, Xianguang Meng, Xianli Huang, Jianping He
As a typical photo-catalyst for CO2 reduction, the practical application of TiO2 still suffers from low photo-catalytic efficiency and limited visible light absorption. Here, a novel Au-nanoparticle (NP)-decorated ordered mesoporous TiO2 (OMT) composite (OMT-Au) was successfully fabricated, in which Au NPs uniformly disperse on the OMT. Due to the surface plasmon resonance (SPR) effect derived from the excited Au NPs, TiO2 possesses high photo-catalytic performance for CO2 reduction under visible light. The ordered mesoporous exhibits the superiority of material and structure. This ordered mesoporous structure of TiO2 with a high surface area offers more catalytic activity sites. More importantly, the three-dimensional transport channels ensures smooth flow of gas molecules, high-efficient adsorption ability of CO2, and the fast and steady transmission of hot electrons excitation on Au NPs, thus leading to further improving photo-catalytic performance. These results highlight the possibility of improving visible light photo-catalysis for CO2 reduction by constructing OMT-based Au-SPR-induced photo-catalysts.
Imine-based architectures at surfaces and interfaces: from self-assembly to dynamic covalent chemistry in 2D Chem. Asian J. (IF 4.083) Pub Date : 2018-01-11 Iwona Janica, Violetta Patroniak, Paolo Samorì, Artur Ciesielski
During the last two decades dynamic covalent chemistry (DCC) has emerged as an efficient and versatile strategy for the design and synthesis of complex molecular systems in solution. While early examples of supramolecularly assisted covalent synthesis at surfaces relied strongly on kinetically controlled reactions for post-assembly covalent modification, the DCC method takes advantage of the reversible nature of bond formation and allows the generation of the new covalently bonded structures under thermodynamic control. These structurally complex architectures obtained via DCC protocols offer a wealth of solutions and opportunities towards the generation of new complex materials holding sophisticated properties. In this Focus Review we focus on the formation of covalently bonded imine-based discrete nanostructures, as well as one-dimensional (1D) and two-dimensional (2D) covalent organic frameworks (COFs) physisorbed on solid substrates under various experimental conditions, e.g. under ultra-high vacuum (UHV) or at the solid/liquid interface. Scanning tunneling microscopy (STM) is used to gain insight, with a sub-nanometer resolution, into the structure and properties of those complex nanopatterns.
Alkylation-, Heating-, and Doping-Induced Emission Enhancement of a Polyaromatic Tube in the Solid State Chem. Asian J. (IF 4.083) Pub Date : 2018-01-11 Kiyonori Kuroda, Masafumi Otsuki, Kohei Yazaki, Yoshihisa Sei, Munetaka Akita, Michito Yoshizawa
A polyaromatic tube with a subnanometer-sized cavity was efficiently prepared on a gram-scale through the stereo-controlled cyclotrimerization of a diphenylanthracene derivative as a key step. The facile exterior alkylation of the polyaromatic framework leads to a moderately fluorescent tube (R = -OC10H21; ΦF = 20%) in the solid state. The emission intensity of the solid-state alkyl-substituted tube is remarkably enhanced upon heating (up to 1.6 times, ΦF = 31%) as well as doping with fluorescent dyes (up to 4.2 times, ΦF = 83%) through efficient energy transfer.
Cobalt-Doped Perovskite-type Oxide LaMnO3 as Bifunctional Oxygen Catalysts for Hybrid Lithium-Oxygen Batteries Chem. Asian J. (IF 4.083) Pub Date : 2018-01-10 Xiao Liu, Hao Gong, Tao Wang, Hu Guo, Li Song, Wei Xia, Bin Gao, Zhongyi Jiang, Linfei Feng, Jianping He
Perovskite-type oxides based on alkaline-earth containing lanthanum manganate are the promising catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline electrolyte. The perovskite-type LaMnO3 shows excellent ORR performance but poor OER activity. In order to improve OER performance of LaMnO3, the element Co is doped into the perovskite-type LaMnO3 via a sol-gel method with following calcination process. To assess electrocatalytic activities for ORR and OER, a series of prepared LaMn1-xCoxO3 (x = 0, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5) perovskite oxides were synthesized. The results indicate that the amount of doped Co has a significant effect on the catalytic performance of LaMn1-xCoxO3. As researched, when x = 0.3, LaMn0.7Co0.3O3 not only shows a tolerable electrocatalytic activity for ORR, but also exhibits a great improvement (> 200 mV) on the catalytic activity for OER, indicating the doping of Co is an effective approach to improve the OER performance of LaMnO3. Furthermore, the results demonstrate that the LaMn0.7Co0.3O3 is a promising bifunctional catalyst with cost-effective, applied and high-performance for ORR and OER in the hybrid Li-O2 batteries.
Highly Luminescent and Water-Soluble Two-Dimensional Supramolecular Organic Framework: All Organic Photosensitizer Template for Visible Light Driven Hydrogen Evolution from Water Chem. Asian J. (IF 4.083) Pub Date : 2018-01-10 Hyun-Jun Lee, Hyeong-Ju Kim, Eung-Chang Lee, Jaekwan Kim, Soo Young Park
A highly fluorescent (ΦF = 0.60) and water-soluble two-dimensional (2D) honeycomb-shaped supramolecular organic framework (SOF) was successfully synthesized in pure aqueous solution via self-assembly of novel cyanostilbene-functionalized trilateral guest molecules and cucurbituril hosts. Size of this fluorescent 2D SOF was over 500 nm in diameter, 1.7 nm in thickness, and 3.9 nm in the honeycomb pore diameter. This 2D SOF showed a promising potential as a new all-organic photosensitizer template for photocatalytic H₂ evolution from pure water.
Synthesis of Metallic Nanoparticles Using Closed-Shell Structures as Templates Chem. Asian J. (IF 4.083) Pub Date : 2018-01-10 Li Qiu, Ryan McCaffrey, Wei Zhang
Transformations in Chemically Responsive Copper-Calixarene Architectures Chem. Asian J. (IF 4.083) Pub Date : 2018-01-09 Edmundo Percástegui, Carlos Reyes-Mata, Marcos Flores-Alamo, Beatriz Quiroz-García, Ernesto Rivera, Ivan Castillo
Self-assembly of bis-picolyl-appended calixarene (L) with Cu(I) or Cu(II) salts resulted in a collection of multinuclear architectures capable of expressing structural reconfigurations in response to various chemical stimuli: addition of copper salt, solvents, or oxidation. Coordination of L to CuX (X = Br, I) selectively yielded dinuclear macrocycles Cu(I)₂L₂Br₂ (1) and Cu(I)₂L₂I₂ (3) that were transformed into tetranuclear assemblies Cu(I)₄L₂Br₄ (2) and Cu(I)₄L₂I₄ (4) upon further addition of CuX. These supramolecules persist as robust and discrete entities in solution that display red emission; notably, 4 exhibits luminescence thermochromism. Assembly of L with CuCl₂ produced macrocycle Cu(II)₂L₂Cl₄ (5), which crystallised as cage [Cu(II)₂L₄(μ-Cl)]³+ (6) in the presence of MeOH. Two chemical signals -introduction of CuCl₂ and addition of CH₃CN- regenerated macrocycle 5. Coordination of L with Cu(OTf) yielded macrocycle Cu(I)₂L₂(OTf)₂ (7) that also crystallised as cage 6 upon oxidation in CHCl₃.
