Organothiol Monolayer Formation Directly on Muscovite Mica

Organothiol monolayers on metal substrates (Au, Ag, Cu) and their use in a wide variety of applications have been extensively studied. Here, the growth of layers of organothiols directly onto muscovite mica is demonstrated using a simple procedure. Atomic force microscopy, surface X‐ray diffraction, and vibrational sum‐frequency generation IR spectroscopy studies revealed that organothiols with various functional endgroups could be self‐assembled into (water) stable and adaptable ultra‐flat organothiol monolayers over homogenous areas as large as 1 cm². The strength of the mica–organothiol interactions could be tuned by exchanging the potassium surface ions for copper ions. Several of these organothiol monolayers were subsequently used as a template for calcite growth.     

Simultaneous Determination of Marmin,Skimmianine, Umbelliferone,Psoralene, and Imperatorin in the Root Bark of Aegle Marmelos by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - Aegle marmelos (Rutaceae) has gained traditional therapeutic importance owing to their coumarins (umbelliferone, psoralene, marmin,...     

An enantiodivergent and formal synthesis of paroxetine enantiomers by asymmetric desymmetrization of 3-(4-fluorophenyl)glutaric anhydride with a chiral SuperQuat oxazolidin-2-one

The asymmetric desymmetrization of 3-(4-fluorophenyl)glutaric anhydride 9 with lithiated chiral oxazolidin-2-one 8 has been studied. The desymmetrized product was formed with >90% de and converted into known intermediates for both (+)- and (?)-paroxetines.     

Investigation of linear and nonlinear frequency modulated excitation effects on tissue harmonic imaging

The generation of tissue harmonics is due to nonlinear nature of ultrasound wave propagation in biological tissues.The tissue harmonics for imaging i.e.tissue harmonic imaging (THI)uses higher frequency components for imaging in which the resolution improves significantly but signal-to-noise ratio(SNR)and penetration depth remains low as compared to both fundamental and second harmonic imaging.The coded excitations have potential to improve the SNR which ultimately leads to improved penetration depth.In the present work,the linear frequency modulated(chirp/LFM)and nonlinear frequency modulated(NLFM)signals have been used to investigate the nonlinear ultrasound wave propagation and harmonic generation in biological tissues.The SNR has been found to be substantially improved for coded tissue harmonic imaging(CTHI)as well as for coded superharmonic imaging(CSHI).     

Excess thermo dynamical parameters of binary mixtures of toluene and mesitylene with anisaldehyde using ultrasonic technique at different temperatures

The densities, viscosities, and ultrasonic velocities of the binary mixture of toluene and mesitylene with anisaldehyde have been measured at 303.15, 308.15, 313.15, and 318.15 K for the entire range of mole fraction of anisaldehyde. From the data the excess adiabatic compressibility (β ^E), excess free volume (V _f^E), excess internal pressure (π ^E), excess enthalpy (H ^E), and excess Gibb’s free energy of activation of flow (G* ^E) for the binary mixture over the additive values were calculated. In light of these parameters molecular interactions involved between the component liquids have been discussed.     

Synthesis of Sulfonated Cholesterol Derivatives—Electrical,Thermal, and Optical Properties

Poly(cholesterylacrylatesulfone) (PCHAS) and poly(cholesterylacrylatesulfone-co-1-hexene)s (PCHASHs) at different ratios are synthesized from the monomer cholesteryl acrylate. The liquid crystalline phases are observed under a hot stage fitted with a polarizing optical microscope. The polysulfone and copolysulfones are characterized by FT-IR, ¹H-NMR, DSC, and TGA techniques. From SEM (EDX) the qualitative amounts of elemental sulfur found in PCHAS and PCHASH11 are 2.90 weights (%) and 4.39 weights (%), respectively. The GPC data using THF as the solvent shows that the number average molecular weight of the PCHAS is 5268 g/mol and the molecular weights of the PCHASHs are higher than the PCHAS.     

Photodegradation of Methanol Under UV–Visible Irradiation by Titania Dispersed on Polyester Cloth

Titania supported on polyester fabric (TiO₂–PY) with varying titania loadings (2–7 wt%) were prepared via the dip-coating method at room temperature using an aqueous slurry of anatase titania. Structural and morphological characterizations by X-ray diffraction and scanning electron microscopy revealed that the titanium dioxide crystallites deposited on the surface of the polyester fabric were in the micrometer range while their phase remained to be anatase. Photocatalytic activity of TiO₂–PY fabric catalysts was evaluated for vapor-phase oxidation of methanol in air as a test reaction in the presence of UV as well as solar radiation under ambient conditions. These catalysts were found to be quite active in both UV and solar irradiation with activity being higher in the former case. CO₂ yield from photo-oxidation of methanol depended on titania content and also on its dispersion over polyester fabric support.     

Synthesis and characterization of glycol-modified vanadium(V) oxoisopropoxide and their oximato derivatives: sol–gel transformations of [VO(OPr i )3], [VO{OCH2CH2OCH2CH2O}{OPr i }] and [VO{OCH2CH2OCH2CH2O}{ON=C(CH3)(C4H3S-2)}] to vanadia

Reaction of [VO(OPr ⁱ )₃] (1) with [O(CH₂CH₂OH)₂] in 1:1 molar ratio in anhydrous benzene yield glycol-modified precursor, [VO{OCH₂CH₂OCH₂CH₂O}{OPr ⁱ }] (2). Further reactions of (2) with internally functionalized oximes in anhydrous benzene yield heteroleptic complexes of the type [VO{OCH₂CH₂OCH₂CH₂O}{ON=C(R)(Ar)}] (3–8) {where R=CH₃, Ar=C₄H₃O-2 (3), C₄H₃S-2 (4), C₅H₄N-2 (5); and when R=H, Ar=C₄H₃O-2 (6), C₄H₃S-2 (7), C₅H₄N-2 (8)}. All these derivatives have been characterized by elemental analyses, molecular weight measurements and spectroscopic techniques. The crysoscopic molecular weight measurement as well as FAB mass study suggests dimeric nature of (2). However, FAB mass spectrum of (4), and the crysoscopic molecular weight measurements of (3), (4), (5) and (6) indicate the monomeric behavior of the oximato derivatives (3–8). Hexa-coordination around vanadium(V) has been proposed for both monomeric and dimeric derivatives. Sol–gel transformations of (1), (2) or (4) to vanadia [(a), (b) or (c), respectively] have been carried out at low sintering temperature (600 °C). The XRD patterns of (a), (b) or (c) indicate formation of a single orthorhombic phase in all the three cases. The SEM images suggest grain like [for (a) and (b)] and rod like [for (c)] morphology of the crystallites. IR, Raman spectra as well as EDX analyses indicate formation of pure vanadia. Absorption spectra of the vanadia (b) and (c) suggest energy band gaps of 2.53 and 2.65 eV, respectively.     

A catalyst free convenient one-pot synthesis of multisubstituted chromeno-thiazolones

Herein, we report a simple, convenient and catalyst free one-pot synthesis of chromenothiazolone analogues via multicomponent reaction between thiazolidine-2,4-dione, aromatic aldehyde and phenol. This reaction proceeded smoothly in good to excellent yields and offered several other advantages including short reaction time, simple experimental workup procedure and no byproduct.