Dependence of hydrogen released on the charge state of incident ions

The behavior of polymers under heavy ion bombardment is of great interest. In the present study, hydrogen released from polypropylene (PP) and polyethylene terephthalate (PET) was investigated as a function of charge state (11⁺, 14⁺, and 25⁺) for 130 MeV ¹⁰⁷Ag ions. It was found that hydrogen released from the polymers varies as α q ⁿ , where n was found to be 2.98 and 1.94 for PP and PET, respectively, when compared with the value of ～3.0 reported in the literature for different polymers and ion combinations. Radii of the damaged zones or ion track formed were deduced from the slope of the hydrogen released versus ion fluence curves. This radius was also found to depend upon the charge state of the incident ion. It varies as β q ^m , where m is 1.25 and 0.741 for PP and PET, respectively.     

Cu-catalyzed dehydrogenative C?O arylation for the synthesis of 6-methyl benzofuro[3,2-c] quinoline derivatives

A novel strategy for the synthesis of 6-methyl benzofuro[3,2-c] quinoline derivatives via copper-catalyzed dehydrogenative C O arylation has been presented. Optimization studies have been carried out by varying various catalysts, bases, solvents, and other physical parameters. Keeping use of this dehydrogenative cross-coupling C O arylation reaction, a variety of bioactive building blocks like fused benzofuro quinoline heterocycles were smoothly assembled in moderate to higher yields.     

Synthesis,spectroscopic characterization and in vitro studies of antimicrobial activity of bis(diorganodithiocarbamato)organodithiocarbonatobismuth (III) complexes

A brief account of the synthesis, spectroscopic characterization and the antimicrobial (bacterial and fungal) behaviour of bis(diorganodithiocarbamato)organodithiocarbonatobismuth(III) complexes is presented. The reaction of bis(diorganodithiocarbamato)bismuth(III) chloride with potassium organodithiocarbonate in equimolar ratio yielded the corresponding mixed derivatives of the type [R′₂NCS₂]₂BiS₂COR [where, R′ = CH₃ and C₂H₅; R = Et, Prⁿ, Prⁱ, Buⁿ and Buⁱ]. These have been characterized by molecular weight determinations, melting points (only solid complexes) and elemental (C, H, N, S and Bi) analysis as well as spectral IR and NMR [¹H and ¹³C] studies. The antibacterial and antifungal activities of the free ligands and their bismuth complexes were found in vitro by the disc diffusion method. The complexes showed good antibacterial and antifungal effect on some selected bacterial and fungal strains. The antimicrobial activities of two standard antibiotics (Chloroamphenicol and Terbinafin) were also measured and compared with these complexes. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis and characterization of triarylphosphine complexes of zinc(II) halides

Both 1:1 and 1:2 complexes are formed by zinc(II) halides and triarylphosphines unless electronic and/or steric factors intervene. Tri‐p‐chlorophosphine (a weaker base than PPh₃) forms only a 1:1 complex, whereas bulky tri‐(ortho‐substituted phenyl)phosphines do not react. The complexes ZnX₂PR₃ and ZnX₂(PR₃)₂ have been characterized by elemental analyses, conductance, far‐IR and (in a few cases) Raman spectral studies. The Zn–X and Zn–P stretching and Zn–X bending vibrational frequencies have been assigned in the complexes with a pseudo‐tetrahedral structure of C_2v symmetry. Copyright © 2003 John Wiley & Sons, Ltd.     

Glycated hemoglobin biosensing integration formed on Au nanoparticle-dotted tubular TiO2 nanoarray

Excessive glucose present in the blood of diabetic patients binds with the hemoglobin of red blood cells resulting in the formation of glycated hemoglobin (HbA_1c). Measurement of HbA_1c levels may help in identifying the efficacy of the ongoing treatment and hence provide a better control over the disease. In the present study, we have synthesized a sensitive and stable scaffold, which consists of Au nanoparticles (GNPs)-dotted tubular TiO₂, for the construction of an electrochemical HbA_1c biosensor. 12-phosphotungstic acid has been used as a reducer after depositing well-dispersed GNPs on TiO₂ nanotubes (TiO₂ NTs) and an electron mediator by accelerating the electron transfer between the conductor and protein. The fabricated electrode was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopic analysis (EIS). Biosensor exhibited low detection limit (0.5 μM), fast response time (3 s) and wide linearity (from 0.5 to 2000 μM). The working electrode was used 100 times over 4 months, when stored at 4 °C. The HbA1c biosensor was then effectively used to measure the % of HbA_1c in the blood of apparently healthy persons and diabetic patients.     