Formation of fluorinated amido esters through unexpected C3-C4 bond fission in 4-trifluoromethyl-3-oxo-β-lactams Chem. Asian J. (IF 4.083) Pub Date : 2018-01-09 Hang Dao Thi, Hannelore Goossens, Dietmar Hertsen, Valerie Otte, Tuyen Van Nguyen, Veronique Van Speybroeck, Matthias D'hooghe
4-Trifluoromethyl-3-oxo-β-lactams were unexpectedly transformed into 2-[(2,2-difluorovinyl)amino]-2-oxoacetates as major products, accompanied by minor amounts of 2-oxo-2-[(2,2,2-trifluoroethyl)amino]acetates, upon treatment with alkyl halides and triethylamine in DMSO. This peculiar C3-C4 bond fission reactivity was investigated in-depth, from both an experimental and a computational point of view, in order to shed light on the underlying reaction mechanism.
In situ generated ruthenium catalytic systems bearing diverse N-heterocyclic carbene precursors for the atom-economic amide synthesis from alcohols and amines Chem. Asian J. (IF 4.083) Pub Date : 2018-01-09 Hua Cheng, Mao-Qian Xiong, Chuan-Xiang Cheng, Hua-Jing Wang, Qiang Lu, Hong-Fu Liu, Fu-Bin Yao, Francis Verpoort, Cheng Chen
The transition-metal-catalyzed direct amide synthesis from alcohols and amines has been demonstrated as a highly environmental-benign and atom-economic process. Among various catalytic systems, in situ generated N-heterocyclic carbene (NHC)-based ruthenium (Ru) halide catalytic systems have been testified to be active for this attractive transformation. However, these existing catalytic systems usually required an additional ligand to achieve satisfactory results. In this work, through extensive screening from a diverse variety of NHC precursors, we discovered an active in situ catalytic system for the efficient amide synthesis without any additional ligand. Notably, this catalytic system is insensitive to the electronic effects of the substrates, and various electron-deficient substrates, which were not highly reactive with our previous catalytic systems, could be employed to efficiently afford the corresponding amides. Furthermore, mechanistic investigations were performed to demonstrate the rational for the high activity of the optimized catalytic system. The NMR scale reactions indicated that the rapid formation of a Ru hydride intermediate (a peak at -7.8 ppm from 1H NMR) after the addition of the alcohol substrate should be a pivotal factor for manifesting the high catalytic activity. Besides, HR-MS analysis demonstrated the possible structures of the in situ generated catalytic system.
Visible-Light-Promoted Synthesis of 1,4-Dicarbonyl Compounds via Conjugate Addition of Aroyl Chlorides Chem. Asian J. (IF 4.083) Pub Date : 2018-01-08 Chao-Ming Wang, Dan Song, Peng-Ju Xia, Jing Wang, Hao-Yue Xiang, Hua Yang
A facile visible-light photocatalytic conjugate addition to prepare 1,4-dicarbonyl compounds has been developed by employing readily available aroyl chlorides as aryl radical sources. This operationally simple method shows broad scope with regard to both aroyl chlorides and Michael acceptor. As a result, a variety of 1,4-diketones were efficiently synthesized in moderate to good yields.
Carbon Dots: Bottom-Up Syntheses, Properties, and Light-Harvesting Applications Chem. Asian J. (IF 4.083) Pub Date : 2018-01-08 Yuri Choi, Yeongkyu Choi, Oh-Hoon Kwon, Byeong-Su Kim
The development of cost-effective and environmentally friendly photocatalysts and photosensitizers has received tremendous attention because of their potential utilization in solar harvesting applications. In this respect, carbon dots (CDs) prepared by bottom-up methods have been considered to be promising light-harvesting materials. Through preparation from various molecular precursors and synthetic methods, CDs exhibit excellent optical and charge transfer properties. Furthermore, their photophysical properties can be readily optimized and enhanced by doping, functionalization, and post-synthetic treatment. In this review, we summarize the recent progress regarding CDs synthesized using bottom-up approaches that exhibit strong light absorption and unique electron donor/acceptor capabilities for light-harvesting applications. We anticipate that this review will provide new insights into novel types of photosensitizers and photocatalysts for a wide range of applications.
Hydrogen-doping into MoO3 supports toward modulated metal-support interactions and efficient furfural hydrogenation on iridium nanocatalysts Chem. Asian J. (IF 4.083) Pub Date : 2018-01-05 Lifang Xie, Ting Chen, Hang Cheong Chan, Yijin Shu, Qingsheng Gao
As promising supports, reducible metal oxides afford strong metal-support interactions to achieve efficient catalysis, relying on their band states and surface stoichiometry. Herein, in-situ and controlled hydrogen doping (H-doping) via H2 spillover is employed to engineer the metal-support interactions in hydrogenated MoOx supported Ir (Ir/H-MoOx) catalysts, and thus promote furfural hydrogenation to furfuryl alcohol. Via facilely varying reduction temperature, the resulting H-doping in a controlled manner tailors low-valence Mo species (Mo5+ and Mo4+) on H-MoOx supports, and thus charge-redistribution on Ir and H-MoOx interfaces. This further leads to obvious difference in H2 chemisorption on Ir, showing the promise for catalytic hydrogenation. As expected, the optimal Ir/H-MoOx with controlled H-doping affords high activity (TOF: 4.62 min-1) and selectivity (> 99%) in furfural hydrogenation at a mild condition (T = 30 oC, PH2 = 2 MPa), performing among the best of current catalysts.
