Abstract  Concern with increasing levels of emerging contaminants exists on a global scale. Three commonly observed emerging environmental contaminants: triclosan (2,4,4-trichloro-2'-hydroxydiphenyl ether), a synthetic, broad-spectrum antibacterial agent, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), used in stain- and water-resistant treatments, have become distributed ubiquitously across ecosystems and have been detected in wildlife and humans. MCF-7 BOS human breast cancer cells were used to investigate the potential for cytotoxicity, estrogenicity and anti-estrogenicity of these three compounds at environmentally relevant concentrations using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay (MTS) and the E-SCREEN bioassay. The doses used were 0.002-200 µg ml(-1) for triclosan and 0.03-30 µg ml(-1) for PFOS and PFOA. Quantitative results from the MTS assay revealed no significant cytotoxicity at lower concentrations for any of the test compounds; however, both triclosan and PFOA were cytotoxic at the highest concentrations examined (100-200 and 30 µg ml(-1), respectively), while PFOS showed no significant cytotoxicity at any of the concentrations tested. Positive estrogenic responses (P < 0.05) were elicited from the E-SCREEN at all concentrations examined for triclosan and PFOA and at 30 µg ml(-1) for PFOS. Further, significant anti-estrogenic activity (P < 0.05) was detected for all compounds tested at all concentrations when cells were co-exposed with 10(-9) m 17-β estradiol (E(2)). The overall results demonstrated that triclosan, PFOS and PFOA have estrogenic activities and that co-exposure to contaminants and E(2) produced anti-estrogenic effects. Each of these compounds could provide a source of xenoestrogens to humans and wildlife in the environment. Published 2011. This article is a US Government work and is in the public domain in the USA.

Abstract  Perfluorooctanoate (PFOA) has been detected in surface water all over the world, and little is known of its removal by coagulation in water treatment plants. In this study, polyaluminium chloride (PACl) was used to remove PFOA from surface water, and the effects of coagulant dose, solution pH, temperature, and initial turbidity on the removal of both PFOA and suspended solids (SS) from water were investigated. Since the SS had high sorption affinity for PFOA, most PFOA was adsorbed on the particles and removed via the SS removal in the coagulation process. PFOA concentrations in aqueous phase decreased with increasing initial turbidity and PACl dose, while they increased with increasing solution pH and temperature. Other perfluorinated compounds (PFCs) with different C-F chain lengths and functional groups were also compared with PFOA. It was proved that hydrophobic interaction played an important role in the adsorption of PFOA on the SS. The addition of powdered activated carbon (PAC) before the coagulation process significantly enhanced the removal efficiency of PFOA in water, and the residual PFOA concentrations in water were less than 1 μg/L after the addition of 1-16 mg/L PAC and subsequent coagulation when the initial PFOA concentrations were in the range of 0.5-3 mg/L.

Abstract  Monodisperse gold clusters have been prepared on surfaces in different charge states through soft landing of mass-selected ions. Ligand-stabilized gold clusters were prepared in methanol solution by reduction of chloro(triphenylphosphine)gold(I) with borane tert-butylamine complex in the presence of 1,3-bis(diphenylphosphino)propane. Electrospray ionization was used to introduce the clusters into the gas phase, and mass selection was employed to isolate a single ionic cluster species (Au(11)L(5)(3+), L = 1,3-bis(diphenylphosphino)propane), which was delivered to surfaces at well-controlled kinetic energies. Using in situ time-of-flight secondary ion mass spectrometry (TOF-SIMS), it is demonstrated that the Au(11)L(5)(3+) cluster retains its 3+ charge state when soft landed onto the surface of a 1H,1H,2H,2H-perfluorodecanethiol self-assembled monolayer (FSAM) on gold. In contrast, when deposited onto 16-mercaptohexadecanoic acid (COOH-SAM) and 1-dodecanethiol (HSAM) surfaces on gold, the clusters exhibit larger relative abundances of the 2+ and 1+ charge states, respectively. The kinetics of charge reduction on the FSAM and HSAM surfaces are investigated using in situ Fourier transform ion cyclotron resonance (FT-ICR) SIMS. It is shown that an extremely slow interfacial charge reduction occurs on the FSAM surface while an almost instantaneous neutralization takes place on the surface of the HSAM. Our results demonstrate that the size and charge state of small gold clusters on surfaces, both of which exert a dramatic influence on their chemical and physical properties, may be tuned through soft landing of mass-selected ions onto carefully selected substrates.

