Fluorescent carbon microspheres (CMSs) and carbon nanodots (CNDs) synthesized together in one pot have received much attention in the past decade. Here we report the use of L-and D-ascorbic acids (AA) to prepare CMSs with different chirality and CNDs with different fluorescent emission by the hydrothermal method. The CMSs emit a blue light while the CNDs emit a green one under 365 nm UV light. The reaction conversions of CMSs prepared with this method are over 25% when the reaction temperature is above 180 degrees C. Circular di-chroism, specific rotation, and photoluminescence of CMSs were measured. The analyses show that the L-and D -AA-based CMSs exhibit different chiral spectra. The graphene-like structures of CMSs are revealed by Raman spectroscopy. A possible formation mechanism of the CMSs and CNSs is proposed. In addition, the CMSs after calcination were found to achieve higher electrical and thermal conductivities comparable to those of the commercial carbon black. Photoluminescence analyses of CNDs show that the relative fluctuation between the blue and green emissions determines the shifting of blue and green hybrid color of the synthesized CNDs. D-AA derived CNDs show a higher quantum yield (QY) close to 1% and a stronger green emission. The blue-emitting CNDs and the green-emitting ones could be separated with the larger green CNDs kept inside the dialysis tube.

A simple and novel electrochemical sensor based on a hydrophilic single-walled carbon nanohorn (SWCNH) modified glassy carbon electrode (GCE) was designed for the determination of acetaminophen (APAP). The hydrophilic SWCNH/GCE was characterized using Transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffractometer (XRD), and X-ray photoelectron spectroscopy (XPS). This proposed sensor exhibits remarkable performance for the electrocatalytic detection of APAP. The hydrophilic SWCNH/GCE shows a good differential pulse voltammetry (DPV) response at APAP concentration from 100 to 1000 μ M with sensitivity and a detection limit of 2.63 μ A μ M −1 cm −2 and 1 μ M. Regarding the reaction mechanism, the hydrophilic SWCNH/GCE could easily electro-catalyze APAP oxidation to form N-acetyl-p-benzoquinone-imine (NAPQI). Then NAPQI is rapidly degraded to p-benzoquinone in solutions of 0.1 M Na 2 SO 4 and 0.05 M H 2 SO 4 at pH 1.

Abstract Hydrophilic single-wall carbon nanohorns (SWNHs) are produced by using the arc-in-water method. These hydrophilic SWNHs are easily formed in clusters with a diameter of ∼30–40 nm. The XRD pattern features a peak at around 26°, which is typical for SWCNHs. There are evidences of C–C, C=C, C–O, C=O and O=C–O– bonding units based on the XPS spectra of hydrophilic SWNHs. The Raman spectra show that the hydrophilic SWNHs have a high number of defects. Furthermore, stretching vibration bands of C–O, C=C, O=C–O–, C–H and O–H units have been observed by FTIR measurements. All these spectroscopic results are consistent with the structural concepts.

Charge transport bearing 9,10-diphenylanthracene derivatives for true blue and efficiency enhancing electroluminance.

Carbon nanofibers (CNFs) have wide applications in energy storage devices, electrically conducting composites, selective adsorbents, and catalyst supports. Catalytic chemical vapor deposition was carried out in this work to synthesize CNFs at mild temperatures of 700 and 800 degrees C. Non-ferromagnetic metal complexes of La, Nb, and Ti, spread on porous NaX-type zeolite support, were tested as new catalyst. CNFs ranging from 30 to 200 nm in diameter were obtained. Images of transmission electron microscopy showed encapsulated transition-metal nanoparticles by CNFs. X-ray diffraction patterns revealed the crystalline structures of La (FCC), Nb (BCC), and Ti (HCP) formed over zeolite. Magnetic hysteresis loops showed superconductivity from the CNF-encapsulated Nb at 2 K. Raman spectra showed that all the samples possessed graphitic and amorphous carbon structures. Based on the SEM images and Raman spectra, the three metals all catalyzed the synthesis of CNFs.

Fluorine-based amphiphobic coatings have been widely used in commercial textiles to provide water-and oil-repelling abilities. However, few reports from the literature survey have discussed the surface structural effects of the coated substrate on amphiphobicity. In this research, various thickness amphiphobic coatings based on mixed epoxy, tetraethylorthosilicate, and a particular alkoxysilane with fluorinated side chains (F-silane) were deposited on Grade 420 stainless steel plates. Film amphiphobicity is characterized by measuring the water and oil contact angles of the coating. Film morphology is examined using atomic force microscopy. The deposited films free of F-silane are thinner than 150 nm. The films become thick at high F-silane volume percentage with the surface cavities, ridges, and granules being masked out. On the addition of F-silane, the water contact angle of the deposited films increases up to 105 degrees and then reaches a plateau of similar to 107 degrees with increasing F-silane. In contrast, the oil contact angle increases up to 60 degrees at first and then slowly declines with the F-silane concentration. The total drop of oil contact angle by similar to 20 degrees was attributed to the masking out of surface features on film thickening. This indicates that the surface oleophobicity depends on surface structures. Therefore, improving surface amphiphobicity correlates with creating more refined multiscale surface structures during the industrial manufacturing process of steel plate, prior to surface modification by F-silane. (C) 2014 Wiley Periodicals, Inc.