Large-scalable Preparation of Photochromic Composite Foils with Excellent Reversibility for Light Printing Chem. Asian J. (IF 4.083) Pub Date : 2018-01-05 Yijie Zhou, Aibin Huang, Shidong Ji, Huaijuan Zhou, Ping Jin, Rong Li
Photochromic inks for repeatable light printing media have attracted increasing attention owing to the fact that it may be widely applied to reduce the consumption of papers and plastics for environmental conservation. Therefore, it is of practical significance to develop convenient photochromic inks at a low cost in a large scale. In this study, a simple one-step hydrothermal way was employed to prepare tungsten trioxide (WO3) nanoparticles which was further used to make photochromic inks and transparent photochromic films. The obtained transparent photochromic film could rapidly respond to UV light within tens of seconds, return to its initial state corresponding to different recovering time at each temperature and meanwhile exhibit good reversible coloration-bleaching effect. A typical PET foil coated with the photochromic ink can also be repeatedly light-printed for various patterns and display fabulous rewritable performance for tens of times. To sum up, this study proposes a simple method for the widespread applications of WO3-based photochromic inks.
Metal-Catalyzed C−H Bond Activation of 5-Membered Carbocyclic Rings: A Powerful Access to Azulene, Acenaphthylene and Fulvene Derivatives Chem. Asian J. (IF 4.083) Pub Date : 2018-01-05 Xinzhe Shi, Arpan Sasmal, Jean-François Soulé, Henri Doucet
Water oxidation catalysis beginning with CuCo2S4: investigation of the true electrochemically driven catalyst Chem. Asian J. (IF 4.083) Pub Date : 2018-01-04 Xiaoqiang Du, Xiaoshuang Zhang, Zhi Yang, Yaqiong Gong
Exploitation of efficient and stable water oxidation catalyst is pressing to solve the energy crisis. In this communication, the flower-like CuCo2S4 microspheres is successfully synthesized and used as an effective water oxidation catalyst. CuCo2S4/NF affords an electrocatalytic water oxidation activity with a current density of 20 mA cm-2 at a low overpotential of 260 mV. The overpotential value is lower than that of benchmark RuO2/NF (overpotential 340mV at current density of 20 mA cm-2). The water oxidation activity increases linearly before nonlinearly improving with the increasing of pH, indicating that the substrate changes from water to hydroxyl. The CuCo2S4/NF is demonstrated to be a real water oxidation catalyst based on diverse experiments.
Hierarchical nanoboxes composed of Co9S8-MoS2 nanosheets as efficient electrocatalysts for hydrogen evolution reaction Chem. Asian J. (IF 4.083) Pub Date : 2018-01-01 Vinoth Ganesan, Sunghyun Lim, Jinkwon Kim
Development of hydrogen evolution catalysts based on non-precious metals is essential for the practical application of water-splitting devices. Here, we report the synthesis of Co9S8-MoS2 hierarchical nanoboxes (HNBs) as efficient catalysts for hydrogen evolution reaction (HER). The surface of the hollow cubic structure was organized by CoMoS4 nanosheets formed by the reaction of MoS42- and Co2+ released from the Co-zeolite imidazole framework (ZIF-67) templates under reflux condition in a water-ethanol mixed solvent. The formation process of CoMoS4 HNB structures was characterized by TEM images obtained at various reaction temperatures. The amorphous CoMoS4 hierarchical nanoboxes were converted by sequential heat treatments to CoSx-MoS2 and Co9S8-MoS2 HNBs. Owing to their unique chemical compositions and structural features, Co9S8-MoS2 HNBs have high specific surface area (124.6 m2 g-1) and superior electrocatalytic performances for HER. The Co9S8-MoS2 HNBs exhibit a low overpotential (η10) of 106 mV, a low Tafel slope of 51.8 mV dec-1 and long-time stability in an acidic medium. The electrocatalytic activity of Co9S8-MoS2 HNBs is superior to the recently reported values and proves to be a promising candidate for HER.
Rational design of [13C,D14]tert-butylbenzene as a scaffold structure for designing long-lived hyperpolarized 13C probes Chem. Asian J. (IF 4.083) Pub Date : 2017-12-31 Yuki Imakura, Hiroshi Nonaka, Yoichi Takakusagi, Kazuhiro Ichikawa, Nesmine Maptue, Alexander Funk, Chalermchai Khemtong, Shinsuke Sando
Dynamic nuclear polarization (DNP) is a technique to polarize the nuclear spin population. As a result of the hyperpolarization, NMR sensitivity of the nuclei in molecules can be enhanced dramatically. Recent application of the hyperpolarization technique has led to advances in biochemical and molecular studies. A major problem is the short lifetime of the polarized nuclear spin state. Generally, in solution, the polarized nuclear spin state decays to a thermal spin equilibrium, resulting in loss of the enhanced NMR signal. This decay is correlated directly with the spin-lattice relaxation time T1. Here we report [13C,D14]tert-butylbenzene as a new scaffold structure for designing hyperpolarized 13C probes. Thanks to the minimized spin-lattice relaxation (T1) pathways, its water-soluble derivative showed a remarkably long 13C T1 value and long retention of the hyperpolarized spin state.
A small molecule Pin1 inhibitor blocks NF-κB signaling in prostate cancer cells Chem. Asian J. (IF 4.083) Pub Date : 2017-12-30 Ke-Jia Wu, Hai-Jing Zhong, Guanjun Yang, Chun Wu, Jie-Min Huang, Guodong Li, Dik-Lung Ma, Chung-Hang Leung
Prolyl-isomerase 1 (Pin1) is a conserved enzyme that regulates cell processes such as cell cycle progression, transcriptional regulation, and apoptosis. However, overexpression of Pin1 is correlated with a higher probability of prostate tumor recurrence. We utilized molecular docking technique to identify Pin1 inhibitors from a database of natural product and natural product-like compounds. The action of the hit compounds against Pin1 activity was studied using multiple methods, including a fluorimetric enzymatic assay, co-immunoprecipitation, western blotting, cell thermal shift and other techniques. We have identified compound 1 as a natural product-like inhibitor of Pin1 activity via structure-based virtual screening and showed that compound 1 could target Pin1 and disrupt the interaction between Pin1 and the p65 subunit of NF-κB in cells. Furthermore, compound 1 reduced nuclear p65 (Thr254) phosphorylation and attenuated NF-κB activity in cells. Finally, compound 1 induced apoptosis in prostate cancer cells. Compound 1 represents a natural product-like Pin1 inhibitor that acts via targeting the Pin1-NF-κB interaction.
