http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Wed, 19 Jun 2013 12:18:07 +0000 http://www.hindawi.com/journals/chem/2013/108318/ The present paper introduces a simple and efficient method for the synthesis of substituted benzimidazoles by heterocyclization of different o-phenylenediamines and substituted aromatic carboxylic acid/aldehyde in the presence of zirconyl nitrate as catalyst in ethanol under reflux, which produced excellent yield of corresponding benzimidazoles in a short reaction time with reusability of catalyst. Pratapsinha B. Gorepatil, Yogesh D. Mane, and Vilas S. Ingle Copyright © 2013 Pratapsinha B. Gorepatil et al. All rights reserved. Wed, 19 Jun 2013 11:50:00 +0000 http://www.hindawi.com/journals/chem/2013/519415/ This paper describes a convenient synthesis of 1,4-dideoxy-1,4-imino-D-ribitol (DRB) from D-ribose. L-Lyxonolactone, a key intermediate in this synthesis, was prepared by base-promoted hydrolysis of a 5-chlorinated D-ribonolactone derivative with inversion of configuration at the C-4 position. Cyclization of the generated dimesylated L-lyxitol with benzylamine proceeded with another configurational inversion at C-4 to afford the D-ribo-configured pyrrolidine system, which upon deprotection gave DRB. Makoto Oba, Shoi Kawaji, Hironobu Kushima, Takanori Sano, and Kozaburo Nishiyama Copyright © 2013 Makoto Oba et al. All rights reserved. Tue, 18 Jun 2013 09:18:19 +0000 http://www.hindawi.com/journals/chem/2013/819462/ Some new fluorine substituted heterocyclic nitrogen systems 2–17 have been synthesized from ring closure reactions of substituted p-amino salicylic acids (PAS). The Schiffs base of PAS was cyclized with chloroacetyl chloride and mercaptoacetic acid to give azetidinone 2, thiazolidinone 3, and spiro-fluoroindolothiazoline-dione 10. However, PAS when reacted directly with 4-fluorobenzoyl chloride and 5-oxazolinone yielded derivatives 4, 5, and 7. Aminomethylation of PAS using formaldehyde and piperidine or piperazine formed N-alkyl and N,N′-dialkyl derivatives (11 and 12 respectively) upon fluorinated benzoylation gave compounds 13 and 14. Similarly, treatment of PAS with thiosemicarbazide 15 and subsequent cyclization with diethyl oxalate yielded the fluorinated heterocycle 17. The structures of the fluorinated heterocyclic systems have been established on the basis of elemental analysis, 1H NMR, 13C NMR, and MS spectral data. Some of the targets exhibited a high inhibition towards Mycobacterium strain with favorable log P values. Mohammed Saleh I. T. Makki, Reda M. Abdel-Rahman, Hassan M. Faidallah, and Khalid A. Khan Copyright © 2013 Mohammed Saleh I. T. Makki et al. All rights reserved. Mon, 17 Jun 2013 15:25:51 +0000 http://www.hindawi.com/journals/chem/2013/469170/ The adsorption of methylene blue from aqueous solution onto activated carbon prepared from cola nut shell has been investigated under batch mode. The influence of major parameters governing the efficiency of the process such as, solution pH, sorbent dose, initial concentration, and contact time on the removal process was investigated. The time-dependent experimental studies showed that the adsorption quantity of methylene blue increases with initial concentration and decreasing adsorbent dosage. The equilibrium time of 180 min was observed and maximum adsorption was favoured at pH 3.5. The dye removal using 0.1 g of adsorbent was more than 90%. This dosage (0.1 g) was considered as the optimum dosage to remove methylene blue from aqueous solutions. The equilibrium adsorption data were analyzed by the Freundlich, Langmuir adsorption isotherm models. The kinetics of methylene blue solution was discussed by pseudo-first-order, pseudo-second-order, and Elovich models. The adsorption process follows the Elovich rate kinetic model, having a correlation coefficient in the range between 0.9811 and 1. Julius Ndi Nsami and Joseph Ketcha Mbadcam Copyright © 2013 Julius Ndi Nsami and Joseph Ketcha Mbadcam. All rights reserved. Sat, 15 Jun 2013 13:27:49 +0000 http://www.hindawi.com/journals/chem/2013/473584/ The growing concern of climate change and global warming has in turn given rise to a thriving research field dedicated to finding solutions. One particular area which has received considerable attention is the lowering of carbon dioxide emissions