A Novel Chemo‐selective Epoxidation across Acrylate Ester: Synthesis of New Water‐Soluble Forskolin Analogues

While removing the TBDMS group from OH protection, a novel epoxidation reaction occurred across acrylate ester attached to a forskolin fragment. Besides spectroscopic data, the epoxide formation was confirmed by ring opening with a secondary amine. This unique epoxidation reaction, to our knowledge, is not known in the literature. This reaction led us to discover a simple deblocking protocol. The epoxide and the desired Michael substrates were used to introduce imidazole into forskolin.     

Surface modification of semiconductor photoelectrodes for better photoelectrochemical performance

The present paper describes the modification and solar hydrogen production studies employing a new semiconductor-septum (SC-SEP) photoelectrode ns-TiO₂/In₂O₃ based photoelectrochemical solar cell. The current-voltage characteristics of the above SC-SEP cell revealed that an enhancement in short-circuit current (I_SC) up to three times (5 ～ 14.6 mA cm^?2). The optimum hydrogen production rate was found to be 11.8 lh^?1 m^?2 for 5M H₂SO₄ and with a further increase in H₂SO₄ concentration, the hydrogen production rate was found to be invariant. In yet another part of our study instead of using new SC-SEP solar cell design, we used another new oxide material form such as ns-TiO₂/WO₃. The ns-TiO₂/WO₃ exhibited a high photocurrent and photo-voltage of 15.6 mA cm^?2, 960 mV, respectively. The ns-TiO₂/WO₃ electrode exhibited a higher hydrogen gas evolution rate of 13.8 lh^?1 m^?2. Evidences and arguments are put forward to show that, whereas for the bare ns-TiO₂ electrode, the improvement in the performance of this photo-electrode compared with its original form was due to the higher quantum yield. In the case of ns-TiO₂/In₂O₃ and ns-TiO₂/WO₃ photo-electrodes, the improvement is due to the improved spectral response resulting from decrease of energy band gap.     

Heterobimetallic dioxomolybdenum(VI) complexes derived from bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone: Synthesis and characterization

The heterobimetallic complexes [MMoO₂(L)(H₂O)₂] (where M = Zn²⁺ (1), Cu²⁺ (2), and Co²⁺ (4)) and [{MMoO₃(H₂L)(H₂O)₂}₂] (where M = Ni²⁺ (3) and Mn²⁺ (5)) are synthesized from bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (H₄L) using the monometallic precursor complex [MoO₂(H₂L)]·H₂O in ethanol. The composition of the complexes is established based on the data obtained from the elemental analysis and molecular weight determinations. The structure of the complexes is discussed in the light of data obtained from molar conductance, magnetic moment, electronic, EPR and IR spectroscopic studies.     

Synthesis and Characterization of Some Heteroaromatic Derivatives of 3‐But‐2‐enoyl‐chromen‐2‐one and Their Potential as Anti‐inflammatory Agents

A novel series of chromen‐2‐ones containing pyrazole, isoxazole, oxazine, and thiazine substitutions have been synthesized by reacting 3‐[3‐(4‐chloro‐phenyl)‐acryloyl]‐chromen‐2‐one and 3‐[3‐(3‐methoxy‐phenyl)‐acryloyl]‐chromen‐2‐one with various cyclizing agents such as hydrazine, phenylhydrazine, urea, and thiourea. The structures of all the synthesized compounds were confirmed by the use of IR, ¹H‐NMR, mass spectroscopy, and elemental analysis data. All the newly synthesized compounds were evaluated for their anti‐inflammatory activity at a dose of 100 mg/kg body weight in carrageenan‐induced rat paw edema model. The entire series of the compounds exhibited moderate to good anti‐inflammatory activity, with the percentage inhibition of edema formation ranging from 39.99 to 63.15 against the reference drug ibuprofen (100 mg/kg) that showed 78.96% inhibition at the third hour. Compounds 3a , 3c , and 3d showed good inhibitory activity, whereas compounds 3b , 3e , 3f , and 3j showed moderate inhibitory activity at the third hour.     

Studies on the partitioning of actinides from high level liquid waste solution employing supported liquid membrane with Cyanex-923 as carrier

The present paper deals with the studies on the partitioning of actinides from high level liquid waste solution of PUREX origin employing supported liquid membrane technique. The process uses solution of Cyanex-923 in n-dodecane as a carrier with poly tetra fluoro ethylene support and a mixture of citric acid, formic acid and hydrazine hydrate as a receiving phase. Transport studies are carried out for ²⁴¹Am under different experimental conditions to optimize the transport parameters such as feed acidity, carrier concentration, effect of uranium, trivalent metal ion and salt concentration in the feed. Studies indicated good transport of actinides across the membrane from nitric acid medium. Under the optimized conditions the transport of ²⁴¹Am is studied from a uranium depleted synthetic PHWR-HLLW and finally the technique has been used for the partitioning of alpha emitters from an actual research reactor-HLLW. High concentration of uranium in the feed is found to retard the transport of americium, suggesting the need for prior removal of uranium from the waste.     