Abstract  Degradation of fluorotelomer alcohols (FTOHs) was recognized as an additional source of perfluorocarboxylic acids (PFCAs). Quantification of FTOHs and their degradation products can help shed light on the sources and fates of PFCAs in the environment. In this study, an analytical method was developed for the determination of 6:2 and 8:2 FTOHs, and their degradation products of poly- and perfluorinated acids, including fluorotelomer saturated and unsaturated carboxylic acids (FTCAs and FTUCAs), secondary polyfluorinated alcohols and PFCAs in biosolids-amended soils and plants using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The extract efficiencies of different methods including ethyl acetate and methanol (MeOH) for FTOHs and acetonitrile, MeOH, methyl tert-butyl ether (MTBE), NaOH-MeOH and NaOH-MTBE for poly- and perfluorinated acids were tested. The results showed that 6:2 and 8:2 FTOHs and their degradation products could be simultaneously and satisfactorily extracted by MeOH, cleaned up by Envi-Carb graphitized carbon and solid phase extraction, respectively, and determined by UPLC-MS/MS separately. NaOH in the extractant caused the conversion of 6:2 FTCA and 8:2 FTCA into the corresponding FTUCAs. The selected methods have matrix recoveries ranged from 52% to 102%, and detection limits of 0.01-0.46ng/g dry weight for FTOHs and their degradation products in soil and plant. The optimized method was applied successfully to quantify FTOHs and their degradation products in two biosolids-amended soils and plants. The total concentrations of FTOHs in the soils were 44.1±5.8 and 82.6±7.1ng/g, and in plants tissues 3.58±0.25 and 8.33±0.66ng/g. The total concentrations of poly- and perfluorinated acids in the soils were 168.0±13.2 and 349.6±11.2ng/g, and in plants tissues 78.0±6.4 and 75.5±5.3ng/g.

Abstract  Two perfluorinated surfactants, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were evaluated for their toxicity to the aquatic midge, Chironomus tentans. Impetus for this laboratory study originated from a 10-d, in situ field assessment in which C. tentans was exposed to PFOS at concentrations ranging from 300 to 30,000 microg/L. No midges survived these exposures. Midge survival in a preliminary, acute 10-d laboratory test with nominal PFOS concentrations ranging from 0.1 to 100,000 microg/L showed similar toxicity with respect to survival (median lethal concentration [LC50], 45.2 microg/L) and growth (median effective concentration [EC50], 27.4 microg/L). A parallel test using PFOA indicated no significant impacts on survival or growth. A definitive 10-d assay with PFOS concentrations ranging from 1 to 150 microg/L produced an EC50 for growth (87.2+/-11.6 microg/L) of the same order of magnitude as that in the preliminary findings. The same was not true for survival, however, with the LC50 falling outside the range of test concentrations. To further investigate the sensitivity of C. tentans to PFOS, we conducted a chronic life-cycle test using a nominal concentration range of 1 to 100 microg/L. Three of the four endpoints measured-survival, growth, and emergence-were significantly affected, with EC50 values of 92.2+/-3.1, 93.8+/-2.6, and 94.5+/-3.2 microg/L, respectively. Reproduction was not affected by those PFOS concentrations at which females emerged. The results of the present study indicate that PFOS toxicity thresholds for C. tentans are as much as three orders of magnitude lower than those reported for other aquatic organisms but, at present, are approximately two orders of magnitude higher than those concentrations typically observed in aquatic environments.

Abstract  Background: Perfluorooctanoate (PFOA) is a synthetic chemical widely detectable in blood of nonoccupationally exposed persons. Its human health effects are not well-characterized. Methods: We conducted a mortality study in a cohort of 3993 employees of an ammonium perfluorooctanoate (APFO) manufacturing facility. APFO rapidly dissociates to PFOA in blood. We estimated standardized mortality ratios (SMRs) compared with the general population, and fit time-dependent Cox regression models to estimate the risks using an internal-cohort referent population. A priori diseases of interest were liver, pancreatic, prostate, and testicular cancer; cirrhosis of the liver; and cerebrovascular disease. Results: APFO exposure was not associated with liver, pancreatic or testicular cancer or with cirrhosis of the liver. SMRs (95% CI) for prostate cancer with no, probable and definite exposure strata were 0.4 (0.1–0.9), 0.9 (0.4–1.8), and 2.1 (0.4–6.1), respectively, and for cerebrovascular disease 0.5 (0.3–0.8), 0.7 (0.4–1.1), and 1.6 (0.5–3.7), respectively. The diabetes SMR for probable exposure was 2.0 (1.0–3.2). Compared with an internal referent population of nonexposed workers, moderate or high exposures to ammonium perfluorooctanoate were positively associated with prostate cancer (HR = 3.0 [0.9–9.7] and 6.6 [1.1–37.7], respectively) and with cerebrovascular disease (1.8 [0.9–3.1] and 4.6 [1.3–17.0], respectively). Diabetes was associated with moderate exposure 3.7 (1.4–10.1); no deaths from diabetes occurred in workers with high exposure. Conclusion: We did not observe ammonium perfluorooctanoate exposure to be associated with liver, pancreatic, and testicular cancer or cirrhosis of the liver. Exposure was associated (albeit inconsistently) with prostate cancer, cerebrovascular disease, and diabetes.