from large-scale sources, that is, fossil fuel power. This paper focuses on ionic liquids being used as novel media for CO2 capture. In particular, solubility data and experimental techniques are used at a laboratory scale. Cited CO2 absorption data for imidazolium-, pyrrolidinium-, pyridinium-, quaternary-ammonium-, and tetra-alkyl-phosphonium-based ionic liquids is reviewed, expressed as mole fractions (X) of CO2 to ionic liquid. The following experimental techniques are featured: gravimetric analysis, the pressure drop method, and the view-cell method. Elena Torralba-Calleja, James Skinner, and David Gutiérrez-Tauste Copyright © 2013 Elena Torralba-Calleja et al. All rights reserved. Thu, 13 Jun 2013 17:59:35 +0000 http://www.hindawi.com/journals/chem/2013/820183/ Plants belonging to the Ranunculaceae family, and particularly their seeds, have been a hot research topic in numerous pharmacognosy laboratories. Nigella glandulifera Freyn et Sint (NG) is one of the promising, but relatively insufficiently studied, plants from this family. In this review, we summarize the recently isolated chemical constituents from the seeds of this plant including alkaloids, flavonol glycosides, isobenzofuranone derivatives, saponins, terpenes, terpenoids, and fatty acids. We put also a spotlight on the recently studied therapeutic potentials of such amazing herb seeds as antidiabetes, melanogenesis inhibition, anticancer, anti-inflammatory, antithrombosis, and antiplatelet aggregation effects. Herein, we illustrate certain properties and potentials via selected examples, and thus we suggest more studies to confirm the therapeutic hypotheses, find out new compounds, and eventually to discover novel properties. Besma Boubertakh, Xin-Guang Liu, Xiao-Lan Cheng, and Ping Li Copyright © 2013 Besma Boubertakh et al. All rights reserved. Wed, 12 Jun 2013 10:01:43 +0000 http://www.hindawi.com/journals/chem/2013/703057/ The impact of supercritical CO2 (SC-CO2) process on the quality attributes of fresh-cut coconut has been investigated to establish the acceptability of SC-CO2 treated products by the consumers. Two process conditions, previously identified as optimal to reduce the microbial content of the product, were studied: 12 MPa, 40°C, 30 min and 12 MPa, 45°C, 15 min. The results highlighted that both conditions induced some effects on product attributes. After 30 min of treatment at 12 MPa and 40°C a decrease of lightness (8%), pH (13%), fat content (24%), total phenol content (29%), flavonoid compounds (49%), antioxidant capacity (30%) and an increase of dry matter (11%) and titratable acidity (51.1%) were observed while polyphenol oxidase (PPO) exhibited 35% and 98.5% inactivation. Peroxidase enzyme activity increased by 77.8% and 30.4% at 12 MPa, 40°C, 30 min and 12 MPa, 45°C, 15 min, respectively. Sensory evaluations revealed no significant differences in appearance, texture, taste, and aroma of treated fresh-cut coconut compared to the untreated. The study confirms the feasibility of SC-CO2 process for the pasteurization of fresh fruits with a firm structure and opens the door to the possibility of exploiting such a technology at industrial level. Giovanna Ferrentino, Ana Belscak-Cvitanovic, Drazenka Komes, and Sara Spilimbergo Copyright © 2013 Giovanna Ferrentino et al. All rights reserved. Wed, 12 Jun 2013 09:28:08 +0000 http://www.hindawi.com/journals/chem/2013/509341/ The chloropropyl silica gel was modified with octa(3-aminopropyl)octasilsesquioxane and characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), spectroscopies, and surface and area porosity. The specific sorption capacity of metallic ions (Cu2+ and Ni2+) increases in the following solvent order: water ethanol 42% ethanol ketone. The high values of the constant (K) in the order of 103 L mol−1 suggested the high adsorbent capacity of the modified silica (SGAPC) for Cu2+ and Ni2+. SGAPC was applied to a separation column and shows recoveries of around 100% of copper in samples of sugar cane spirit, vodka, ginger brandy, and ethanol fuel. Devaney Ribeiro Do Carmo, Urquisa De Oliveira Bicalho, Tayla Fernanda a Silveira, Newton Luiz Dias Filho, and Leonardo Lataro Paim Copyright © 2013 Devaney Ribeiro Do Carmo et al. All rights reserved. Sun, 09 Jun 2013 12:07:53 +0000 http://www.hindawi.com/journals/chem/2013/208507/ A. Hamid A. Hadi, Mehmet Emin Duru, and Ana B. Martin-Diana Copyright © 2013 A. Hamid A. Hadi et al. All rights reserved. Sun, 09 Jun 2013 11:30:20 +0000 http://www.hindawi.com/journals/chem/2013/536341/ Pietro Calandra, Valeria La Parola, Vincenzo Turco Liveri, Elefterios Lidorikis, and Fabio Finocchi Copyright © 2013 Pietro Calandra et al. All rights reserved. Tue, 04 Jun 2013 14:29:36 +0000 http://www.hindawi.com/journals/chem/2013/895892/ A novel synthetic approach towards 5-fluoro-2-hydroxy butyrophenone is reported. Using 4-fluorophenol as a raw material, the processes of etherification protection, Friedel-Crafts acylation and demethylation provide the target compound under mild conditions. The structure was characterized by the melting point and IR, MS, 1H-NMR, and 13C-NMR spectroscopy. The bioassay results indicate that the target compound exhibits potent antifungal activities against Valsa mali, Coniella dipodiella, and other agricultural plant fungi. The target compound also shows potent herbicidal activities for Lactuca sativa, a dicotyledon, and Echinochloa crus-galli, a monocotyledon. The toxicity regression C50 values of the compound against Valsa mali, Coniothyrium diplodiella, Lactuca sativa seedling, and Echinochloa crusgalli seedling were calculated by SPSS. The Hormesis effect for roots of Echinochloa crusgalli was confirmed. Fengli Xin, Chunhua Du, Gongjia Lan, and Zhuanping Wu Copyright © 2013 Fengli Xin et al. All rights reserved. Sun, 02 Jun 2013 16:31:21 +0000 http://www.hindawi.com/journals/chem/2013/281341/ A series of eleven butanediamine analogues, of which nine were new, were synthesized by the nucleophilic substitution of aromatic amines and benzylamines with maleic anhydride and tested on four yeast strains of Candida species using the broth microdilution method. Compounds 3a and 3c with an unsubstituted phenyl ring and a 3-methoxyphenyl ring, respectively, are the most active against the fungal species with MIC values ranging from 20.2 to 80.6 μM for C. albicans and C. parapsilosis and 178.5 and 161.2 μM for C. krusei, respectively. Habila J. Dama, Kandappa H. Reddy, Patrick Govender, and Neil A. Koorbanally Copyright © 2013 Habila J. Dama et al. All rights reserved. Sun, 02 Jun 2013 14:21:59 +0000 http://www.hindawi.com/journals/chem/2013/837649/ The reduction behaviour of magnetite using graphite under ball-milling conditions (using a planetary mono mill, Fritsch Pulverisette 6) has been investigated. The reaction of magnetite and graphite at different milling conditions leads to the formation of Fe2+ and Fe3+ species, the former increasing at the expense of Fe3O4. Fe3O4 completely disappeared after a ball to powder ratio of 50 : 1 and beyond. The Fe2+ species were confirmed to be due to FeO using Mössbauer Spectroscopy and X-ray diffraction techniques. Scanning electron microscopy and transmission electron microscopy analyses confirm the reduction of magnetite to wüstite. Ledwaba Harry Moloto, Sunnyboy Stanley Manzini, and Ezekiel Dixon Dikio Copyright © 2013 Ledwaba Harry Moloto et al. All rights reserved. Thu, 30 May 2013 18:58:13 +0000 http://www.hindawi.com/journals/chem/2013/801069/ Supercritical assisted atomization (SAA) is an efficient technique to produce microparticles and composite microspheres formed by polymers and pharmaceutical compounds. In this work polyvinylpyrrolidone (PVP) was proposed as carrier for pharmaceutical compounds that show a poor solubility in water medium. Indeed, this polymer is hydrosoluble and can be generally used to enhance the dissolution rate of hydrophobic compounds when finely dispersed in it. However, it is difficult to obtain coprecipitates with a uniform dispersion of the active molecule using other micronization techniques. The experiments were performed using ethanol as solvent; SAA plant was operated at 40°C and 76 bar in the saturator and 70°C and 1.6 bar in the precipitator. Three different dexamethasone/polymer weight ratios were selected: 1/2, 1/4, and 1/8. Produced composite particles showed a regular, spherical shape and a mean diameter ranging from about 0.8 to 1 μm, depending on the polymer/drug weight ratio. Dissolution analysis demonstrated that microparticles containing a lower drug amount show a higher dissolution rate. Sara Liparoti, Renata