Synthetic thalidomide analogues (compounds 1 – 35 ), including phenylphthalimide, pyridylphthalimide, aminobenzylphthalimide, and diphenylazophthalimide, were tested for their cytotoxic effects on human cancer cell lines Hep2 (Human Larynx Carcinoma Cells), HL-60 (Human Myeloid Leukemia Cells), NUGC (Human Gastric Carcinoma Cells), and HONE-1 (Human Nasopharyngeal Carcinoma Cells) because the incidence rate is more prominent in Asian countries than in Western countries. Compounds 17 , 27 , 28 , and 35 were found to have antitumor activity in Hep2 and HL-60 cell lines. Compounds 2 , 4 , 15 , 17 , 19 , 20 , 23 , and 27 can inhibit nitric oxide (NO) synthase activity by more than 90%. These thalidomide analogues were found to be potent inducible nitric oxide synthase (iNOS) inhibitors, and the iNOS inhibiting potential of compounds 17 and 27 might be an advantage for anticancer therapy. In conclusion, inhibition of NO synthesis is a new development in cancer therapy for now and in the future. We modified the structures of the thalidomide analogues to have a stronger anticancer effect and a good therapeutic effect.

A series of Cu(II) compounds containing neutral multi-dentate ligand [2,6-diisopropylphenyl]-bis[(1-Hpyrazol-1-yl)methyl] amine (L-1) and pyrazole dimethoxethyl ligand [(1-H-pyrazol-1-yl)methyl]-bis(2-methoxyethyl)amine (L-2) were synthesized. Reactions of L-1 and L-2 with copper(II) chloride generate LICuCl2 (1). and L2CuCl2 (2), respectively. Compounds 1 and 2 have been characterized by elemental analysis and X-ray single crystal diffractometry. The effects of compounds 1 and 2 on the cell viability of various human cancer cells (including A549, COLO 205, HT-29, Hep3B, HepG2, Huh7, and PCL5 cells) were investigated. The results indicate that compound 2 has a strong inhibitory effect on cell growth in human colorectal carcinoma cells (COLO 205 cells and HT-29 cells).

Metal alloys such as Mg2Ni and TiFe can absorb and store H-2 to form metal hydrides. The alloys are frequently prepared by grinding the metal ingredients together. In this work, a solvothermal synthesis was taken to prepare the Mg-Ni/C nanocomposite from vitamin C, magnesium acetate, and nickel acetate, using ethylene glycol as solvent and reductant. Without adding Pd as nucleating agent, it is proposed to obtain Mg-Ni alloys by reduction and carbon nanoparticles by carbonization. XRD analysis shows that Mg2Ni and Mg-Ni-2 have been formed as nanocomposite with carbon. After calcination in vacuum at 500 degrees C for 1 h, the Mg-Ni/C nanocomposite showed enhanced magnetism. XRD results give peaks of Ni and MgO, indicative of phase separation and Mg oxidation. In conclusion, it is feasible to synthesize Mg-Ni/C or other carbon-containing hydrogen storage composites using the solvothermal method. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

We report fabrication of compacted Bi0.5Sb1.5Te3 composites by adding 1wt% of carbon spheres in the hydrothermal synthesis. The processing parameter of sintering temperature is investigated in order to optimize the thermoelectric power factor of pressed Bi0.5Sb1.5Te3 composites. As a result, we find that the composite sintered at 360°C shows the best power factor performance among the composites and has a largest power factor of 15.4μW/cmK2 at 205K and 13.5μW/cmK2 at 290K. When compared with the samples without addition of carbon sphere in the hydrothermal synthesis, the composites sintered at 340°C and 360°C both surpass the largest power factor of 12.1μW/cmK2 at 280K and 11.9μW/cmK2 at 290K for the 340°C-sintered counterpart.