Abstract  The aerobic biodegradation of [1,2-(14)C] 6:2 FTOH [F(CF(2))(6)(14)CH(2)(14)CH(2)OH] in a flow-through soil incubation system is described. Soil samples dosed with [1,2-(14)C] 6:2 FTOH were analyzed by liquid scintillation counting, LC/ARC (liquid chromatography/accurate radioisotope counting), LC/MS/MS, and thermal combustion to account for 6:2 FTOH and its transformation products over 84 d. Half of the [1,2-(14)C] 6:2 FTOH disappeared from soil in 1.3 d, undergoing simultaneous microbial degradation and partitioning of volatile transformation product(s) and the 6:2 FTOH precursor into the air phase. The overall (14)C (radioactivity) mass balance in live and sterile treatments was 77-87% over 84-d incubation. In the live test system, 36% of total (14)C dosed was captured in the airflow (headspace), 25% as soil-bound residues recovered via thermal combustion, and 16% as soil extractable. After 84 d, [(14)C] 5:2 sFTOH [F(CF(2))(5)CH(OH)(14)CH(3)] was the dominant transformation product with 16% molar yield and primarily detected in the airflow. The airflow also contained [1,2-(14)C] 6:2 FTOH and (14)CO(2) at 14% and 6% of total (14)C dosed, respectively. The other significant stable transformation products, all detected in soil, were 5:3 acid [F(CF(2))(5)CH(2)CH(2)COOH, 12%], PFHxA [F(CF(2))(5)COOH, 4.5%] and PFPeA [F(CF(2))(4)COOH, 4.2%]. Soil-bound residues as well as conjugates between fluorinated transformation products and dissolved soil components were only observed in the live test system and absent in the sterile soil, suggesting that such binding and complexation are microbially or enzymatically driven processes. At day 84, 5:3 acid is postulated to be the major transformation product in soil-bound residues, which may not be available for further biodegradation in soil environment.

Abstract  The intent of this account is to provide a focused overview of recent developments in aryl radical chemistry, especially extensions and applications of the Meerwein arylation and the Gomberg-Bachmann reaction. Although most of the reactions and methods described were discovered on the basis of earlier findings made by our group or logically depend on newly discovered reactivities or mechanistic principles, the rapid evolution of radical chemistry can nevertheless be traced back to the behavior of the natural product stephanosporin, which is capable of liberating 2-chloro-4-nitrophenol via an aryl radical intermediate.

1 Introduction to Aryl Radical Chemistry

2 Stephanosporin

3 Low-Temperature Radical Initiators That Generate Aryl Radicals

4 Alkene Functionalizations

4.1 Carboamination

4.1.1 Carbodiazenylation Reactions

4.1.2 Carbonitrosation Reactions

4.2 Carbooxygenation

4.3 Carbofluorination

4.4 Allylation and Vinylation

4.5 Reductive Arylation and Labelling with Fluorine-18

4.6 Cascade Reactions

5 Arene Functionalizations

5.1 Arylations with Aryldiazonium Salts

5.2 Arylations with Arylhydrazines

5.3 Acid-and Base-Induced Arylations

6 Summary and Outlook

Abstract  The 6:2 FTOH [F(CF(2))(6)CH(2)CH(2)OH] is a major raw material being used to replace 8:2 FTOH [F(CF(2))(8)CH(2)CH(2)OH] to make FTOH-based products for industrial and consumer applications. A novel aerobic sediment experimental system containing 20 g wet sediment and 30 mL aqueous solution was developed to study 6:2 FTOH biotransformation in river sediment. 6:2 FTOH was dosed into the sediment to follow its biotransformation and to analyze transformation products over 100 d. The primary 6:2 FTOH biotransformation in the aerobic sediment system was rapid (T(1/2)<2d). 5:3 acid [F(CF(2))(5)CH(2)CH(2)COOH] was observed as the predominant polyfluorinated acid on day 100 (22.4 mol%), higher than the sum of perfluoropentanoic acid (10.4 mol%), perfluorohexanoic acid (8.4 mol%), and perfluorobutanoic acid (1.5 mol%). Perfluoroheptanoic acid was not observed during 6:2 FTOH biotransformation. The 5:3 acid can be further degraded to 4:3 acid [F(CF(2))(4)CH(2)CH(2)COOH, 2.7 mol%]. This suggests that microbes in the river sediment selectively degraded 6:2 FTOH more toward 5:3 and 4:3 acids compared with soil. Most of the observed 5:3 acid formed bound residues with sediment organic components and can only be quantitatively recovered by post-treatment with NaOH and ENVI-Carb™ carbon. The 6:2 FTCA [F(CF(2))(6)CH(2)COOH], 6:2 FTUCA [F(CF(2))(5)CF=CHCOOH], 5:2 ketone [F(CF(2))(5)C(O)CH(3)], and 5:2 sFTOH [F(CF(2))(5)CH(OH)CH(3)] were major transient intermediates during 6:2 FTOH biotransformation in the sediment system. These results suggest that if 6:2 FTOH or 6:2 FTOH-based materials were released to the river or marine sediment, poly- and per-fluorinated carboxylates could be produced.