Adami, Giuseppe Caputo, and Ernesto Reverchon Copyright © 2013 Sara Liparoti et al. All rights reserved. Thu, 30 May 2013 12:39:39 +0000 http://www.hindawi.com/journals/chem/2013/951392/ This paper presents our attempt to investigate scopes and the limitations of olefin cross-metathesis (CM) reaction in the synthesis of complex C-glycosides of genistein and evaluation of their antiproliferative activities. Novel genistein glycoconjugates were synthesized with the utility of CM reaction initiated by first and second generation of Grubbs catalysts. The relative reactivity of utilized olefins, based on categories proposed by Grubbs, was estimated. In vitro experiments in cancer cell lines showed that the selected derivatives (3a and 3f) exhibited higher antiproliferative potential than the parent compound, genistein, and were able to block the cell cycle in the G2/M phase. The observed mechanism of action of C-glycosidic derivatives was similar to the activity of their O-glycosidic counterparts. These compounds were stable in culture medium. The obtained results show that our approach to genistein modification with application of cross-metathesis reaction allowed to obtain stable glycoconjugates with improved anticancer potential, compared to the parent isoflavone. Aleksandra Rusin, Maciej Chrubasik, Katarzyna Papaj, Grzegorz Grynkiewicz, and Wiesław Szeja Copyright © 2013 Aleksandra Rusin et al. All rights reserved. Wed, 29 May 2013 16:49:27 +0000 http://www.hindawi.com/journals/chem/2013/187572/ Liquid-liquid extraction of various alkalis (Li+, Na+, K+, and Cs+), transition metals (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Hg2+), and Pb2+ cations with phenylglyoxime (L1), p-tolylglyoxime (L2), N′-(4′-Benzo[15-crown-5])phenylaminoglyoxime (L3), and N′-(4′-Benzo[15-crown-5])-p-tolylaminoglyoxime (L4) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding two glyoximes and their macrocyclic glyoxime ether derivatives were also examined. Crown ether groups having ligands (L3, L4) carry especially Na+ cation from aqueous phase to organic phase. The extraction equilibrium constants () for complexes of ligands with Cu2+ and Hg2+ metal picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants () were determined to be 12.27, 13.37, 12.94, and 12.39 for Cu2+ and 10.29, 10.62, 11.53, and 11.97 for Hg2+ with L1–L4, respectively. Nazan Karapinar, Emin Karapinar, and Emine Ozcan Copyright © 2013 Nazan Karapinar et al. All rights reserved. Wed, 29 May 2013 11:03:11 +0000 http://www.hindawi.com/journals/chem/2013/640913/ The degradation rate of tissue engineering scaffolds should match the regeneration rate of new tissues. Controlling the degradation behavior of silk fibroin is an important subject for silk-based tissue engineering scaffolds. In this study, Antheraea pernyi silk fibroin was successfully modified with succinic anhydride and then characterized by zeta potential, ninhydrin method, and FTIR. In vitro, three-dimensional scaffolds prepared with modified silk fibroin were incubated in collagenase IA solution for 18 days to evaluate the impact of acylation on the degradation behavior. The results demonstrated that the degradation rate of modified silk fibroin scaffolds was more rapid than unmodified ones. The content of the -sheet structure in silk fibroin obviously decreased after acylation, resulting in a high degradation rate. Above all, the degradation behavior of silk fibroin scaffolds could be regulated by acylation to match the requirements of various tissues regeneration. Xiufang Li, Ceng Zhang, Lingshuang Wang, Caili Ma, Weichao Yang, and Mingzhong Li Copyright © 2013 Xiufang Li et al. All rights reserved. Tue, 28 May 2013 09:04:27 +0000 http://www.hindawi.com/journals/chem/2013/402172/ Antonia Pérez de los Ríos, Angel Irabien, Frank Hollmann, and Francisco José Hernández Fernández Copyright © 2013 Antonia Pérez de los Ríos et al. All rights reserved. Mon, 27 May 2013 16:39:08 +0000 http://www.hindawi.com/journals/chem/2013/864926/ Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2 nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume). In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate), PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight). The supercritical CO2 foaming was performed at four different temperatures (40, 65, 75, and 85°C) and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from to  μm, whereas, the cell density was increased from to cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology. Deniz Rende, Linda S. Schadler, and Rahmi Ozisik Copyright © 2013 Deniz Rende et al. All rights reserved. Sun, 26 May 2013 10:46:09 +0000 http://www.hindawi.com/journals/chem/2013/980243/ A new calcium coordination polymer [Ca(HL-MA)]n (H3L-MA = L-malic acid) has been solvothermally synthesized. The structure of the newly synthesized complex has been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, reflectance UV-Vis & IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). The single crystal structure analysis showed that the complex forms three-dimensional framework. The new Ca(II) complex has displayed very high thermal stability which was inferred from TGA and PXRD results. As far as the optical property of the new complex is concerned, the complex emitted its own characteristic sensitized luminescence. Duraisamy Senthil Raja, Jheng-Hong Luo, Ting-Guang Chang, Sheng-Han Lo, Cheng-You Wu, and Chia-Her Lin Copyright © 2013 Duraisamy Senthil Raja et al. All rights reserved. Thu, 23 May 2013 15:33:30 +0000 http://www.hindawi.com/journals/chem/2013/206847/ Metal-Schiff base complexes have attracted continued research interest regarding their intriguing and useful features, while the electronic properties of these complexes in the confined space have not been sufficiently addressed in previous studies. In this work, a new zinc(II)-Schiff base complex bis(N-dodecyl salicylideneiminato)Zn(II) (1) was synthesized and subsequently loaded in an inorganic solid host. A large red shift (~40 nm) of the absorption onset was recorded, when the microenvironment of 1 changed from the solvent ethanol to the inorganic solid medium, evidencing the confined space effect. The marked shift of the absorption onset was associated with a band-gap reduction between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Theoretical calculation results showed that the confined space effect is distance dependent and exerts a more profound influence on the HOMO than the LUMO within an effective distance range. An initial study implied that the confined space effect is also accompanied with the electron density variation. Peng Shang and Lei Zhang Copyright © 2013 Peng Shang and Lei Zhang. All rights reserved. Thu, 23 May 2013 15:33:06 +0000 http://www.hindawi.com/journals/chem/2013/469470/ An improvement to our solid phase strategy to generate pharmacologically interesting molecule libraries is proposed here. The synthesis of new o-chlorophenol-functionalised solid supports with very high loading (0.18–0.22 meq/g for control pore glass (CPG) and 0.25–0.50 meq/g for TG) is reported. To test the efficiency of these supports, we prepared nucleotide and oligonucleotide models, and their coupling yields and the purity of the crude detached materials were comparable to previously available results. These supports allow the facile and high-yield preparation of highly pure phosphodiester and phosphoramidate monoester nucleosides, conjugated oligonucleotides, and other yet unexplored classes of phosphodiester and phosphoramidate molecules. Valeria Romanucci, Armando Zarrelli, Lorenzo De Napoli, Cinzia Di Marino, and Giovanni Di Fabio Copyright © 2013 Valeria Romanucci et al. All rights reserved. Thu, 23 May 2013 13:35:44 +0000 http://www.hindawi.com/journals/chem/2013/465825/ A simple and sensitive solid-phase extraction (SPE) procedure combined with flame atomic absorption spectrometry (FAAS) was designed for the extraction and determination of trace amounts of silver. A column of immobilized 2-mercaptobenzothiazole (MBT) on microcrystalline naphthalene was used as the sorbent. Silver was quantitatively retained on the column in the pH range of 0.5–6.0. After extraction, the solid mass consisting of silver complex and naphthalene was dissolved out of the column with 5.0 mL of dimethylformamide, and the analyte was determined by flame atomic absorption spectrometry (FAAS). Under the optimum experimental conditions, the adsorption capacity was found to be 1.18 mg of silver per gram of the sorbent. A sample volume of 800 mL resulted in a preconcentration factor of 160. The relative standard