Carbon spheres (CSs) have been an important subject of research in recent years. Catalytic chemical vapor deposition (CCVD) was carried out in this work to synthesize solid-core CSs at mild temperatures from 720 to 810 degrees C. Non-magnetic metal complexes of La, Nb, and Ti, dispersed on porous kaolin support, were tried out as catalyst. X-ray diffraction patterns revealed the graphitic structures of CSs. TEM analysis showed no encapsulated transition-metal nanoparticles inside the CSs. It was found by Raman spectra that the La catalyst resulted in CSs with higher graphitization. To examine the potential applications of CSs to the fields such as catalysis, electrochemistry, and electronic device, values of the thermal and electrical conductivity of the prepared CSs using different catalysts were measured and found to be comparable to those of the commercial carbon black. (C) 2011 Elsevier B.V. All rights reserved.

Previous research indicates that cantharidin, norcantharidin and their analogues exhibit anticancer activity due to their inhibition of cancer cell lines such as HL60, HT29 and L1210. The anticancer activities of cantharidin, norcantharidin and their analogues involve the suppression of serine/threonine protein phosphatases (PPs) activity. However, cantharidin is not suitable for cancer therapy because of its high cytotoxicity in vitro (IC(50) = 21 microM in primary cultured rat hepatocytes). In this study, synthetic cantharidin analogues with a structure of aminothiazole compounds 3-9 and a structure of anhydride compounds 10-12 were screened for anticancer activities and cytotoxic effects on human hepatocellular carcinoma cell (HCC) lines HepG2, Sk-Hep1, and primary cultured rat hepatocytes. Experimental results indicated that compounds 3-9 did not perform as expected with regard to anticancer activity and exhibited lower cytotoxicity. Compound 10 promoted apoptosis in HepG2 (IC(50) = 62 microM) and SK-Hep1(IC(50) = 151 microM) cell lines. Compounds 11 and 12 had anticancer potential similar to that of compound 10. After treatment with compounds 3-12, primary cultured rat hepatocytes exhibited no cytotoxicity (IC(50) > 200 microM). By investigating the structure-activity relationship (SAR) of these analogues as a whole, this study suggests that the anhydride ether oxygen such as in cantharidin, norcantharidin and compounds 10-12 may be correlated with HCC survival suppression. The results further suggest that the elimination of bridging ether oxygen on the ring, such as in compounds 10-12, can decrease cytotoxicity.

We have grown spiral carbon nanofibers containing Pd metal clusters using the Pd2(dba)3 catalyzed decomposition of gaseous acetylene on molecular sieves (AlPO4-5) support. The microstructure and composition of the spiral carbon nanofibers were examined by the powder X-ray diffractometer and transmission electron microscope. The conductivity of the mat in the temperature range from 14 to 250 K could be described by the form of exp[−(T−1/4)]. The thermopower shows a remarkably linear behavior down to 40 K, reminiscent of some conducting polymers. The sign change of the thermopower suggests there exists more than one type of charge carrier, which could be ascribed to the different types of nanotube with various sizes of radius. The transport behavior of spiral carbon nanofibers containing Pd metal clusters will be discussed in the framework of the heterogeneous model.

Novel self-organized carbon nanoropes consisting of three helically coiled multi-wall nanotubes with a remarkable constant pitch over several microns were grown by the lanthanide oxide-catalyzed decomposition of gaseous acetylene on aluminophosphate (AlPO4-5) support. Direct characterization by the stereo transmission electron microscope and scanning electron microscope has convincingly shown that these three strands entwine with each other helically, which are presumably kept together by both the spontaneous curvature and van der Waals (vdW) attraction.

The reaction of Os 3 (CO) 10 (CNR)(NCMe) ( 1 ) with HCl was studied and this system was found to be a good model for observing the fine-tuning of site-selective protonation in metal complexes. Three products including the protonated species [(ε-H)Os 3 (CO) 10 (CNR)(NCMe)] + Cl − ( 2 ), the bridging aminocarbyne complex (µ-Cl)Os 3 (CO) 10 (µ 2 -C = NHR) ( 3 ), and the hydrido derivative (ε-H)Os 3 Cl(CO) 10 (CNR) ( 4 ) were obtained for the reaction. The site of protonation, either on the Os center or on the nitrogen atom of coordinated isocyanide, was tuned in a sensitive manner by the nature of the coordinated isocyanides, the polarity of the solvents, and the strengths of the acids, leading to different product distributions. The more electron withdrawing isocyanides (CNCH 2 Ph, CNPh) favor the formation of the aminocarbyne complex 3 . In a nonpolar solvent like cyclohexane the reaction afforded 3 as the main product. Furthermore, complex 2 was converted to (ε-H)Os 3 (CO) 10 (ε 2 -CONHR) ( 5 ) upon hydrolysis, in which the coordinated isocyanide was transformed to a carboxamido group. This was verified by obtaining the deuterated species (ε-H)Os 3 (CO) 10 (ε 2 -CONDPr) when [(ε-H)Os 3 (CO) 10 (CNPr)(NCMe)] + Cl − ( 2a ) was treated with D 2 O in THF. The molecular structures of (µ 2 -Cl)Os 3 (CO) 10 (µ 2 -C = NHCH 2 Ph) ( 3b ) and (ε-H)Os 3 Cl(CO) 10 (CNPr) ( 4a ) were determined by X-ray diffraction analyses. Complex 3b contains both bridging chloride and bridging aminocarbyne groups, whereas 4a contains a terminal chloride, a terminal isocyanide and a bridging hydride.