Abstract  The polyfluorinated carboxylic acids 5:3 acid (C(5)F(11)CH(2)CH(2)CO(2)H) and 7:3 acid (C(7)F(15)CH(2)CH(2)CO(2)H) are major products from 6:2 FTOH (C(6)F(13)CH(2)CH(2)OH) and 8:2 FTOH (C(8)F(17)CH(2)CH(2)OH) aerobic biotransformation, respectively. The 5:3 and 7:3 acids were dosed into domestic WWTP activated sludge for 90 d to determine their biodegradability. The 7:3 acid aerobic biodegradability was low, only 1.7 mol% conversion to perfluoroheptanoic acid (PFHpA), whereas no transformation was observed previously in soil. In stark contrast, 5:3 acid aerobic biodegradability was enhanced 10 times in activated sludge compared to soil. The 5:3 acid was not activated by acyl CoEnzyme A (CoA) synthetase, a key step required for further α- or ß-oxidation. Instead, 5:3 acid was directly converted to 4:3 acid (C(4)F(9)CH(2)CH(2)CO(2)H, 14.2 mol%) and 3:3 acid (C(3)F(7)CH(2)CH(2)CO(2)H, 0.9 mol%) via "one-carbon removal pathways". The 5:3 acid biotransformation also yielded perfluoropentanoic acid (PFPeA, 5.9 mol%) and perfluorobutanoic acid (PFBA, 0.8 mol%). This is the first report to identify key biotransformation intermediates which demonstrate novel one-carbon removal pathways with sequential removal of CF(2) groups. Identified biotransformation intermediates (10.2 mol% in sum) were 5:3 Uacid, α-OH 5:3 acid, 5:2 acid, and 5:2 Uacid. The 5:2 Uacid and 5:2 acid are novel intermediates identified for the first time which confirm the proposed pathways. In the biodegradation pathways, the genesis of the one carbon removal is CO(2) elimination from α-OH 5:3 acid. These results suggest that there are enzymatic mechanisms available in the environment that can lead to 6:2 FTOH and 5:3 acid mineralization. The dehydrogenation from 5:3 acid to 5:3 Uacid was the rate-limiting enzymatic step for 5:3 acid conversion to 4:3 acid.

Abstract  Polyethylene glycol (PEG) chains covalently linked to phospholipids are often used in the preparation of lipid or even polymer colloidal particles to avoid recognition and clearance by the reticuloendothelial system and to increase their plasmatic half-life. To the best of our knowledge, no direct method allows yet to quantify these pegylated phospholipids. The aim of this work was to develop a method for the quantification of a typical pegylated phospholipid, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000], DSPE-PEG2000, associated to polymeric microcapsules of perfluorooctyl bromide (PFOB). Reverse phase high-performance liquid chromatography (HPLC) was used, coupled with a corona charged aerosol detection (HPLC-CAD). Calibrations standards consisted of plain microcapsules and pegylated phospholipids (DSPE-PEG2000) in the concentration range of 2.23-21.36 mu g/mL (0.22-2.14 mu g injected). Calibration curve was evaluated with two different model, linear and power model. The power model describes experimental values better than the linear model, for pegylated phospholipids with the CAD detector. The correlation coefficient for the power model was 0.996, and limits of detection and quantification obtained were 33 and 100 ng, respectively. This method proved to be selective and sensitive; the accuracy of the method ranged from 90 to 115% and the relative standard deviation was <= 5.3%. Pegylated phospholipids associated to microcapsules, as well as the phospholipids and total phospholipids in the suspensions were successfully quantified in three different preparations of microcapsules. (C) 2008 Elsevier B.V. All rights reserved.

