Synthesis and mesomorphic characterization of azoesters with a coumarin ring

We have synthesized a homologous series of azoesters consisting of a coumaryl moiety as the end group. Eleven derivatives of this series exhibit mesomorphism. The nematic mesophase is exhibited from ethyl homologue onward, while the smectic phase commences at the pentyl derivative and is exhibited along with the nematic phase up to the hexadecyl derivative. The N-I transition temperatures curves show the usual odd-even effect. All the compounds in this series are thermally stable and exhibit a wide mesomorphic range of nearly 120°C. Their thermal stabilities and other characteristics are discussed.     

A radioimmunoassay for serum estradiol

A radioimmunoassay procedure to measure estradiol levels in human serum was developed using¹²⁵I labeled estradiol and antiestradiol antibody raised in-house using the estradiol-6-CMO-BSA as the immunogen. Controlled process serum was used to maintain the serum matrix and sample-standard identity. The assay was validated by analysing several (n=40) samples and comparing with established commercial assays. The assay had a sensitivity of 35 pg/mL and a range of 50 pg/mL to 5 ng/mL. The interassay C.V. were between 2 to 10% while the intraassay C.V. were between 2 and 8%. This assay is sensitive enough for monitoring ovulation and hypersecretions in ovarian tumours and was primarily developed to be used as an in-house assay in the local hospitals.     

Practicality of Tetragonal Nano-Zirconia as a Prospective Sorbent in the Preparation of 99Mo/99mTc Generator for Biomedical Applications

The feasibility of using tetragonal nano-zirconia (t-ZrO₂) as an effective sorbent for developing a ⁹⁹Mo/^99mTc chromatographic generator was demonstrated. The structural characteristics of the sorbent matrix were investigated by different analytical techniques such as XRD, BET surface area analysis, FT-IR, TEM etc. The material synthesized was nanocrystalline, in tetragonal phase with an average particle size of ~7 nm and a large surface area of 340 m² g^?1. The equilibrium sorption capacity of t-ZrO₂ is >250 mg Mo g^?1. The present study indicates that ⁹⁹Mo is both strongly and selectively retained by t-ZrO₂ at acidic pH and ^99mTc could be readily eluted from it, using 0.9% NaCl solution. A 9.25 GBq (250 mCi) t-ZrO₂ based chromatographic ⁹⁹Mo/^99mTc generator was developed and its performance was repeatedly evaluated for 10 days. ^99mTc could be eluted with >85% yield having acceptable radionuclidic, radiochemical and chemical purity for clinical applications. The compatibility of the product in the preparation of ^99mTc labeled formulations such as ^99mTc-EC and ^99mTc-DMSA was evaluated and found to be satisfactory.     

Perfect polar stacking of parallel beloamphiphile layers. Synthesis, structure and solid-state optical properties of the unsymmetrical acetophenone azine DCA

Extraordinary high degrees of polar order can be achieved by a rational design that involves the polar stacking of parallel beloamphiphile monolayers (PBAM). This strategy is exemplified by the acetophenone azines MCA (4-methoxy-4'-chloroacetophenone azine) and DCA (4-decoxy-4'-chloroacetophenone azine). The beloamphiphile design aims to achieve strong lateral interactions by way of arene-arene, azine-azine, arene-azine and halogen-bonding interactions. Dipole-induced interactions and halogen bonding dominate interlayer interactions and halogen bonding is shown to effect the layer stacking. Crystals of DCA contain PBAMs with perfect polar order and perfect polar layer stacking, while crystals of MCA features perfect polar order only in one of two layers and layer stacking is polar but not entirely perfect. We report the synthesis of the beloamphiphile DCA, its crystal structure, and we present a comparative discussion of the structures and intermolecular interactions of MCA and DCA. Absorbance and photoluminescence measurements have been carried out for solutions of DCA and for DCA crystals. DCA exhibits a broad emission centered at 2.5 eV when excited with UV radiation. The nonlinear optical response was studied by measuring second harmonic generation (SHG). Strong SHG signals have been observed due to the polar alignment and the DCA crystal's NLO response is 34 times larger than that of urea. Optimization of the beloamphiphile and systematic SAR studies of the polar organic crystals, which are now possible for the very first time, will further improve the performance of this new class of functional organic materials. The materials are organic semiconductors and show promise as blue emitters, as nonlinear optical materials and as OLED materials.     

Concise and Simple Synthesis of M1 Allosteric Agonist TBPB

A concise and simple synthesis of M₁ allosteric agonist 1-(1′-(2-methylbenzyl)-1,4′-bipiperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one (TBPB) using economical and commercially available orthophenylenediamine (O-PDA) and Boc piperidone has been described. The disclosed scheme allows synthesizing more analogs that were otherwise difficult to prepare with the original method.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Liquid crystalline behaviour of mixtures of structurally dissimilar mesogens in binary systems

We have studied four binary systems comprising four ester components, viz. 4-nitrophenyl-4′-n-alkoxybenzoates (wheren-alkoxy isn-butoxy, C₄,n-hexyloxy, C₆,n-octyloxy, C₈ andn-decyloxy, C₁₀) and one azo component, 4-n-decyloxy phenylazo-4′-isoamyloxy benzene. A variety of mesomorphic properties are observed in these mixtures. The properties of these systems are discussed on the basis of phase diagrams.     

Propargyl alcohols as β-oxocarbenoid precursors for the ruthenium-catalyzed cyclopropanation of unactivated olefins by redox isomerization

An atom-economical method for the direct synthesis of [3.1.0]- and [4.1.0]-bicyclic frameworks via Ru-catalyzed redox bicycloisomerization of enynols is reported. The presented results highlight the unique reactivity profile of propargyl alcohols, which function as β-oxocarbene precursors, in the presence of a ruthenium(II) complex. Furthermore, a rare case of a formal vinylic C-H insertion reaction is described.     

Studies on the adsorption of <Superscript>125</Superscript>I on bromide coated silver rods for the preparation of <Superscript>125</Superscript>I-seeds for brachytherapy applications

This article presents the development, the testing and the efficiency estimation of a system for the monitoring of the atmospheric concentration of radon using a detector ionization chamber type in pulse mode for environmental measurements in which the measurement of the average value of the ionization current is completed with the recording of the impulses of the ionization current caused by the alpha disintegrations from the sensible volume of the detector.     

Mesoporous and biocompatible surface active silica aerogel synthesis using choline formate ionic liquid

In this paper, we report the preparation and characterization of mesoporous and biocompatible transparent silica aerogel by the sol-gel polymerization of tetraethyl orthosilicate using ionic liquid. Choline cation based ionic liquid allows the silica framework to form in a non collapsing environment and controls the pore size of the gel. FT-IR spectra reveal the interaction of ionic liquid with surface -OH of the gel. DSC thermogram giving the evidence of confinement of ionic liquid within the silica matrix, which helps to avoid the shrinkage of the gel during the aging process. Nitrogen sorption measurements of gel prepared with ionic liquid exhibit a low surface area of 100.53 m2/g and high average pore size of 3.74 nm. MTT assay proves the biocompatibility and cell viability of the prepared gels. This new nanoporous silica material can be applied to immobilize biological molecules, which may retain their stability over a longer period.