Experimental measurement and correlation of flash point of alternate PUREX/UREX solvent (36% TiAP) in C<Subscript>8</Subscript>–C<Subscript>16</Subscript> diluents

Flash point of a chemical characterizes its operating safety envelope. Tri-isoamyl phosphate (TiAP) is being proposed as an alternate to conventional nuclear solvent tri-n-butyl phosphate but flash point of TiAP containing organic solutions are not available in literature. Flash points of C₈–C₁₆ n-alkanes and 36% TiAP/C₈–C₁₆ n-alkane solutions were experimentally measured and correlated by means of empirical correlations. This paper is probably the first reported work in the literature on flash points of TiAP containing solutions.     

An efficient stereoselective route to the construction of tricyclic core structure towards the synthesis of the sesquiterpenes of the seco-prezizaane family

An efficient stereoselective approach to the construction of a hydrindane derivative having a bridged lactone is described toward the synthesis of the sesquiterpenes of the seco-prezizaane family. The key step involves RO-RCM of a norbornene derivative.     

Synthesis of a Mn6 cluster and its self-assembly of an azido-bridged polymer

A rare micro6-oxo-centered Mn6 mixed-valent cluster (1) is prepared and used as a secondary building unit for the self-assembly of its azido-bridged polymeric analogue (2) in a systematic way with the retention of the Mn6 core of 1. Both complexes are characterized by X-ray single-crystal structure determination. The complex 1 was crystallized in a monoclinic system, space group P21, a=11.252(5) A, b=20.893(9) A, c=12.301(6) A, and beta=115.853(7) degrees, whereas the polymeric analogue 2 was crystallized in an orthorhombic system, space group P212121, a=13.1941(8) A, b=14.9897(9) A, and c=27.8746(14) A. Variable-temperature magnetic behavior showed the presence of strong antiferromagnetic interaction in both cases.     

Evaluation of hepatoprotective activity of aqueous extracts of leaves of Basella alba in albino rats

This study was done to evaluate possible hepatoprotective effects of aqueous leaf extracts of Basella alba in comparison with silymarin in paracetamol-induced hepatotoxicity in albino rats. Six groups of six albino rats each received orally for 6 weeks, vehicle, paracetamol (2 g/kg/day), paracetamol (2 g/kg/day) plus silymarin (50 mg/kg/day), paracetamol (2 g/kg/day) plus B. alba extract (60 mg/kg/day), paracetamol (2 g/kg/day) plus B. alba extract (80 mg/kg/day) and paracetamol (2 g/kg/day) plus B. alba extract (100 mg/kg/day). Hepatoprotective effect was evaluated by comparing serum bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, proteins, alkaline phosphatase and liver histopathology. Results were represented as mean ± SEM. One-way ANOVA was done followed by post hoc Tukey's test with a highly significance level of P < 0.001. Aqueous leaf extracts of B. alba 100 mg/kg/day orally had significant hepatoprotective effect in paracetamol-induced hepatotoxicity in albino rats. The results were well comparable and even in some respects superior to standard drug silymarin.     

Syntheses, structures, spectroscopic, electrochemical properties and DFT calculation of Ru(II)–thioarylazoimidazole complexes

The reaction of 1-alkyl-2-{(o-thioalkyl)phenylazo}imidazoles (SRaaiNR) (2a/2b) with Ru(II) has synthesized [Ru(SRaaiNR)₂](ClO₄)₂ (3a/3b) in 2-methoxyethanol. The reaction in methanol, however, has synthesized [Ru(SRaaiNR)(SRaaiNR)Cl](ClO₄) (4a/4b). The solid phase reaction of SRaaiNR and RuCl₃ on silica gel surface upon microwave irradiation has synthesized [Ru(SRaaiNR)(SaaiNR)](PF₆) (5a/5b) [SRaaiNR represents tridentate N,N′,S-chelator; SRaaiNR is N,N′-bidentate chelator where S does not coordinate and SaaiNR refers N,N′,S-chelator where S refers to thiolato binding]. The structural characterization of [Ru(SEtaaiNEt)(SEtaaiNEt)Cl](ClO₄) (4b) and [Ru(SEtaaiNEt)(SaaiNEt)](PF₆) (5b) has been confirmed by single crystal X-ray diffraction study. The IR, UV–Vis, and ¹H NMR spectral data also support the stereochemistry of the complexes. The complexes show metal oxidation, Ru(III)/Ru(II), and ligand reductions (azo/azo⁻, azo⁻/azo). The molecular orbital diagram has been drawn by density functional theory (DFT) calculation. Normal mode of analysis has been performed to correlate calculated and experimental frequencies of representative complexes. The electronic movement and assignment of electronic spectra have been carried out by TDDFT calculation both in gas and acetonitrile phase.     

Organocatalytic Strategies for the Synthesis of Cyclopenta‐Fused Arenes and Heteroarenes

Cyclopentanoids are omnipresent in natural products and pharmaceutically relevant compounds. Among them, cyclopenta‐fused arenes and heteroarenes possess impressive biological properties and play significant role in materials science. Consequently, several notable methods have been developed for their synthesis over the years. In this review, we mainly described metal‐free and organocatalytic approaches that led to the construction of pentannulated arenes and heteroarenes.     