Abstract  Biotransformation of 6:2 FTOH [F(CF2)6CH2CH2OH] by the white-rot fungus, Phanerochaete chrysosporium, was investigated in laboratory studies. 6:2 FTOH is a raw material increasingly being used to replace products that can lead to long-chain perfluoroalkyl carboxylic acids (PFCAs, ≥ 8 carbons). During a product's life cycle and after final disposal, 6:2 FTOH-derived compounds may be released into the environment and potentially biotransformed. In this study, P. chrysosporium transformed 6:2 FTOH to perfluorocarboxylic acids (PFCAs), polyfluorocarboxylic acids, and transient intermediates within 28 days. 5:3 Acid [F(CF2)5CH2CH2COOH] was the most abundant transformation product, accounting for 32-43 mol % of initially applied 6:2 FTOH in cultures supplemented with lignocellulosic powder, yeast extract, cellulose, and glucose. PFCAs, including perfluoropentanoic (PFPeA) and perfluorohexanoic (PFHxA) acids, accounted for 5.9 mol % after 28-day incubation. Furthermore, four new transformation products as 6:2 FTOH conjugates or 5:3 acid analogues were structurally confirmed. These results demonstrate that P. chrysosporium has the necessary biochemical mechanisms to drive 6:2 FTOH biotransformation pathways toward more degradable polyfluoroalkylcarboxylic acids, such as 5:3 acid, with lower PFCA yields compared to aerobic soil, sludge, and microbial consortia. Since bacteria and fungi appear to contribute differently toward the environmental loading of FTOH-derived PFCAs and polyfluorocarboxylic acids, wood-rotting fungi should be evaluated as potential candidates for the bioremediation of wastewater and groundwater contaminated with fluoroalkyl substances.

Abstract  Sediment microbial communities are responsible for many chemical biotransformation processes in the aquatic environment and play a critical role in various ecosystems and biogeochemical cycling. However, the impact of polyfluoroalkyl substances on sediment microbial communities remains unclear. These substances are increasingly being used in consumer and industrial products to replace environmentally persistent perfluoroalkyl substances. In this study, we investigated the effects of low (5mg/L) and high (15mg/L) doses of 6:2 fluorotelomer alcohol [6:2 FTOH, F(CF2)6CH2CH2OH] on the structure of a sediment microbial community. 6:2 FTOH biotransformation was rapid in the sediment mixture with a half-life <3days, regardless of the initial doses. After 28days, major products produced in the high dose condition included 28mol% 5:2 sFTOH [F(CF2)5CH(OH)CH3], 9.6mol% 5:3 Acid [F(CF2)5CH2CH2COOH] and 11mol% PFHxA [F(CF2)5COOH], while 73mol% 5:2 sFTOH, 23mol% 5:3 Acid and 26mol% PFHxA were observed in the low dose condition. In the original (control) sediment without 6:2 FTOH dosing, Proteobacteria was the predominant microorganism (18%), followed by Chloroflexi (14%), Verrucomicrobia (13%), Firmicutes (3.4%), Bacterioidetes (2.4%), Actinobacteria (1.7%) and Planctomycetes (1.3%). The presence of 6:2 FTOH and the accumulation of transient transformation products in the sediment exerted selection pressure on the microbial taxonomic distribution and diversity. Our observations indicate that potential 6:2 FTOH degraders and tolerant strains, such as Dokdonella spp., Thauera spp., Albidovulum spp. and Caldanaerovirga spp., existed in the sediment mixture and began to dominate over time. This suggests that these genera might have higher tolerance towards elevated 6:2 FTOH and its transformation products. These findings on the characterization of sediment microbial community stability and dynamics will help predict changes in response to perfluoroalkyl and polyfluoroalkyl substances and also help identify robust microbial strains to degrade polyfluoroalkyl substances in the environment.