Recent Progress of Upconversion in Nanostructured Materials: From Optical Tuning to Biomedical Applications Chem. Asian J. (IF 4.083) Pub Date : 2017-12-29 Feng Wang, Tianying Sun, Fujin Ai, Guangyu Zhu
Photon upconversion that is characterized by high-energy photon emission followed by lower-energy excitation was conventionally studied in bulk materials for several decades. The unique nonlinear luminescence process has become a subject of great attention since 2000 when upconverted emission was demonstrated in nanostructured crystals. In comparison with their bulk counterparts, nanostructured materials provide more rooms for optical fine-tuning by allowing flexible compositional integration and structural engineering. Moreover, the high colloidal stability of nanoparticles coupled with high amenability to surface functionalization opens up a number of new applications for upconversion, especially in the fields of biology and life science. In this focus review, we discuss recent development of upconversion materials through nanostructural design and review emerging biomedical applications involving these nanostructured upconversion materials. We also attempt to highlight challenging problems of these nanomaterials that constrain further progress in utilizing upconversion processes.
Catalytic water oxidation by iridium-modified carbonic anhydrase Chem. Asian J. (IF 4.083) Pub Date : 2017-12-28 Min-Chul Kim, Sang-Yup Lee
Carbonic anhydrase (CA) is a ubiquitous metalloenzyme with a Zn cofactor coordinated with trigonal histidine imidazole moieties in a tetrahedral geometry. Removal of the Zn cofactor in CA and subsequent binding of Ir afforded CA[Ir]. Under mild and neutral conditions (30 °C, pH 7), CA[Ir] exhibited water-oxidizing activity with a turnover frequency (TOF) of 39.8 min-1, comparable to those of other Ir-based molecular catalysts. Coordination of Ir to the apoprotein of CA is thermodynamically preferred and is associated with an exothermic energy change (ΔH) of −10.8 kcal/mol, implying that the CA apoprotein is stabilized by Ir binding. The catalytic oxygen-evolving activity of CA[Ir] is displayed only when Ir is bound to CA that functions as an effective biological scaffold that activates Ir center for the catalysis. The outcomes of this study indicate that the histidine imidazoles at the CA active site could be exploited as a beneficial biological ligand to provide unforeseen biochemical activity by coordination to a variety of transition metal ions.
Silver-Catalyzed Efficient Synthesis of Oxindoles and Pyrroloindolines Using α-Aminoalkylation as the Key Step Chem. Asian J. (IF 4.083) Pub Date : 2017-12-28 Kyalo Stephen Kanyiva, Sohei Makino, Takanori Shibata
α-Aminoalkylation of N-arylacrylamides with amino acid derivatives was achieved by silver-catalysis in moderate to high yields. The reaction provides a new and efficient strategy for the synthesis of functionalized oxindoles, and is suitable for a wide range of both N-arylacrylamides and amino acids, which are inexpensive and readily available. The obtained oxindoles were readily transformed into densely functionalized pyrroloindolines by deprotection and cyclization in one pot.
High Crystalline Prussian White Nanocubes as a Promising Cathode for Sodium-ion Batteries Chem. Asian J. (IF 4.083) Pub Date : 2017-12-27 Cong Li, Rui Zang, Pengxin Li, Zengming Man, Shijian Wang, Yuhan Wu, Shuaishuai Liu, Guoxiu Wang
Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room temperature sodium-ion batteries (SIBs). Herein, we report highly crystalline and Na-rich Prussian white Na2CoFe(CN)6 nanocubes synthesized by an optimized and facile co-precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na2CoFe(CN)6 nanocubes exhibited an initial capacity of 151 mA h g-1, which is close to its theoretical capacity (170 mA h g-1). Meanwhile, the Na2CoFe(CN)6 cathode demonstrated an outstanding long-term cycle performance, retaining 78% of its initial capacity after 500 cycles. Furthermore, the Na2CoFe(CN)6 Prussion white nanocubes also achieved superior rate capability (115 mA h g-1 at 400 mA g-1, 92 mA h g-1 at 800 mA g-1). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na+ ions through large channels in the open-framework. Most noteworthy, the as-prepared Na2CoFe(CN)6 nanocubes not only are low-cost in raw materials but also contain a rich sodium content (1.87 Na+ ions per lattice unit cell), which will be favorable for full cell fabrication and large-scale electric storage applications.
Alloying in an Intercalation Host: Metal Titanium Niobates as Anodes for Rechargeable Alkali-Ion Batteries Chem. Asian J. (IF 4.083) Pub Date : 2017-12-27 Aninda Jiban Bhattacharyya, Suman Das, Diptikanta Swain, Tayur N. Guru Row, Rajeev Ahuja, Rafael B. Araujo, Songxin Shi
We discuss here a unique flexible non-carbonaceous layered host viz. metal titanium niobates, M-Ti-niobate (Ti: Titanium; M: Al3+, Pb2+, Sb3+, Ba2+, Mg2+) which can synergistically store both lithium-ions and sodium-ions via simultaneous intercalation and alloying mechanisms. M-Ti-niobate is formed by ion-exchange of the K+-ions, which are specifically located inside galleries between the layers formed by edge and corner sharing TiO6 and NbO6 octahedral units in the sol-gel synthesized potassium titanium niobate (KTiNbO5). Drastic volume changes (approximately 300-400%) typically associated with alloying mechanism of storage are completely tackled chemically by the unique chemical composition and structure of the M-Ti-niobates. The free space between the adjustable Ti/Nb octahedral layers easily accommodates the volume changes. Due to the presence of an optimum amount of multivalent alloying metal ions (50-75% of total K+) in the M-Ti-niobate, efficient alloying reaction takes place directly with ions and completely eliminates any form of mechanical degradation of the electroactive particles. The M-Ti-niobate can be cycled over a wide voltage range (as low as 0.01 V) and displays remarkably stable Li+ and Na+ ion cyclability (> 2 Li+/Na+ per formula unit) for widely varying current densities over few hundreds to thousands of successive cycles. The simultaneous intercalation and alloying storage mechanisms is also studied within the density functional theory (DFT) framework. DFT expectedly shows a very small variation in the volume of Al-titanium niobate following lithium alloying. Moreover, the theoretical investigations also conclusively endorse the occurrence of the alloying process of Li-ions with the Al-ions along with the intercalation process during discharge. The M-Ti-niobates studied here demonstrates a paradigm shift in chemical design of electrodes and will pave the way for development of multitude of improved electrodes for different battery chemistries.
Photooxidation of A Twisted Isoquinolinone Chem. Asian J. (IF 4.083) Pub Date : 2017-12-24 Qichun Zhang, Gang Li, Jianfeng ZHAO, shufan yang, yongxin Li, Rakesh Ganguly
Understanding the oxidation mechanism and positions of twistacenes and twistheteroacenes under ambient conditions is very important because such knowledges can guide us to design and synthesize more novel large stable analogues. Herein, we demonstrated that a twisted isoquinolinone can decompose under oxygen and light at room temperature for the first time. The as-decomposed product 1 was fully characterized through conventional methods as well as single-crystal structure analysis. Moreover, the physical properties of the as-obtained product were carefully investigated and the possible formation mechanism was proposed.
