Partitioning of quencher ions in the micellar microenvironment of polyoxyethylene nonyl phenol

This paper has explored the quenching of fluorescence of the dye safranine T (ST) by the inorganic cations viz Cu2+, Co2+, Ni2+ and Mn2+ in micellar solutions of the surfactant dioxyethylene nonyl phenol (Igepal CO-210), pentaoxyethylene nonyl phenol (Igepal CO-520) and dodecaoxyethylene nonyl phenol (Igepal CO-720). The quenching results have been calculated in light of stern volmer equation (SV) to evaluate the extent of interaction between the fluorophore (ST) and quencher. The average concentration of the quencher ions in the micelle have been determined. The quenching efficiency of ST by inorganic ions in micellar medium is lower than that in aqueous medium. The results show that the ions get partitioned in the micellar medium. The values of the partition coefficient of the ions decrease with increase in HLB value and number of oxyethylene groups in Igepal.     

Formation andstability of magnetic moment on isolated Rh impurities in dilute PtFe alloys

The local susceptibilities (T) of isolated Rh impurities in paramagnetic dilute Pt(Fe) alloys have been measured using the TDPAC method. The results show existence of 4d magnetic moment for Rh with reduced spin fluctuation temperatures (T _sf). It is suggested that moment stability scaled byT _sf is governed mainly by the interatomic d-d exchange interaction caused by induced ferromagnetic polarization of host d band electrons.     

Cationic vesicles as chiral selector for enantioseparations of nonsteroidal antiinflammatory drugs by micellar electrokinetic chromatography

A vesicle-forming chiral cationic surfactant (1R,2S)-(-)-N-dodecyl-N-methyl-ephedrinium bromide was evaluated as a pseudo-stationary phase in micellar electrokinetic chromatography (MEKC) for enantioseparation of eight non-steroidal anti-inflammatory drugs e.g., carprofen, flurbiprofen, fenoprofen, ibuprofen, indoprofen, ketoprofen, naproxen and suprofen by capillary electrophoresis. The effects of varying experimental conditions such as pH and concentration of surfactant in the running buffer on the enantiomer separation of the drugs are reported. A mixture of five of the above drugs was separated and each enantiomeric pair was also separated simultaneously in a single run by use of the surfactant. The strong electrostatic interactions between the analytes and the vesicles seemed to have a major role in the enantiomeric separation of the profens.     

Natures of Statefinder Parameters and Om Diagnostic for Cardassian Universe in Ho?ava-Lifshitz Gravity

In this work, we have considered Cardassian Universe in Ho?ava-Lifshitz gravity. Four types of Cardassian Universe models i.e., polytropic/power law, modified polytropic, exponential and modified exponential models have been considered for accelerating models. The natures of statefinder parameters, deceleration parameter, Om diagnostic and EoS parameters have been investigated for all types of Cardassian models in Ho?ava-Lifshitz gravity.     

Chemical Composition of Essential Oil from Pilea microphylla and its Antimicrobial Activity

Chemistry of Natural Compounds -     

Effect of seasonal variation on dust samples of a winter fog affected urban environment of India,South East Asia

Physical and chemical characteristics of leaf dust (LD) samples, collected between 2011 and 2013, of a severely winter fog affected and polluted urban environment (Allahabad, India) of Indo-Gangetic plain are presented in this study. The weather changes in the study area are grouped into three effective annual seasonal periods – winter fog, pre-monsoon and post-monsoon. The pronounced impact of seasonal variations is observed in LD characteristics, as ~46% of the winter fog period samples ranges in size between 2.5 and 20 µm with high magnetic susceptibility (up to 938.22 × 10^?8 m³ kg^?1). In comparison, 35% of the LD from pre-monsoon period occurs in the size range of 100–300 µm with low magnetic susceptibility (up to 43.29 × 10^?8 m³ kg^?1). The fractal analysis involving submicroscopic clast dimension of LD also reveals a seasonal influence. The toxic metals (Pb, Zn, Cd, Cr and Ni) in LD belonging to winter fog and post-monsoon periods increase in comparison to samples from pre-monsoon time. Multivariate statistical analysis of trace element data suggests that the LD collected from winter fog and post-monsoon periods originate predominantly from anthropogenic source, whereas those collected during pre-monsoon owe their origin to crustal and anthropogenic sources, mainly. The present study has demonstrated the role of seasonal variation in controlling the physical and chemical properties of particulate matter based on multiple parameter analyses, and the derivation of the dust load from a mixed source (upper continental crust, anthropogenic and vehicular) for the study area for the first time.     

Dynamics of Logamediate and Intermediate Scenarios in the Dark Energy Filled Universe

We have considered a model of two component mixture i.e., mixture of Chaplygin gas and barotropic fluid with tachyonic field. In the case, when they have no interaction then both of them retain their own properties. Let us consider an energy flow between barotropic and tachyonic fluids. In both the cases we find the exact solutions for the tachyonic field and the tachyonic potential and show that the tachyonic potential follows the asymptotic behavior. We have considered an interaction between these two fluids by introducing a coupling term. Finally, we have considered a model of three component mixture i.e., mixture of tachyonic field, Chaplygin gas and barotropic fluid with or without interaction. The coupling functions decays with time indicating a strong energy flow at the initial period and weak stable interaction at later stage. To keep the observational support of recent acceleration we have considered two particular forms (i) Logamediate Scenario and (ii) Intermediate Scenario, of evolution of the Universe. We have examined the natures of the recent developed statefinder parameters and slow-roll parameters in both scenarios with and without interactions in whole evolution of the universe.     

Anomalous excited-state dynamics of lucifer yellow CH in solvents of high polarity: evidence for an intramolecular proton transfer

The photophysics of the fluorescent probe Lucifer yellow CH has been investigated using fluorescence spectroscopic and computational techniques. The nonradiative rate is found to pass through a minimum in solvents of intermediate empirical polarity. This apparently anomalous behavior is rationalized by considering the possibility of predominance of different kinds of nonradiative processes, viz. intersystem crossing (ISC) and excited-state proton transfer (ESPT), in solvents of low and high empirical polarity, respectively. The feasibility of the proton transfer is examined by the structure determined by the density functional theory (DFT) calculations. The predicted energy levels based on the time-dependent density functional theory (TD-DFT) method in the gas phase identifies the energy gap between the S(1) and nearest triplet state to be close enough to facilitate ISC. Photophysical investigation in solvent mixtures and in deuterated solvents clearly indicates the predominance of the solvent-mediated intramolecular proton transfer in the excited state of the fluorophore in protic solvents.     

Catalytic Asymmetric Epoxidation of Aldehydes with Two VANOL‐Derived Chiral Borate Catalysts

A highly diastereo‐ and enantioselective method for the epoxidation of aldehydes with α‐diazoacetamides has been developed with two different borate ester catalysts of VANOL. Both catalytic systems are general for aromatic, aliphatic, and acetylenic aldehydes, giving high yields and inductions for nearly all cases. One borate ester catalyst has two molecules of VANOL and the other only one VANOL. Catalysts generated from BINOL and VAPOL are ineffective catalysts. An application is shown for access to the side‐chain of taxol.