Abstract  Water-soluble and blue luminescent graphene fluoroxide quantum dots (GFOQDs) with tunable fluorine coverage and size were effectively synthesized from exfoliated fluorinated graphene (FG) by sacrificing certain fluorine to improved solubility and reaction activity. Morphology investigation indicates that the obtained GFOQDs possess narrow size distribution and the average size is 2.5-3.5 nm. Chemical composition analysis confirms that besides C-F covalent bonds, C-O bonds in the forms of hydroxyl and carbonyl co-exist on the structure of GFOQDs. Moreover, photoluminescence performance research considering the surface state and size has also been conducted, and as anticipated in carbon-based quantum dots the GFOQDs exhibit excitation wavelength-dependent properties. Additionally, rather different from other graphene quantum dots (GQDs) that are often susceptible to pH without additional surface passivation, the GFOQDs themselves are poised to resist pH effects and display stable luminescence in both acid and alkali conditions. These results indicate that our method not only opens up a new avenue to prepare GQDs decorated with fluorine and oxygen, but also can find practical applications in novel GQDs-based devices that require water solubility while keep chemical stability and resistance against pH. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  In this study, we have reported poly(benzimidazole-amide) containing flexible moieties such as ether, fluoro, and siloxane. The poly(benzimidazole-amide) synthesis was carried out by the condensation of 4-(3,4-diaminophenoxy)benzene-1,2-diamine, bis(carboxypropyl)-tetramethyldisiloxane, and 2,2-bis(4-aminophenyl)hexafluoropropane in the presence of polyphosphoric acid at 160?. Afterwards, poly(benzimidazole-amide) was blended with sulfonated polystyrene and 0.1-2wt.% titania nanoparticles-grafted-multi-walled carbon nanotubes for the formation of hybrid proton exchange membranes for fuel cell (poly(benzimidazole-amide)/sulfonated polystyrene/titania nanoparticles-grafted-multi-walled carbon nanotubes) for fuel cell. Inclusion of titania modified multi-walled carbon nanotubes influenced the membrane performance by modifying the microstructure, mechanical properties, as well as water retention and proton conductivity properties of proton exchange membranes (PEM). The hybrid membranes were doped with phosphoric acid before subjecting to various characterizations. Field emission scanning electron microscopic study depicted typical blend morphology in which titania nanoparticles-grafted-multi-walled carbon nanotubes were partially embedded in the matrix and seemed to be pulled out of the matrix surface during fracturing. The phase separated structure was accountable for the water retention and higher proton conductivity. The tensile stress and modulus of acid doped poly(benzimidazole-amide)/sulfonated polystyrene/titania nanoparticles-grafted-multi-walled carbon nanotubes nanocomposites increased from 65.1 to 72.5MPa and 9.5 to 15.2GPa, respectively, with the increasing titania nanoparticles-grafted-multi-walled carbon nanotubes loading (0.1-2wt.%). The glass transition temperature of phosphoric acid doped poly(benzimidazole-amide)/sulfonated polystyrene/titania nanoparticles-grafted-multi-walled carbon nanotubes 0.1-2 membranes increased from 227 to 236C. They also had higher ion exchange capacity of 2.5-3.7mmol/g and proton conductivity of 2.3-3.1S/cm at 80? (higher than perfluorinated Nafion (R) 117 membrane 1.1x10(-1)S/cm). A H-2/O-2 fuel cell using poly(benzimidazole-amide)/sulfonated polystyrene/titania nanoparticles-grafted-multi-walled carbon nanotubes 2 (ion exchange capacity 3.7mmol/g) showed better performance than that of Nafion (R) 117 at 40? and 30% relative humidity.

Abstract  Poly(benzimidazole/ether/siloxane/amide) (PBESA) having siloxane and ether groups in the backbone has been prepared using 4-(3,4-diaminophenoxy)benzene-1,2-diamine, bis(carboxypropy)tetramethyldisiloxane, and 4,4-oxydianiline via polyphosphoric acid processes with heating up to 160 degrees C. The sulfonation of polystyrene (PS-S) was conducted using 98% sulfuric acid. Afterward, a series of hybrid membranes using PBESA/PS-S/silica nanoparticles (SiNPs) have been developed with 0.1-2 wt% nanofiller. Later, the membranes were doped with phosphoric acid and subjected to various characterization techniques. Field emission scanning electron micrographs (FESEMs) showed gyroid-like patterning of nanoporous membranes with uniform ionic pathways. Fine water retention capability and higher proton conductivity of new hybrids, owing to consistent porous membrane structure, were observed. Increasing the amount of nanoparticles (0.1-2 wt%) also enhanced the tensile stress of acid-doped PBESA/PS-S/SiNPs nanocomposites from 64.9 to 68.1 MPa. There existed a relationship between nanofiller loading and thermal stability of the membranes. The glass transition temperature of phosphoric acid-doped PBESA/PS-S/SiNPs nanocomposites increased from 202 to 214 degrees C. The membranes also had fine ion exchange capacity (IEC) of around 2.5-3.7 mmol g(-1). Novel membranes with high IEC value achieved high proton conductivity of 1.26-2.74 S cm(-1) in a wide range of humidity values at 80 degrees C, which was higher than that for perfluorinated Nafion((R)) 117 membrane (1.1 x 10(-1) S cm(-1) at 80 degrees C, 94% relative humidity (RH)). The fuel cell (hydrogen/oxygen) using PBESA/PS-S/SiNPs 2 (IEC 3.7 mmol g(-1)) showed better performance than that of Nafion((R)) 117 at 40 degrees C (30% RH).

Abstract  Novel routes to 2-trifluoromethyl-nicotinic acid derivatives have been developed involving synthesis of the pyridine ring. These pyridyl compounds serve as key intermediates in the manufacture of the recently discovered COMT inhibitor, 3-(5-(3,4-dihydroxy-5-nitrophenyl)-1,2,4-oxadiazol-3-yl)-2-(trifluoromethyl)pyridine 1-oxide.