In situ synthesis of 3D flower-like nanocrystalline Ni/C and its effect on hydrogen storage properties of LiAlH4 Chem. Asian J. (IF 4.083) Pub Date : 2017-12-23 Lei Zang, Song Liu, Huinan Guo, Xiaoya Chang, Xiangqian Xu, Lifang Jiao, Huatang Yuan, Yijing Wang
Lithium alanate (LiAlH4) is of particular interest as one of the most promising candidates for solid-state hydrogen storage. Unfortunately, high dehydrogenation temperatures, relatively slow kinetics limit its practical applications. Herein, 3D flower-like nanocrystalline Ni/C composed of highly dispersed Ni nanoparticles and interlaced carbon flakes was synthesized in-situ. The as-synthesized nanocrystalline Ni/C significantly decreased the dehydrogenation temperature and dramatically improved the dehydrogenation kinetics of LiAlH4. It is found that the LiAlH4-10wt%Ni/C sample starts hydrogen desorption at ~48 °C, which is very close to the ambient temperature. Approximately 6.3 wt% H2 is released from the LiAlH4-10wt%Ni/C within 60 min at 140 °C, whereas pristine LiAlH4 only releases 0.52 wt% H2 under identical conditions. More importantly, the dehydrogenated products can partially rehydrogenate at 300 °C and under 4 MPa H2. The synergetic effect of the flower-like carbon substrate and Ni active species contributes to the significantly reduced dehydrogenation temperatures and improved kinetics.
Dibenzothieno-pyrrolo[3,2-b]pyrrole - the Missing Member of Thienoacenes Family Chem. Asian J. (IF 4.083) Pub Date : 2017-12-22 Daniel T Gryko, Małgorzata Czichy, Mariusz Tasior, Mieczysław Łapkowski
Dibenzothieno-pyrrolo[3,2-b]pyrrole and the corresponding bis(S,S-dioxide) were synthesised using concise synthetic strategy. Despite the presence of six fused aromatic rings, π-expanded pyrrolo[3,2-b]pyrroles of this type absorb and emit at relatively short wavelengths, which reflects inefficient π-conjugation due to the angular arrangement of aromatic rings. They exhibit interesting and complex electrochemical behavior, highlighting their potential in organic electronics. Both heteroacenes undergo two-stage oxidation, while remaining the independence of each 1-phenyl-1H-benzothieno[3,2-b]pyrrole, which was proved by in situ ESR measurements. Interestingly, electrochemically generated dicationdiradicals are not only distributed over the pyrrolo[3,2-b]pyrrole scaffold, but also over the phenyl substituents located on nitrogen atoms.
Nickel-Catalyzed Heck-Type Monofluoroacetation of Styrenes for Facile Synthesis of Allylic Fluorides Chem. Asian J. (IF 4.083) Pub Date : 2017-12-21 Xi-Sheng Wang, Zhen-Yu Wang, Jia-Hao Wan, Gao-Yin Wang, Ruo-Xing Jin, Quan Lan
An efficient nickel-catalyzed Heck-type reaction between styrenes and fluoroalkyl iodine has been developed. This novel transformation has demonstrated broad substrate scope, mild reaction conditions and excellent E-stereoselectivity. This efficient synthetic method has been applied into the late-stage monofluoroacetation of biologically active molecules. Mechanistic investigations indicate that a monofluoroalkyl radical is involved in the catalytic cycle.
Redox-Active Peptide Functionalized Quinquethiophene Based Electrochromic π-Gel Chem. Asian J. (IF 4.083) Pub Date : 2017-12-21 Apurba K Das, Maruthi Konda, Sayan Maity, Rohit G Jadhav
Here, we report an electrochromic system based on self-assembled dipeptide appended redox active quinquethiophene π-gel. The designed peptide-quinquethiophene consists of a symmetric bolaamphiphile that has two segments: a redox active π-conjugated quinquethiophene core for electrochromism and peptide-motif for the involvement of molecular self-assembly. Investigations reveal that self-assembly and electrochromic properties of the π-gel are strongly dependent on the relative orientation of peptidic and quinquethiophene scaffolds in the self-assembling system. The colors of the π-gel film are very stable with fast and controlled switching speed at room temperature.
Mild-Base-Promoted Arylation of (Hetero)Arenes with Anilines Chem. Asian J. (IF 4.083) Pub Date : 2017-12-21 Diego Manuel Monzón, Tanausú Santos, Fernando Pinacho-Crisóstomo, Víctor Sotero Martín, Romen Carrillo
Transition metal-free radical arylation of heteroarenes is achieved at room temperature by simply adding aqueous sodium carbonate to a solution of the corresponding heteroarene and arenediazonium salt, which can even be formed in situ. Such an easy, inexpensive and mild methodology has been optimized and applied to the expeditious modification of interesting molecular cores like naphthylimide or bisthienylcyclopentenes.
Applicability Evaluation of a Bright Green Emitting Carbon dots in Solid States for White Light Emitting Diodes Chem. Asian J. (IF 4.083) Pub Date : 2017-12-19 Deyin Wang
A self-quenching-resistant and bright green emitting carbon dots (CDs) in solid state is synthesized via a facile hydrothermal method. Their structure, optical properties together with their thermal and photo-stabilities, as well as their applicability in white LEDs are investigated. The obtained CDs have nearly spherical shape with size around 4~5 nm. The resulting powder CDs show excitation-independent emission behavior, and can be excited over a broad range from 300-450 nm. Under optimal excitation at 400 nm, the resultant powder CDs yield bright and broad green emission around 505 nm with full width at half maximum (FWHM) about 110 nm. Time resolved and temperature dependent luminescence spectra suggest that the luminescence origin of the resulting CDs is one single species. The potential application of the green emitting CDs is evaluated by constructing a white light-emitting diodes lamp. The fabricated white LEDs lamp emitted bright warm white light with excellent color rendering properties (a color rendering index of 86.9 and correlated color temperature of 3863 K ).
Visible-light-driven efficient photocatalytic reduction of organic azides to amine over CdS sheet-rGO nanocomposite Chem. Asian J. (IF 4.083) Pub Date : 2017-12-19 Subhash Chandra Ghosh
CdS sheet-rGO nanocomposite as heterogeneous photocatalyst enables visible light induced photocatalytic-reduction of aromatic, heteroaromatic, aliphatic and sulfonyl azides to the corresponding amines using hydrazine hydrate as a reductant. The reaction shows excellent conversion and chemoselectivity towards the formation of the amine without self-photoactivated azo compounds. In the adopted strategy, CdS not only accelerate the formation of nitrene through photo-activation of azide but also enhance the decomposition of azide to a certain extent which entirely suppressed the azo compound formation. The developed catalyst CdS sheet-rGO nanocomposite is very active to provide excellent results under 40W simple household CFL lamp.