Reactions of Cp*WRu2(CCPh)(CO)8 (1a) with excess Cp*W(CO)3H, Cp* = C5Me5, affords a carbido−alkylidyne cluster Cp*3W3Ru2(μ4-C)(μ3-CPh)(CO)9 (5) alone with three byproducts, which are identified as hydride cluster Cp*WRu3(μ-H)3(CO)11 (2), vinylidene cluster Cp*2W2Ru2(CCHPh)(CO)9 (4), and a pentanuclear oxo−carbido cluster Cp*2W2(O)Ru3(μ5-C)(CO)11 (3). In contrast, the respective condensation using tert-butyl derivative Cp*WRu2(CCBut)(CO)8 (1b) gives an acetylide cluster Cp*3W3Ru2(μ3-CCBut)(CO)9 (6). The X-ray structural determinations of 5 and 6 reveals the existence of an edge-bridged tetrahedral core, in which the butterfly crater is occupied by a μ4-carbide in 5 or a quadruply bridging CO ligand in 6. A plausible mechanism leading to the formation of these two cluster compounds is also presented.

The hexaruthenium cluster compound Ru6(μ3-H)(CO)15[C5H4(SiMe3)] (2), possessing two μ4-η2-CO ligands and with the Ru[C5H4(SiMe3)] fragment located at the apex of the central tetrahedral framework, was prepared in low yield by refluxing a toluene solution of C5H5(SiMe3) with excess Ru3(CO)12. This unique complex was characterized by spectroscopic methods and by X-ray structural analysis. The possible mechanism leading to its formation is discussed.

Combination of mononuclear complexes Cp*W(CO)(3)(CCR) (Cp* = C5Me5; R = Ph, Bu-n, CH2OMe, CH2OPh) with the triosmium cluster Os-3(CO)(10)(NCMe)(2) in toluene affords two isomeric acetylide cluster compounds a and b, which possess the formula Cp*WOs3(CCR)(CO)(11) (R = Ph (1), Bu-n (2), CH2OMe (3), CH2OPh (4)). Isomers a and b undergo reversible interconversion by relocating the Cp*W(CO)(2) fragment between the hinge and wingtip positions upon heating in solution. Their reactivities vs the substituents on the acetylide ligand are also investigated and compared. Thus, thermolysis of la furnishes the carbido-alkylidyne cluster Cp*WOs3(mu(4)-C)(mu-CPh)(CO)(10) (5) through reversible scission of the C-C bond induced by elimination of CO. By contrast, heating of 2 or 3 gives an isomeric mixture of the carbido-vinylidene clusters CP*WOs3(mu(4)-C)(mu-H)(mu-CCHR')(CO)(9) (R' = Pr-n (6), OMe (7)) through a subsequent C-H activation. The CH2OPh isomers 4 readily eliminate two CO ligands to give two isomeric carbido-benzofuryl clusters CP*WOs3(mu(4)-C)(mu-H)(2)(mu-C8H6O)-(CO)(9) (9 and 10), in which the furyl fragments are produced through subsequent orthometalation involving the phenyl group, C-C bond formation, and H migration. Hydrogenation of 3 produces the dihydrido-acetylide cluster Cp*WOs3(mu-H)(2)(CCCH2OMe)(CO)(10) (11) and the carbido-allkylidyne cluster Cp*WOs3(mu(4)-C)(mu-H)(2)(mu-CCH2OMe)(CO)(9) (13) subsequently. The acetylide cluster II converts to the tetrahedral alkylidyne complex Cp*WOs3(mu(3)-CCH2CH2OMe)(CO)(11) (12) via addition of a CO ligand, whereas the alkylidyne cluster 13 isomerizes upon further heating in solution, giving the alkenyl cluster Cp*WOs3(mu(4)-C)(mu-H)(2)(mu-CHCHOMe)(CO)(9) (14) via a 1,2-H shift. Spectroscopic data, X-ray structural analyses, and the possible mechanism leading to the interconversions are presented.