Abstract  The reaction of 3-pentafluoroethyl-4,5,6,7-tetrafluoro-1-H-indazole [3-(C2F5)IndF4]H with Ag2O or [Cu(CH3CN)4]BF4 leads to the formation of two different types of complexes: a trinuclear {[3-(C2F5)IndF4]Ag}3 complex (1) in the case of silver, and an unprecedented type of pentanuclear complex [Et3NH]{Cu5[3-(C2F5)IndF4]6} (2) in the case of copper. When crystallised from Et2O, appears as a dimer with d(10)-d(10) interactions. When crystallized from toluene, affords the [(toluene)(1)(toluene)] adduct, testifying to its strong π-acid properties. The formation and the aggregation pattern of 1 and 2 can be traced to the extended aromaticity and high electron withdrawing properties of the perfluorinated [3-(C2F5)IndF4](-) indazolate.

Abstract  Fluorine-18 labeled (2S,4S)-4-fluoro-l-proline (cis-[18F]4-FPro) has been reported to be a potential positron emission tomography tracer to study abnormal collagen synthesis occurring in pulmonary fibrosis, osteosarcomas, mammary and colon carcinomas. In this paper, we report the stereospecific radiofluorination of (2S,4R)-N-tert-butoxycarbonyl-4-(p-toluenesulfonyloxy) proline methyl ester (at 110 degrees C) to produce diastereomerically pure cis-[18F]4-FPro in 38% radiochemical yield at the end of a 90-min synthesis. Investigation of the effect of temperature on the stereospecificity of nucleophilic fluorination showed that diasteriomerically pure cis-[18F]4-FPro or trans-[18F]4-FPro was produced at lower temperatures (85 degrees C110 degrees C) during the fluorination of (2S,4R) or (2S,4S) precursors, respectively. However, at higher temperatures (130 degrees C145 degrees C), fluorination of (2S,4R) precursor produced a mixture of cis-[18F]4-FPro and trans-[18F]4-FPro diastereomers with cis-[18F]4-FPro as the predominant isomer. Hydrolysis of the purified fluorinated intermediate was carried out either in one step, using 2 m triflic acid at 145 degrees C for 10 min, or in two steps where the intermediate was heated in 1 m HCl at 110 degrees C for 10 min followed by stirring at room temperature in 1 N NaOH for 5 min. The aqueous hydrolysis mixture was loaded onto an anion exchange column (acetate form for one-step hydrolysis) or an ion retardation column (two-step hydrolysis) followed by a C18 Sep-Pak (R) (Waters Corporation, Milford, MA, USA). Pure cis-[18F]4-FPro was then eluted with sterile water. We also report that epimerization of cis-[18F]4-FPro occurs during the two-step hydrolysis (H+ followed by OH-) of the intermediate, resulting in 5 +/- 3% trans-[18F]4-FPro, whereas the one-step acid hydrolysis yielded pure cis-[18F]4-FPro in the final product. Copyright (C) 2011 John Wiley & Sons, Ltd.

Abstract  Synthesis and characterization of a new type of Lewis acid, rare earth metal perfluorooctanoate, as well as the recent development of multicomponent condensation reactions catalyzed by rare earth metal perfluorooctanoate has been introduced.