Graphene Based Inverted Planar Perovskite Solar Cells: Advancements, Fundamental Challenges and Prospects Chem. Asian J. (IF 4.083) Pub Date : 2017-12-18 Konstantinos Petridis, George Kakavelakis, Minas Stylianakis, Emmanuel Kymakis
Metal halide based perovskite solar cells are considered among the most promising photovoltaic technologies already presenting certified efficiencies surpassing 22%. The high performance and the low fabrication cost, makes this technology competitive with state-of-the-art thin film photovoltaics. However perovskite solar cells present some striking disadvantages hindering their commercialization, including low operational lifetimes, high toxicity and hysteresis effect, which lower both the performance, and long term stability of the devices. In this focus review article, we summarize the work that has been done within the last two years regarding the addressing of challenges of low temperature processed planar inverted PSCs, using graphene based materials. In addition, we discuss the critical challenges and the prospects of this field and propose some prospects for future research directions.
Continuous Scientific Growth through an Open-Minded Attitude Chem. Asian J. (IF 4.083) Pub Date : 2017-12-15 Susumu Kitagawa
Highlights on the Road towards Highly Emitting Solid-State Luminophores: Two Classes of Thiazole-Based Organoboron Fluorophores with the AIEE/AIE Effect Chem. Asian J. (IF 4.083) Pub Date : 2017-12-14 Kseniya Lugovik, Alexander Eltyshev, Polina Suntsova, Pavel Slepukhin, Enrico Benassi, Nataliya P. Belskaya
Abstract: Developing a novel, small-sized molecular building block that may be capable of emitting light in the solid state is a challenging task and has rarely been reported in the literature. BF2-containing dyes seem to be promising candidate towards this aim. Two series of new N^NBF2-complexes showing aggregation-induced emission (AIE) and aggregation-induced emission enhancement (AIEE) were designed and synthesized via a new protocol, which improves on the traditional method by employing microwave irradiation. The optical and photophysical properties of the BF2 complexes were investigated in depth. The synthesized complexes showed fluorescence in both solution and the solid state and, in a THF/water mixture, may aggregate into fluorescent nanoparticles. The experimental investigation was supported by quantum mechanical calculations. Their availability, stability, large Stokes shifts and aggregation capabilities, along with their solid-state emission capability, render this new class of BF2-complexes promising AIEE/AIE fluorophores for further applications in the fields of fluorescence imaging and material sciences.
Iron-Catalyzed Aminative Cyclization/Intermolecular Homolytic Aromatic Substitution Using Oxime Esters and Simple Arenes Chem. Asian J. (IF 4.083) Pub Date : 2017-12-13 Takuya Shimbayashi, Kazuhiro Okamoto, Kouichi Ohe
Intermolecular C-H alkylation of simple arenes in the presence of an iron catalyst has been achieved in a cascade manner with an aminative cyclization triggered by N-O bond cleavage of an alkene-tethered oxime ester. Various arenes, including electron-rich and electron-poor arenes, and heteroarenes can be employed in the reaction system. Regioselectivity and radical trapping experiments support the involvement of alkyl radical species, which undergo a homolytic aromatic substitution (HAS) to afford the arylation products.
A Novel trans-1-(9-Anthryl)-2-phenylethene Derivative Containing a Phenanthroimidazole Unit for Application in Organic Light-Emitting Diodes Chem. Asian J. (IF 4.083) Pub Date : 2017-12-12 Nonglin Zhou, Shirong Wang, Yin Xiao, Xianggao Li
Converging and Integrating Our Knowledge to Sustain Humanity Chem. Asian J. (IF 4.083) Pub Date : 2017-12-12 Ryoji Noyori
Constraining the Teratogenicity of Pesticide Pollution by a Synthetic Nanoreceptor Chem. Asian J. (IF 4.083) Pub Date : 2017-12-12 Xue Yang, Shengke Li, Ziyi Wang, Simon M. Y. Lee, Lian-Hui Wang, Ruibing Wang
Diketopyrrolopyrrole-based and tetracyano-bridged small molecules for bulk heterojunction organic solar cells Chem. Asian J. (IF 4.083) Pub Date : 2017-12-08 Rajneesh Misra
The research on bulk heterojunction (BHJ) organic solar cells (OSCs) is rapidly growing from the past two decades and the device performance has reached power conversion efficiency over 13%. In this minireview we have highlighted the design strategies used for the development of diketopyrrolopyrrole (DPP) and tetracyano based molecular donors. We have also described how tetracyano bridged non-fullerene acceptors can be developed by click type [2+2] cycloaddition-retroelectrocyclization reaction of acetylene bridged small molecule with tetracyanoethylene (TCNE) by simple modification.
Surfactant-dependent charge transfer between polyoxometalate and single-walled carbon nanotubes: a fluorescence spectroscopic study Chem. Asian J. (IF 4.083) Pub Date : 2017-12-11 Liu Hong, Naotoshi Nakashima, Yunxing Li, Hongbing Jia, Cheng Yang
Hybridizations of redox-active polyoxometalates (POMs) with single-walled carbon nanotubes (SWNTs) have been widely investigated for their diverse applications. For the purpose of constructing high quality electronic devices, controlling the charge transfer within POM/SWNTs hybrid is an inevitable issue. By means of fluorescence spectroscopy, we demonstrate the electron transfer between SWNTs and a common POM dopant phosphomolybdic acid (PMo12) can be tuned simply by an alteration of nanotube surfactant type from anionic to non-ionic. The mechanism is attributed to the influence of surfactant type on the stabilization of electron donor-acceptor hybrid and effect of surfactant-nanotube interaction. Our results will be important to control charge transport behavior in nanohybrids consisted of carbon nanotubes.
Block Copolymer Self-Assembly in Solution - Quo vadis? Chem. Asian J. (IF 4.083) Pub Date : 2017-12-11 Felix Helmut Schacher, Johannes Brendel
The desire for increasing complexity while maintaining control over every aspect of the process itself - this might be used as a provocative description of the developments in block copolymer self-assembly in solution over the last decade. The community has witnessed tremendous progress, not only with regard to the design of building blocks, but also in terms of understanding assembly pathways, interfacial properties, or kinetic obstacles. In particular, the latter can be of interest (and actually turned into an advantage), if structures are targeted, which are not in thermodynamic equilibrium. Within this focus review, we try to highlight the key developments and trends that we identified during the last five years: the development of step-wise and dynamic processes, different means to impart further hierarchy into solution-borne nanostructures, and a partial shift in focus towards gradient and bottlebrush block copolymers.