Electrical,structural and thermal studies of carbon nanotubes from natural legume seeds: kala chana

ABSTRACT

Carbon nanotubes (CNTs) are the carbon materials measured at nanoscale level and they are defined in two types according to the number of concentric layers, i.e. single-layer tube is single-walled nanotubes, while multi-layer tube structure is called multi-walled nanotubes. The green method synthesis for the preparation of CNTs begins with the smashing of legume seeds kala chana, and then they form complex with cobalt salt. Desiccation of the complex compound forms cobalt salt and seed protein. The complex is then decomposed at 625 ºC in muffle furnace for 20 min. Purification of the decomposed sample is done through acid wash treatment and dried in vacuum oven. The confirmations of CNTs are done by nuclear magnetic resonance and Fourier transform infrared, which analyzes the denatured protein, reacted to the metal salt. X-Ray diffraction determines the MWNTs with transmission electron microscope (TEM) reports the network structure of CNTs. thermal gravimetric analysis (TGA)–differential thermal analysis (DTA)–thermogravimetric analysis (DTG) tests the amount of sample under thermal treatment. Vibrating sample magnetometer determines the paramagnetic nature of CNTs. CNTs thus prepared can be used in mechanical fields, in solar cells, in electronics fields, etc. because of their multidisciplinary properties. The synthesized CNTs are eco-friendly in nature, prepared by the legume seed natural precursor.     

Acylmethyl(aryl)tellurium(IV,II) derivatives: intramolecular secondary bonding and steric rigidity

Electrophilic substitution of acylmethanes (methyl ketones), RCOCH3 (R = i-Pr, 1; Et, 2; Me, 3) with aryltellurium trichlorides, ArTeCl3 (Ar = 1-C10H7, Np, A; 2,4,6-Me3C6H2, Mes, B; 4-MeOC6H4, Anisyl, C) under mild conditions affords the corresponding acylmethyl(aryl)tellurium dichlorides (RCOCH2)ArTeCl2. Reduction of the dichlorides, gives tellurides, (i-PrCOCH2)ArTe, 1A-1C, which give the corresponding dihalides, (i-PrCOCH2)ArTeX2 (X = Cl, 1Aa-1Ca; Br, 1Ab-1Cb; I, 1Ac-1Cc) when reacted in situ with SO2Cl2, Br2 or I2. The unsymmetric tellurides are labile towards disproportionation and attempts to obtain them lead to the isolation of Ar2Te2 except in the case of (i-PrCOCH2)MesTe (1B), which represents an interesting example of a kinetically stable aryl(alkyl)telluride. All the dihalomesityltellurium(IV) derivatives show separate 1H and 13C NMR signals for the ortho methyls irrespective of the sizes of R and X ligands. The telluride, 1B with free rotation about Te-C(mesityl) bond shows, like the unsymmetric diorganotellurium(IV) dihalides, only one 125Te NMR signal. The 1,4-chelating behavior of the acyl ligand among diorganotellurium(IV) compounds is inferred from the X-ray diffraction data for 1Aa, 1Ac, 1Ba, 1Bb, 1cA and 1Cc which are indicative of the presence of intramolecular Te...O secondary bonding interactions (SBIs) at least in the solid state. As a consequence, steric repulsion in case of the mesityltellurium(IV) derivatives, 1Ba and 1Bb, reaches the threshold so as to cause loss of two-fold rotational symmetry of the mesityl group about the Te-C(mesityl) bond axis. Intermolecular C-HO...O H-bonding interactions appears to stabilize such an orientation of the aryl ligand at least in the solid state.     