1 Introduction and Background

2 Synthesis and Characterization of Rare Earth Perfluorooctanoate

2.1 Synthesis of Rare Earth Perfluorooctanoate

2.2 Characterization of Rare Earth Perfluorooctanoate

3 RE(PFO)(3) in Organic Solvent

3.1 One-Pot Mannich Reaction

3.2 Condensations of Indole with Carbonyl Compounds

3.3 One-Pot Synthesis of Benzopyran Derivatives

3.4 One-Pot Synthesis of 2-Amino-3-Cyanopyridine Derivatives 4 RE(PFO)(3) in Water

4.1 Doebner Reaction

4.2 Synthesis of Homoallylic Alcohols and Amines 5 RE(PFO)(3) under Solvent-Free Conditions

5.1 Synthesis of alpha-Aminophosphonates

5.2 One-Pot Synthesis of Substituted Pyrazoles

5.3 A Revisit to the Hantzsch Reaction

5.4 One-Pot Fluorous Biginelli Reaction 6 Summary

Abstract  The reaction of 1,2-bis(halomercurio)tetrafluorobenzene (halide = chloride (3) or bromide (4)) with the corresponding indium(I) halide in THF results in spontaneous ring closure and formation of the tetrakis(THF) adducts of 9,10-dichloro-9,10-dihydro-9,10-diindaoctafluoroanthracene (5) and 9,10-dibromo-9,10-dihydro-9,10-diindaoctafluoroanthracene (6), respectively. Diindacycle 6 can also be prepared by reaction of indium(I) bromide with trimeric perfluoro-o-phenylenemercury in refluxing toluene, followed by treatment with THF. Upon addition of pyridine, the ligated THF molecules of 6 are readily displaced and 9,10-dibromo-9,10-dihydro-9,10-diindaoctafluoroanthracene tetrakis(pyridine) (7) is obtained. Compounds 5-7 have been characterized by H-1, C-13, and F-19 NMR spectroscopy, MSCI, and elemental analysis, and their molecular structure has been determined by single-crystal X-ray analysis. All compounds crystallize in monoclinic space groups. Two modifications of compound 6 have been analyzed. 5: space group P2(1)/c with a = 9.686(1) Angstrom, b = 11.071(1) Angstrom, c = 15.725(2) Angstrom, beta = 105.55(1)degrees, V = 1624.5(3) Angstrom(3), and Z = 2. 6: space group P2(1)/c with a = 9.636(1) Angstrom, b = 11.129(1) Angstrom, c = 16.029(2) Angstrom, beta = 104.40(1)degrees, V = 1664.9(3) Angstrom(3), and Z = 2; space group P2(1)/c with a = 10.258(1) Angstrom, b = 13.926(1) Angstrom, c = 11.892(2) Angstrom, beta = 97.86(1)degrees, V = 1682.8(2) Angstrom(3), Z = 2. 7. space group P2(1)/c with a = 17.632(2) Angstrom, b = 15.010(1) Angstrom, c = 14.562(1) Angstrom, beta = 101.72(1)degrees, V = 3773.6(6) Angstrom(3), and Z = 4. The perfluorination of the phenylene rings in 5-7 has a consequent effect on the Lewis acidity of the indium centers which is reflected by the relatively short O-In and N-In dative bond distances.

Abstract  Polyfluoroaromatic ketones Ar(F)COAlk and Ar(F)COPh (Ar(F) = C(6)F(5), 3- and 4-F(3)CC(6)F(4), 4-NCC(6)F(4), 4-EtOCOC(6)F(4), C(5)F(4)N, nonafluoroindan-5-yl; Alk = Me, Et, i-Pr, t-Bu) were synthesized by reactions of polyfluoroarylzinc compounds with acyl chlorides in the presence of CuCl.

Abstract  The effect of the form of 10 types of quaternary ammonium ions (Q(+))for the phase separation phenomenon, which accompanies a charge neutralization with perfluorooctanoate ion (PFOA(-)) and Q(+), was studied, The separated phase using the spherical form of Q(+) (i.e., [4 . 4 . 4 . 4], [3 . 3 . 5 . 5], [3 . 3 . 3 . 7], and [2 . 2 . 6 . 6], where the numbers in square brackets represent the carbon numbers of four kinds of straight alkyl chains which were directly bonded to the nitrogen atom) was in the liquid state, On the other hand, the separated phase using the rod form ([2 . 2 . 2 . 10] and [1 . 1 . 1 . 13]) was in the solid state. The volume, specific gravity, and water content of the liquid-separated phase using [3 . 3 . 5 . 5] were 116 mu l, 1.27, and 6.98%, respectively, under the following experimental conditions: [Q(+)](T) = 2.30 x 10(-2) mol dm(-3), [PFOA(-)](T) = 5.75 x 10(-3) mol dm(-3), and 25 degrees C, This liquid phase was stable to physical changes such as Qi total concentration and temperature, compared with three other types of Q(+) ([4 . 4 . 4 . 4], [3 . 3 . 3 . 7], and [2 . 2 . 6 . 6]), which formed similar liquid-separated phases. (C) 1997 Academic Press

Abstract  An efficient approach for the synthesis of 3-(polyfluoroacyl)pyruvaldehydes dimethyl acetals (1,1-dimethoxy-4polyfluoroalkyl-butan-2,4-dions) from 1,1-dimethoxyacetone and polyfluorinated carboxylic acid esters has been developed. The procedure includes the Claisen type condensation of the starting materials by means of calcium hydride in methanol, followed by isolation of copper complexes of the corresponding diketones and their destroying with disodium EDTA. A simple synthesis of 5(3)-(polyfluoroalkyl)-1H-pyrazole-3(5)-carbaldehydes and their acetals is also presented.

Abstract  A novel amphiphilic diarylethene with two cholic acid groups, 1,2-bis[2-methyl-5-[3-(1,2,3-triazole) methyl-5-cholic acid-3-thienyl]perfluorocyclopentene, has been successfully synthesized by click reaction for the first time and its photochromic, fluorescence, and electrochemistry properties were systematically investigated. This new compound showed good hydrophilia in methanol/water binary solution (v/v, 1:19). It exhibited photochromism with the notable color change from colorless to red and good fatigue -resistance by photoirradiation. Further study indicated that it also has excellent fluorescence switching property in methanol/water binary solution. (C) 2016 Elsevier Ltd. All rights reserved.