Laccase-catalyzed synthesis of low molecular weight lignin-like oligomers and their application as UV blocking materials Chem. Asian J. (IF 4.083) Pub Date : 2017-12-06 Balamurugan Ramalingam, Jieyan Lim, Ranganathan Krishnan, Jayasree Seayad, Barindra Sana, Farid John Ghadessy, Satyasankar Jana
Laccase-catalyzed oxidative polymerization of monomeric and dimeric lignin model compounds was carried out using oxygen as oxidant in aqueous medium. The oligomers were characterized by gel permeation chromatography (GPC) and matrix assisted laser desorption ionisation time-of-flight mass spectroscopy (MALDI-TOF-MS) analysis. The oxidative polymerization leads to the formation of oligomeric species with a number average molecular weight (Mn) ranging between 700-2300 Da with low polydispersity index. Spectroscopic analysis provided insight into the possible modes of linkages present in the oligomers and the oligomerization is likely to proceed through the formation of C-C linkages between phenolic aromatic rings. The oligomers were found to show good ultraviolet (UV) light absorption characteristics with high molar extinction coefficient (5000-38000 M-1cm-1) in the UV spectral region. The oligomers were blended independently with polyvinyl chloride (PVC) by solution blending. Ultraviolet visible (UV-Vis) transmittance spectra of the oligomer embedded PVC films indicated that these lignin-like oligomers possess notable UV light blocking ability. In particular, the oligomers obtained from vanillyl alcohol and dimeric lignin model was found to show good photostability by accelerated UV weathering experiments. The UV blocking characteristics and photostabilty were finally compared with the low molecular weight commercial UV stabilizer 2,4-dihydroxybenzophenone.
Conjugated Microporous Polymers for Heterogeneous Catalysis Chem. Asian J. (IF 4.083) Pub Date : 2017-12-07 Yun-Bing Zhou, Zhuang-Ping Zhan
3D Porous Carbon Framework Stabilized Ultra-Uniform Nano γ-Fe2O3: A Useful Catalyst System Chem. Asian J. (IF 4.083) Pub Date : 2017-12-07 Yongjian Ai, Mengqi He, Qianrui Lv, Lei Liu, Hong-bin Sun, Mingyu Ding, Qionglin Liang
Synthesis and Application of Rylene Imide Dyes as Organic Semiconducting Materials Chem. Asian J. (IF 4.083) Pub Date : 2017-12-07 Jiajing Feng, Wei Jiang, Zhaohui Wang
Constraining the Teratogenicity of Pesticide Pollution by a Synthetic Nanoreceptor Chem. Asian J. (IF 4.083) Pub Date : 2017-12-06 Xue Yang, Shengke Li, Ziyi Wang, Simon M. Y. Lee, Lian-Hui Wang, Ruibing Wang
Self-Template Synthesis of Hybrid Porous Co3O4-CeO2 Hollow Polyhedrons for High Performance Supercapacitors Chem. Asian J. (IF 4.083) Pub Date : 2017-12-05 Chengzhen Wei, Kangfei Liu, Jing Tao, Xiaoting Kang, Haiyan Hou, Cheng Cheng, Daojun Zhang
In this work, hybrid porous Co3O4-CeO2 hollow polyhedrons have been successfully achieved via a simple cation-exchange route followed by heat treatment. In the synthesis process, ZIF-67 polyhedrons frameworks are firstly prepared, which not only serve as a host for the exchanged Ce3+ ions, but also act as the template for the synthesis of hybrid porous Co3O4-CeO2 hollow polyhedrons. When utilized as electrode materials for supercapacitors, the hybrid porous Co3O4-CeO2 hollow polyhedrons delivered a large specific capacitance of 1288.3 F g-1 at 2.5 A g-1 and a remarkable long lifespan cycling stability (less 3.3 % loss after 6000 cycles). Furthermore, an asymmetric supercapacitor (ASC) device based on hybrid porous Co3O4-CeO2 hollow polyhedrons was assembled. The ASC device possesses an energy density of 54.9 Wh kg-1, which can be yet retained 44.2 W h kg-1 even at a power density of 5100 W Kg-1, indicating its promising applications in electrochemical energy storage. More importantly, we believe that the present route is a simple and versatile strategy for preparation other hybrid metal oxides with desired structures, chemical compositions and applications
Self-Complementary Dimers of Oxalamide-Functionalized Resorcinarene Tetrabenzoxazines Chem. Asian J. (IF 4.083) Pub Date : 2017-12-05 Kari Rissanen, Mario Cetina, Zoran Dzolic, Ngong Kodiah Beyeh, Lotta Turunen
Self-complementarity is a useful concept in supramolecular chemistry, molecular biology and polymeric systems. Two resorcinarene tetrabenzoxazines decorated with four oxalamide groups are synthesized and characterized. The oxalamide groups possessed self-complementary hydrogen bonding sites between the carbonyls and amide groups. The self-complementary nature of the oxalamide groups resulted in self-included dimeric assemblies. The hydrogen bonding interactions within the tetrabenzoxazines give rise to the formation of dimers, which are confirmed by single crystal X-ray diffractions analysis and supported by NMR spectroscopy and mass spectrometry. The self-included dimers are linked by numerous and strong intermolecular interactions, forming one-dimensional polymers, which are then further linked into three-dimensional networks.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
- Acc. Chem. Res.
- ACS Appl. Mater. Interfaces
- ACS Biomater. Sci. Eng.
- ACS Catal.
- ACS Cent. Sci.
- ACS Chem. Biol.
- ACS Chem. Neurosci.
- ACS Comb. Sci.
- ACS Earth Space Chem.
- ACS Energy Lett.
- ACS Infect. Dis.
- ACS Macro Lett.
- ACS Med. Chem. Lett.
- ACS Nano
- ACS Omega
- ACS Photonics
- ACS Sens.
- ACS Sustainable Chem. Eng.
- ACS Synth. Biol.
- Acta Biomater.
- Acta Mater.
- Adv. Colloid Interface Sci.
- Adv. Electron. Mater.
- Adv. Energy Mater.
- Adv. Funct. Mater.
- Adv. Healthcare Mater.
- Adv. Mater.
- Adv. Mater. Interfaces
- Adv. Opt. Mater.
- Adv. Sci.
- Adv. Synth. Catal.
- AlChE J.
- Anal. Bioanal. Chem.
- Anal. Chem.