Application of Vitamin E TPGS in ocular therapeutics – Attributes beyond excipient

Diseases affecting the anterior segment and the external surface of the eye are usually treated by drugs applied topically. The formulations designed for this purpose are developed to deliver active pharmaceutical agents to the eye optimally. These formulations are prepared by adding various agents (excipients) that help to maintain stability of the formulation, prevent microbial contamination, and allow easy administration with adequate drug bioavailability with the minimum ocular irritation and toxic effects at the administration site. The excipients do not have their own pharmacological actions, but Vitamin E TPGS (d-α-Tocopheryl polyethylene glycol 1000 succinate) seems to break this notion. Besides having drug formulation enhancement properties, it also possesses antioxidant properties, which have been found to have a beneficial effect on various ophthalmological diseases such as age-related macular degeneration, uveitis, glaucoma, and cataract. In this review, we primarily focus on the properties and applications of Vitamin E TPGS in ocular drug delivery and the benefits of Vitamin E (Vit E) in numerous sight-threatening ailments of the rear and front segment of the eye. Additionally, p-glycoprotein inhibition and the anti-cancer potential of vitamin E TPGS have also been summarized.     

Mixed bis(morpholine‐4‐dithiocarbamato‐S,S′)antimony(III) complexes: synthesis,characterization and biological studies

Some mixed bis(morpholine‐4‐dithiocarbamato‐S,S′)antimony(III) complexes [(OC₄H₈NCS₂)₂SbL] with oxygen or sulfur donor ligands [L = ―OOCCH₃ ( 1 ), ―OOCC₆H₅ ( 2 ), ―SOCCH₃ ( 3 ), ―SCH₂COOH ( 4 ), ―OOCC₆H₄(OH) ( 5 ), ―SCH₂CH₂CH₃ ( 6 ), ―OC₆H₅ ( 7 ), ½ ―SCH₂CH₂S― ( 8 )] have been synthesized by reacting the chloro‐bis(morpholine‐4‐dithiocarbamato‐S,S′)antimony(III) with corresponding oxygen or sulfur donor ligands in 1:1 or 2:1 stoichiometries. These have been characterized by melting point, molecular weight determination (cryoscopically), antimony (iodometrically) and sulfur (gravimetrically) estimation, elemental analyses (C, H and N), UV–visible, FT‐IR, far IR, multinuclear NMR (¹H and ¹³C)], TG/DTA analysis, ESI–mass and powder X‐ray diffraction studies. The splitting of the strong band observed at 1046–1066 cm^?1 due to υ(C―S) indicated anisobidentate mode of binding of the dithiocarbamate group, which was further supported by a ¹³C NMR signal appearing at around δ 200 due to NCS₂ moiety. The base peak observed at m/z 444.9 supports the strong chelating nature of the morpholine‐4‐dithiocarbamate compared to the other hetero ligands used. TGA revealed that, complexes 21 and 4 were decomposed in three steps; also 6 was decomposed in two steps, followed by the formation of Sb₂S₃. The results obtained by antimicrobial screening tests indicate that complex 3 showed a maximum zone of inhibition (20 mm) against Trichoderma ressie at a concentration of 200 µg ml^?1. Complexes 2 , 3 and 8 are most active (zone of inhibition (ZI) 17–20 mm) against both of the fungal species Aspergillus niger and Trichoderma ressie as well as complex 4 (ZI 17 mm) and 6 (ZI 18 mm) against Trichoderma ressie. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and self aggregation properties of ester-functionalized heterocyclic pyrrolidinium surfactants

Linear fatty alcohols on reaction with chloro/bromo acetic acid in the presence of catalytic amount of p-toluene sulphonic acid monohydrate under solvent-free conditions are converted into alkyl-2-haloacetate which on reaction with N-methyl pyrrolidine gives ester-functionalized pyrrolidinium surfactants. Thus, new series of ester-functionalized heterocyclic pyrrolidinium head group containing cationic surfactants have been synthesized by green approach via energy saving and cost effective methodology. These new surfactants have been investigated for their surface properties by surface tension, conductivity, and fluorescence method. Surface properties of these surfactants have been found to be far better compared to conventional heterocyclic cationic surfactants having similar hydrophobic alkyl chain length.