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61.
A facile, efficient and environment friendly method is established to prepare poly(vinyl alcohol)(PVA) based graphene oxide-montmorillonite(GO-MMT) nanocomposites in aqueous media. GO-MMT nanohybrid is obtained by the combination of GO and MMT in water without any reducing or stabilizing agents. The formation of GO-MMT nanohybrid is due to the hydrogen bonding and crosslinking effects. The sodium ions within MMT sheets act as crosslinkers between GO sheets and MMT platelets. The resultant nanocomposites are characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA) and mechanical testing. Compared to that of pure PVA, PVA nanocomposites show enhanced thermal stabilities and mechanical properties, which results from strong interfacial adhesion of the nanoadditives in PVA matrix. The further increase in the tensile strength and modulus results from strong interaction between PVA chains and layered GO-MMT as well as good mechanical properties of GO-MMT hybrid, compared to PVA/GO and PVA/MMT nanocompsoites. 相似文献
62.
Journal of Computer-Aided Molecular Design - A new method has been proposed to understand and predict the stability of nitro compounds. This method uses the maximum electron densities at the... 相似文献
63.
Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors 下载免费PDF全文
Dr. Pengchong Xue Boqi Yao Panpan Wang Peng Gong Zhenqi Zhang Prof. Ran Lu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(48):17508-17515
An L ‐phenylalanine derivative ( C12PhBPCP ) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self‐assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self‐assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H‐aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self‐assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively. 相似文献
64.
Diastereoselective Synthesis of Cyclopentanoids: Applications to the Construction of the ABCD Tetracyclic Core of Retigeranic Acid A 下载免费PDF全文
Junlin Zhang Xiao Wang Shuang Li Dian Li Song Liu Prof. Dr. Yu Lan Dr. Jianxian Gong Prof. Dr. Zhen Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(36):12596-12600
A concise and efficient approach for the construction of the tetracyclic carbon skeleton of retigeranic acid A is described. The key transformations include a novel Rh‐catalyzed [3+2] cycloaddition of enyol to afford cyclopentanoid E , bearing two contiguous quaternary stereocenters at the bridgehead positions, and an intramolecular Pauson–Khand reaction to construct the advanced tetracyclic core structure of retigeranic acid A. 相似文献
65.
Inside Back Cover: A Multifunctional Bimetallic Molecular Device for Ultrasensitive Detection,Naked‐Eye Recognition,and Elimination of Cyanide Ions (Chem. Eur. J. 37/2015) 下载免费PDF全文
66.
Liquid‐Crystalline Mesogens Based on Cyclo[6]aramides: Distinctive Phase Transitions in Response to Macrocyclic Host–Guest Interactions 下载免费PDF全文
Xiaowei Li Dr. Bao Li Long Chen Jinchuan Hu Chengdanyang Wen Prof. Qingdong Zheng Prof. Lixin Wu Dr. Huaqiang Zeng Prof. Bing Gong Prof. Lihua Yuan 《Angewandte Chemie (International ed. in English)》2015,54(38):11147-11152
Producing macrocyclic mesogens that are responsive to guest encapsulation presents a significant challenge. Cyclo[6]aramides, a type of macrocycle with a hydrogen‐bond‐constrained backbone, exhibit thermotropic lamellar, discotic nematic, hexagonal, and rectangular columnar mesophases over a considerably wide temperature range, including at room temperature. Additionally, cyclo[6]aramides show unusual mesophase transitions from lamellar to hexagonal columnar phase mediated by macrocyclic host–guest (H–G) interactions between the macrocycles and alkylammonium salts. The phase transition, triggered by an organic guest engaging in H–G interactions with a macrocyclic cavity, provides a novel strategy for manipulating the properties of liquid‐crystalline materials. The crystal structure of a homologous cyclo[6]aramide reveals a disk‐shaped, near‐planar molecular backbone that facilitates intermolecular π–π stacking and leads to columnar assembly. 相似文献
67.
Chun‐Hua Yang Yu‐Shi Zhang Wen‐Wen Fan Dr. Gong‐Qing Liu Prof. Dr. Yue‐Ming Li 《Angewandte Chemie (International ed. in English)》2015,54(43):12636-12639
A direct and catalyst‐free method for the intramolecular aminoboration of unfunctionalized olefins is reported. In the presence of BCl3 (1 equiv) as the sole boron source, intramolecular aminoboration of sulfonamide derivatives of 4‐penten‐1‐amines, 5‐hexen‐1‐amines, and 2‐allylanilines proceeded readily without the use of any catalyst. The boronic acids obtained after hydrolysis could be converted into the corresponding pinacol borates in a straightforward manner by treatment with pinacol under anhydrous conditions. 相似文献
68.
Rhodium(I)‐Catalyzed Regiospecific Dimerization of Aromatic Acids: Two Direct CH Bond Activations in Water 下载免费PDF全文
Dr. Hang Gong Dr. Huiying Zeng Dr. Feng Zhou Prof. Dr. Chao‐Jun Li 《Angewandte Chemie (International ed. in English)》2015,54(19):5718-5721
2,2′‐Diaryl acids are key building blocks for some of the most important and high‐performance polymers such as polyesters and polyamides (imides), as well as structural motifs of MOFs (metal–organic frameworks) and biological compounds. In this study, a direct, regiospecific and practical dimerization of simple aromatic acids to generate 2,2′‐diaryl acids has been discovered, which proceeds through two rhodium‐catalyzed C? H activations in water. This reaction can be easily scaled up to gram level by using only 0.4–0.6 mol % of the rhodium catalyst. As a proof‐of‐concept, the natural product ellagic acid was synthesized in two steps by this method. 相似文献
69.
Assoc. Prof. Dr. Tuo Wang Prof. Dr. Jinlong Gong 《Angewandte Chemie (International ed. in English)》2015,54(37):10718-10732
Solar water splitting provides a clean and renewable approach to produce hydrogen energy. In recent years, single‐crystal semiconductors such as Si and InP with narrow band gaps have demonstrated excellent performance to drive the half reactions of water splitting through visible light due to their suitable band gaps and low bulk recombination. This Minireview describes recent research advances that successfully overcome the primary obstacles in using these semiconductors as photoelectrodes, including photocorrosion, sluggish reaction kinetics, low photovoltage, and unfavorable planar substrate surface. Surface modification strategies, such as surface protection, cocatalyst loading, surface energetics tuning, and surface texturization are highlighted as the solutions. 相似文献
70.
Prof. Dr. Suning Wang Deng‐Tao Yang Jiasheng Lu Hiroyuki Shimogawa Prof. Dr. Shaolong Gong Xiang Wang Soren K. Mellerup Prof. Dr. Atsushi Wakamiya Dr. Yi‐Lu Chang Prof. Dr. Chuluo Yang Prof. Dr. Zheng‐Hong Lu 《Angewandte Chemie (International ed. in English)》2015,54(50):15074-15078
New BN‐heterocyclic compounds have been found to undergo double arene photoelimination, forming rare yellow fluorescent BN‐pyrenes that contain two B? N units. Most significant is the discovery that the double arene elimination can also be driven by excitons generated electrically within electroluminescent (EL) devices, enabling the in situ solid‐state conversion of BN‐heterocycles to BN‐pyrenes and the use of BN‐pyrenes as emitters for EL devices. The in situ exciton‐driven elimination (EDE) phenomenon has also been observed for other BN‐heterocycles. 相似文献