Synthesis,SAR and in vitro therapeutic potentials of thiazolidine-2,4-diones

Background

Thiazolidinedione is a pentacyclic moiety having five membered unsaturated ring system composed with carbon, oxygen, nitrogen and sulfur molecules at 1 and 3 position of the thiazole ring and widely found throughout nature in various form. They favourably alter concentration of the hormones secreted by adipocytes, particularly adiponectin. They also increase total body fat and have mixed effects on circulating lipids. Thiazolidinedione nucleus is present in numerous biological moieties and has different pharmacological activities likes, e.g. antimalarial, antimicrobial, antimycobacterial, anticonvulsant, antiviral, anticancer, anti-inflammatory, antioxidant, anti-HIV (human immunodeficiency virus) and antituberculosis.

Results and discussion

The synthesized compounds were screened for their in vitro antimicrobial potential against Gram (positive and negative) bacterial and fungal strains by tube dilution technique. In this series, compound 10 exhibited significant antimicrobial activity against B. subtilis and S. aureus with MIC?=?4.2?×?10^?2 µM/ml, compound 15 showed significant activity against K. pneumonia with MIC?=?2.60?×?10^?2 µM/ml and compound 4 displayed potent antibacterial activity against E. coli with MIC?=?4.5?×?10^?2 µM/ml. Compound 10 had most potent antifungal activity against C. albicans and A. niger with MIC?=?4.2?×?10^?2 µM/ml. Compounds 12 and 15 were found as most active antidiabetic agents having IC₅₀?=?27.63 μg/ml and 22.35 μg/ml, respectively, using DPPH assay. Antioxidant activity results indicated that compounds 3 and 9 displayed good antioxidant agent with IC₅₀?=?29.04 μg/ml and 27.66 μg/ml respectively, using α amylase assay.

Conclusion

All the synthesized derivatives exhibited good antimicrobial, antidiabetic and antioxidant activities using specific methods then compared with mentioned standard drugs. Especially, compounds 3, 4, 9, 10, 12 and 15 displayed highest activity. Structure activity relationship demonstrated that presence of electron withdrawing group (o-NO₂, p-Cl, p-Br) enhanced the antibacterial activity against E. coli as well as increased the antioxidant activity while the presence of electron releasing group (o/p-OCH₃, 3,4,5-trimethoxy) enhanced the antibacterial activity against S. aureus, B. subtilis, S. typhi, K. pneumonia, C. albicans and A. niger as well as the antidiabetic activity.

     

Cyclopentadienyl Complexes of the Alkaline Earths in Light of the Periodic Trends

The electron-rich cyclopentadienyl and the analogous indenyl and fluorenyl ligands (collectively denoted here as Cp’) have been impactful in stabilizing electron-deficient metal centers including the highly electropositive alkaline earths. Being in the s-block, the group 2 metals follow a major periodic variation in their atomic and ionic properties which is reflected in those Cp’ compounds. This article presents an overview of this class of compounds for all the five metals from beryllium to barium (radium is excluded for its radioactivity), highlighting their systematic variation.     

Enthalpy changes in oxidative addition reactions of iodine with monomeric and dimeric rhodium(I) complexes

The heat of reaction for addition of iodine to the planar complexes RhCl(CO)dppe, Rh(dppen)₂⁺, Rh(dppe)₂⁺ and to the dimer Rh₂Cl₂(CO)₂(dppm)₂ has been obtained by a calorimetric method. Iodine forms stronger Rh---I bonds with RhCl(CO)dppe than with the bichelate complexes. The presence of metal-metal interaction in the iodine addition compound of Rh₂Cl₂(CO)₂(dppm)₂ makes a significant contribution to the enthalpy change for the oxidative addition. The stereochemistry of the complexes are discussed on the basis of IR and ³¹P NMR spectra.     

Molecular Topology Tuning of Bipolar Host Materials Composed of Fluorene‐Bridged Benzimidazole and Carbazole for Highly Efficient Electrophosphorescence

Two new molecules, CzFCBI and CzFNBI , have been tailor‐made to serve as bipolar host materials to realize high‐efficiency electrophosphorescent devices. The molecular design is configured with carbazole as the hole‐transporting block and N‐phenylbenzimidazole as the electron‐transporting block hybridized through the saturated bridge center (C9) and meta‐conjugation site (C3) of fluorene, respectively. With structural topology tuning of the connecting manner between N‐phenylbenzimidazole and the fluorene core, the resulting physical properties can be subtly modulated. Bipolar host CzFCBI with a C connectivity between phenylbenzimidazole and the fluorene bridge exhibited extended π conjugation; therefore, a low triplet energy of 2.52 eV was observed, which is insufficient to confine blue phosphorescence. However, the monochromatic devices indicate that the matched energy‐level alignment allows CzFCBI to outperform its N‐connected counterpart CzFNBI while employing other long‐wavelength‐emitting phosphorescent guests. In contrast, the high triplet energy (2.72 eV) of CzFNBI imparted by the N connectivity ensures its utilization as a universal bipolar host for blue‐to‐red phosphors. With a common device configuration, CzFNBI has been utilized to achieve highly efficient and low‐roll‐off devices with external quantum efficiency as high as 14 % blue, 17.8 % green, 16.6 % yellowish‐green, 19.5 % yellow, and 18.6 % red. In addition, by combining yellowish‐green with a sky‐blue emitter and a red emitter, a CzFNBI ‐hosted single‐emitting‐layer all‐phosphor three‐color‐based white electrophosphorescent device was successfully achieved with high efficiencies (18.4 %, 36.3 cd A^?1, 28.3 lm W^?1) and highly stable chromaticity (CIE x=0.43–0.46 and CIE y=0.43) at an applied voltage of 8 to 12 V, and a high color‐rendering index of 91.6.