Carrier facilitated transport of thorium from HCl medium using Cyanex 923 in n-dodecane containing supported liquid membrane

Present studies deal with supported liquid membrane (SLM) technique for the separation of thorium from hydrochloric acid (HCl) medium using Cyanex 923 as a carrier. Effects of feed acidity, strippant, and membrane pore size and membrane thickness on the transport of thorium have been studied in detail. The optimized parameters were applied for separation of thorium from a radioanalytical waste. Stability of the membrane and membrane support was investigated. Transport of thorium increased from 78.3 to about 93.7 % with increase in acidity from 0.5 to 2 M using 0.3 M Cyanex 923 in n-dodecane as carrier and 2 M ammonium carbonate as stripping phase. The transport of thorium decreased above 2 M HCl. An attempt was made to model the physicochemical transport of thorium in SLM and understand the mechanism of thorium transport.     

Enhanced dielectric and electro-optical properties of a newly synthesised ferroelectric liquid crystal material by doping gold nanoparticle-decorated multiwalled carbon nanotubes

In this article, a newly synthesised ferroelectric liquid crystal (FLC) material, namely LAHS 22, has been characterised. The characterisation of the FLC material has been performed using dielectric relaxation spectroscopy, differential scanning calorimetry and polarisation optical microscopy. We observed an enhancement in the dielectric and electro-optical properties of the FLC material by incorporating gold nanoparticles (GNPs)-decorated multiwalled carbon nanotubes (MWCNTs). The GNPs-decorated MWCNTs cause an increment in dielectric dispersion (up to kHz), absorption, spontaneous polarisation and rotational viscosity of the FLC material. The pure and GNPs-decorated MWCNTs doped FLC cells were analysed by means of various dielectric spectroscopic and optical measurements. The observed enhancement in the dielectric and electro-optical properties of the FLC material has also been studied with concentration of GNPs-decorated MWCNTs in FLC material. The GNPs-decorated MWCNTs/FLC composites are not only of fundamental importance, but also useful materials for device applications such as liquid crystal displays and memory devices.     

Blue phase III widening in CE6-dispersed surface-functionalised CdSe nanoparticles

The phase transition behaviour of the chiral liquid crystal CE6 doped with spherical surface-functionalised CdSe nanoparticles has been examined by means of high-resolution adiabatic scanning calorimetry and polarising microscopy. The addition of nanoparticles results in an essentially stabilised blue phase III. The phase diagram is displayed upon heating and cooling and the enthalpy changes involved in the conversion between the blue phases are determined. The dispersion of functionalised nanoparticles is prominent for the stabilisation of blue phase III, which is potentially useful for applications, especially if applied on liquid crystals that exhibit blue phases close to room temperature.     

Visible-light-promoted aerobic oxidative cyclization to access 1,3,4-oxadiazoles from aldehydes and acylhydrazides

A novel and practical access to symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles directly from aldehydes and acylhydrazides using visible light irradiation under an air atmosphere in the presence of eosin Y as an organophotoredox catalyst at rt is reported. This is the first example of oxidative cyclization of acylhydrazones employing air and visible light as inexpensive, readily available, non-toxic, and sustainable reagents.     

Nitro‐Substituted Bishomocubanes: Synthesis,Characterization, and Application as Energetic Materials

Several high‐energy‐density strained polycyclic compounds nitromethyl‐l,3‐bishomocubane (NMBHC), nitromethylene‐1,3‐bishomocubane (NMyBHC), and bis(nitromethyl)‐1,3‐bishomocubane (DNTMBHC), which were synthesized for the first time from bishomocubanone, hold potential for application as standalone fuels in liquid bipropellant systems or as additives in liquid and solid propellant formulations. DFT analysis at the B3LYP/6‐31G(d) level of theory was employed to optimize the geometries of the compounds and to determine their densities, heats of formation, and various thermodynamic properties. The density specific impulse, determined by using equilibrium thermodynamics, demonstrated an improvement of 75 s for NMBHC and NMyBHC over standard hydrocarbons. The specific impulse with ammonium perchlorate showed an improvement of 25–30 s over hydroxy‐terminated polybutadiene. Thermogravimetric analysis revealed that NMBHC, NMyBHC, and DNTMBHC evaporated readily with activation energies of 58.8, 69.2, and 74.5 kJ mol^?1, respectively.