deviation obtained for ten replicate determinations at a concentration of 0.8 µg L−1 was 1.4%, and the limit of detection was 0.02 µg L−1. The method was successfully applied to the determination of silver in radiology film, waste water, and natural water samples. The accuracy was examined by recovery experiments, independent analysis by electrothermal atomic absorption spectrometry, and analysis of two certified reference materials. Farid Shakerian, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, and Mahdieh Shabani Copyright © 2013 Farid Shakerian et al. All rights reserved. Tue, 21 May 2013 10:02:23 +0000 http://www.hindawi.com/journals/chem/2013/540240/ A novel molecularly imprinted polymer (MIP) powder designed for the selective removal of interfering chlorophyll pigment from heavily pigmented green plant extracts during pesticide residue analysis or analysis for bioactives in natural product research is reported. The polymer powder imprinted with chlorophyll was synthesized by copolymerizing the functional and cross-linking monomers, methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA), respectively. During batch rebinding experiments, the MIP effectively removed chlorophyll from neat chlorophyll standards, green medicinal plants, and spinach extracts with determined absorbance as high as 2.501 absorbance units (Au) to as low as 0.084 Au after the optimum quantity of the MIP (170 mg mL−1) was added as the adsorbent prior to instrumental analysis. The determined 0.084 Au absorbance was far below the absorbance of 2% chlorophyll (0.401 Au) regarded as the cut-off point for interfering chlorophyll. Thus the newly developed polymer presents itself as a suitable adsorbent for the selective removal of chlorophyll from heavily pigmented, chlorophyll containing extracts. Bareki Shima Batlokwa, Janes Mokgadi, Ronald Majors, Charlotta Turner, and Nelson Torto Copyright © 2013 Bareki Shima Batlokwa et al. All rights reserved. Mon, 20 May 2013 16:17:51 +0000 http://www.hindawi.com/journals/chem/2013/947137/ Traditional approaches to the development of integrated circuits involve the use and/or manufacture of toxic materials that have a potential environmental impact. An extensive research has been done to design environmentally benign synthetic polymers containing nucleic acid bases, which can be used to enhance the photoresistor technologies. Water soluble, environmentally benign photopolymers of 1-(4-vinylbenzyl) thymine (VBT) and vinylphenyl sufonate (VPS) undergo a photodimerization reaction when exposed to low levels of ultraviolet irradiation leading to an immobilization of the copolymer on a variety of substrates. Plackett-Burman design (PBD) and central composite design (CCD) were applied to identify the significant factors influencing the polymer crosslinking and dye adsorption processes, which are relevant in the fabrication of copolymer films for potential photoresist use. The PBD results assigned a maximum absorption signal of 0.67, while optimal conditions obtained in this experiment following the CCD method predictions provided a response of 0.83 ± 0.03, being a solid foundation for further use of this methodology in the production of potential photoresistors. The pH effect was relevant for low concentrations but not significant for higher concentrations. To the best of our knowledge, this was the first report applying statistical experimental designs to optimize the crosslinking of thymine-based polymers. Julieta Ledesma, Santiago A. Bortolato, Carlos E. Boschetti, and Débora M. Martino Copyright © 2013 Julieta Ledesma et al. All rights reserved. Mon, 20 May 2013 11:37:56 +0000 http://www.hindawi.com/journals/chem/2013/861021/ 1,3-Dialkylimidazolium-based ionic liquids were chemically synthesized and bonded on the surface of magnetic nanoparticles (MNPs) with easy one-step reaction. The obtained six kinds of ionic liquid modified MNPs were characterized with transmission electron microscopy, thermogravimetric analysis, magnetization, and FTIR, which owned the high adsorption capacity due to the nanometer size and high-density modification with ionic liquids. Functionality of MNPs with ionic liquids greatly influenced the solubility of the MNPs with organic solvents depending on the alkyl chain length and the anions of the ionic