- Anal. Chim. Acta
- Anal. Methods
- Angew. Chem. Int. Ed.
- Annu. Rev. Anal. Chem.
- Annu. Rev. Biochem.
- Annu. Rev. Food Sci. Technol.
- Annu. Rev. Mater. Res.
- Annu. Rev. Phys. Chem.
- Appl. Catal. A Gen.
- Appl. Catal. B Environ.
- Appl. Clay. Sci.
- Appl. Energy
- Aquat. Toxicol.
- Arab. J. Chem.
- Asian J. Org. Chem.
- Atmos. Environ.
- Carbohydr. Polym.
- Catal. Commun.
- Catal. Sci. Technol.
- Catal. Today
- Cell Chem. Bio.
- Cem. Concr. Res.
- Ceram. Int.
- Chem. Asian J.
- Chem. Bio. Drug Des.
- Chem. Biol. Interact.
- Chem. Commun.
- Chem. Educ. Res. Pract.
- Chem. Eng. J.
- Chem. Eng. Sci.
- Chem. Eur. J.
- Chem. Mater.
- Chem. Phys.
- Chem. Phys. Lett.
- Chem. Phys. Lipids
- Chem. Rev.
- Chem. Sci.
- Chem. Soc. Rev.
- Combust. Flame
- Compos. Part A Appl. Sci. Manuf.
- Compos. Sci. Technol.
- Compr. Rev. Food Sci. Food Saf.
- Comput. Chem. Eng.
- Constr. Build. Mater.
- Coordin. Chem. Rev.
- Corros. Sci.
- Crit. Rev. Food Sci. Nutr.
- Crit. Rev. Solid State Mater. Sci.
- Cryst. Growth Des.
- Curr. Opin. Chem. Eng.
- Curr. Opin. Colloid Interface Sci.
- Curr. Opin. Environ. Sustain
- Curr. Opin. Solid State Mater. Sci.
- Ecotox. Environ. Safe.
- Electrochem. Commun.
- Electrochim. Acta
- Energy Environ. Sci.
- Energy Fuels
- Environ. Impact Assess. Rev.
- Environ. Int.
- Environ. Model. Softw.
- Environ. Pollut.
- Environ. Res.
- Environ. Sci. Policy
- Environ. Sci. Technol.
- Environ. Sci. Technol. Lett.
- Environ. Sci.: Nano
- Environ. Sci.: Processes Impacts
- Environ. Sci.: Water Res. Technol.
- Eur. J. Inorg. Chem.
- Eur. J. Med. Chem.
- Eur. J. Org. Chem.
- Eur. Polym. J.
- J. Acad. Nutr. Diet.
- J. Agric. Food Chem.
- J. Alloys Compd.
- J. Am. Ceram. Soc.
- J. Am. Chem. Soc.
- J. Am. Soc. Mass Spectrom.
- J. Anal. Appl. Pyrol.
- J. Anal. At. Spectrom.
- J. Antibiot.
- J. Catal.
- J. Chem. Educ.
- J. Chem. Eng. Data
- J. Chem. Inf. Model.
- J. Chem. Phys.
- J. Chem. Theory Comput.
- J. Chromatogr. A
- J. Chromatogr. B
- J. Clean. Prod.
- J. CO2 UTIL.
- J. Colloid Interface Sci.
- J. Comput. Chem.
- J. Cryst. Growth
- J. Dairy Sci.
- J. Electroanal. Chem.
- J. Electrochem. Soc.
- J. Environ. Manage.
- J. Eur. Ceram. Soc.
- J. Fluorine Chem.
- J. Food Drug Anal.
- J. Food Eng.
- J. Food Sci.
- J. Funct. Foods
- J. Hazard. Mater.
- J. Hydrol.
- J. Ind. Eng. Chem.
- J. Inorg. Biochem.
- J. Magn. Magn. Mater.
- J. Mater. Chem. A
- J. Mater. Chem. B
- J. Mater. Chem. C
- J. Mater. Process. Tech.
- J. Mech. Behav. Biomed. Mater.
- J. Med. Chem.
- J. Membr. Sci.
- J. Mol. Catal. A Chem.
- J. Mol. Liq.
- J. Nat. Gas Sci. Eng.
- J. Nat. Prod.
- J. Nucl. Mater.
- J. Org. Chem.
- J. Photochem. Photobiol. C Photochem. Rev.
- J. Phys. Chem. A
- J. Phys. Chem. B
- J. Phys. Chem. C
- J. Phys. Chem. Lett.
- J. Porphyr. Phthalocyanines
- J. Power Sources
- J. Solid State Chem.
- J. Taiwan Inst. Chem. E.
- Macromol. Rapid Commun.
- Mass Spectrom. Rev.
- Mater. Chem. Front.
- Mater. Des.
- Mater. Horiz.
- Mater. Lett.
- Mater. Sci. Eng. A
- Mater. Sci. Eng. R Rep.
- Mater. Today
- Meat Sci.
- Med. Chem. Commun.
- Microchem. J.
- Microchim. Acta
- Micropor. Mesopor. Mater.
- Mol. Biosyst.
- Mol. Cancer Ther.
- Mol. Catal.
- Mol. Nutr. Food Res.
- Mol. Pharmaceutics
- Mol. Syst. Des. Eng.
- Nano Energy
- Nano Lett.
- Nano Res.
- Nano Today
- Nano-Micro Lett.
- Nanoscale Horiz.
- Nat. Catal.
- Nat. Chem.
- Nat. Chem. Biol.
- Nat. Commun.
- Nat. Energy
- Nat. Mater.
- Nat. Med.
- Nat. Methods
- Nat. Nanotech.
- Nat. Photon.
- Nat. Prod. Rep.
- Nat. Protoc.
- Nat. Rev. Chem.
- Nat. Rev. Drug. Disc.
- Nat. Rev. Mater.
- Neurochem. Int.
- New J. Chem.
- NPG Asia Mater.
- npj 2D Mater. Appl.
- npj Comput. Mater.
- npj Flex. Electron.
- npj Mater. Degrad.
- npj Sci. Food
- Pharmacol. Rev.
- Pharmacol. Therapeut.
- Photochem. Photobiol. Sci.
- Phys. Chem. Chem. Phys.
- Phys. Life Rev.
- PLOS ONE
- Polym. Chem.
- Polym. Degrad. Stabil.
- Polym. J.
- Polym. Rev.
- Powder Technol.
- Proc. Combust. Inst.
- Prog. Cryst. Growth Ch. Mater.
- Prog. Energy Combust. Sci.
- Prog. Mater. Sci.
- Prog. Photovoltaics
- Prog. Polym. Sci.
- Prog. Solid State Chem.