liquids. Moreover, the obtained MNPs showed the specific extraction efficiency to organic pollutant, polycyclic aromatic hydrocarbons, while superparamagnetic property of the MNPs facilitated the convenient separation of MNPs from the bulks water samples. Ying Li, Ning Tang, Fuyuhiko Inagaki, Chisato Mukai, and Kazuichi Hayakawa Copyright © 2013 Ying Li et al. All rights reserved. Sun, 12 May 2013 18:15:10 +0000 http://www.hindawi.com/journals/chem/2013/136908/ In this high-technology application, age functional dyes especially polymethine dyes have captured much attention of the researchers due to their immense potential for high-tech uses. Polymethine dyes show promising absorption spectra in the visible range, which can be easily exploited for the use of written text copying, photographic imaging, or photothermographic recording materials. Keeping this in mind, our research is composed of an investigation of two triphenylamino-based polymethine dyes, a known polymethine dye 3 and a new one polymethine dye 5, which have been synthesized by the reaction of 4-(diphenylamino) benzaldehyde 2 and 4,-(phenylazanediyl) dibenzaldehyde 4 with 4,-vinylidene-bis(N, N-dimethylaniline) 1. Based on bis-dimethylaminophenylethylene moiety, the new polymethine dye showed more high absorption spectra in the range of 600–700 nm than that of the known polymethine dye based on bis-dimethylaminophenylethylene moiety. Their maximum spectra were exhibited at 637 nm and 653 nm, respectively. Their leuco-converted reversible colored forms were also investigated. Saleem Ullah, Irshad Ahmad, Yatimah Alias, Ismail Yusoff, and Muhammad Aqeel Ashraf Copyright © 2013 Saleem Ullah et al. All rights reserved. Wed, 08 May 2013 14:48:46 +0000 http://www.hindawi.com/journals/chem/2013/165970/ A novel experimental method has been established for the first time to evaluate the distribution behavior of water soluble hydrophobically associated polymer AP-P4 in the oil-water-solid three-phase systems, based on the static adsorption principle. Suitable analysis method has been selected to measure the concentration of polymer in every phase. The enrichment of polymer has been observed between the oil-aqueous interlayer. The distribution coefficient of AP-P4 is obtained along with the variation of concentration and total salinity. The experimental method is helpful to reveal the property of polymer solution and has potential usage in predicting the adsorption and retention in polymer flooding and the wastewater dealing of polymer flooding. Ruyin Li, Guorong Tan, and Jian Zhang Copyright © 2013 Ruyin Li et al. All rights reserved. Tue, 07 May 2013 13:11:18 +0000 http://www.hindawi.com/journals/chem/2013/590512/ Purple sweet potato colour (PSPC) was a kind of natural pigment that attracted the general concern in recent years. In this paper, the response surface methodology was employed to optimize the extraction conditions of PSPC. The results showed that the extraction yield of purple colour was 11.6355 mg/g at the optimum extraction conditions of extraction temperature 60°C, extraction time 1 h, the ratio of solid to liquid ratio of 1 : 30, and acidified ethanol solution concentration 80%. Stability experiment showed that Fe3+ and Al3+ could increase the stability of PSPC, but Cu2+, Zn2+, and Pb2+ would decrease the stability of PSPC. Ascorbic acidified could significantly increase the stability of PSPC, and Na2SO3 would reduce the PSPC’s stability. Jinwei Li, Lianfu Zhang, and Yuanfa Liu Copyright © 2013 Jinwei Li et al. All rights reserved. Tue, 07 May 2013 11:44:37 +0000 http://www.hindawi.com/journals/chem/2013/850297/ The M06 family of density functionals has been assessed for the calculation of the molecular structure and properties of the Naringin molecule. The chemical reactivity descriptors have been calculated through Conceptual DFT. The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices and the dual descriptor . A comparison between the descriptors calculated through vertical energy values and those arising from the Koopmans' theorem approximation has been performed in order to check for the validity of the last procedure. Jorge Ignacio Martínez-Araya, Guillermo Salgado-Morán, and Daniel Glossman-Mitnik Copyright © 2013 Jorge Ignacio Martínez-Araya et al. All rights reserved.