Structural, energetic, electronic, bonding, and vibrational properties of Ga3O, Ga3O2, Ga3O3, Ga2O3, and GaO3 clusters

The results of density functional theory based calculations on Ga3O, Ga3O2, Ga3O3, Ga2O3, and GaO3 clusters are reported here. A preference for planar arrangement of the constituent atoms maximizing the ionic interactions is found in the ground state of the clusters considered. The sequential oxidation of the metal-excess clusters increases the binding energy, but the sequential removal of a metal atom from the oxygen-excess clusters decreases the binding energy. The increase in the oxygen to metal ratio in these clusters is accompanied by increase in both electron affinity and ionization potential. The ionization induced structural distortions in the neutral clusters are relatively small, except those for Ga3O2. In anionic (cationic) clusters, the added (ionized) electron is shared by the Ga atoms, except in the case of GaO3. The vibrational frequencies and charge density analysis reveal the importance of the ionic Ga-O bond in stabilizing the gallium oxide clusters considered in this study.     

Simultaneous Determination of Diclofenac Sodium and Rabeprazole Sodium in Bulk and Pharmaceutical Dosage Form by LC

A simple, selective, rapid, precise and accurate reverse phase high pressure liquid chromatographic method has been developed for the simultaneous estimation of diclofenac sodium and rabeprazole sodium from pharmaceutical formulations. The method was developed using a HiQ SiL C18 (250 mm × 4.6 mm i.d.) column with a mobile phase consisting of methanol:water, (80:20 v/v), at a flow rate of 1.25 mL min^?1. Detection was carried out at 284 nm. Indapamide was used as an internal standard. The developed method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed method can be used for the estimation of these drugs in combined dosage forms.     

A theoretical study of electronic and vibrational properties of neutral,cationic, and anionic B24 clusters

The equilibrium geometries, electronic and vibrational properties, and static polarizability of B₂₄, B, and B clusters are reported here. First‐principles calculations based on density functional theory predict the staggered double‐ring configuration to be the ground state for B₂₄, B, and B, in contrast to the quasi‐planar structure observed in small neutral and ionized B_n clusters with n ≤ 15. Furthermore, the (4 × B₆) tubular structure is found to be relatively stable in comparison to the 3D cage structure. The presence of delocalized π and multicentered σ bonds appears to be the cause of the stability of the double‐ring and tubular isomers. For the ground state of B₂₄, the lower and upper bound of the electron affinity is 2.67 and 2.81 eV, respectively, and the vertical ionization potential is 6.88 eV. Analysis of the frequency spectrum of the double‐ring and tubular isomers reveals the characteristic vibrational modes typically observed in carbon nanotubes. The corresponding IR spectrum also reflects the presence of some of these characteristic modes in the neutral and ionized B₂₄, suggesting that double‐ring and tubular structures can be considered as the building blocks of boron nanotubes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Stipulating Low Production Cost Solar Cells All Set to Retail…!

Today's solar cells are exceptionally in demand whilst excess exploitation of natural fossil fuels. In this context, the first and second generation solar cells commercially available in market for more than decades however limitations in production cost and large–scale applications insist to generate inexpensive materials for fabrication. Thereby, organic materials based solar cells explored and emerging as third generation solar cells which possess flexibility, low cost and large‐scale applications. For example, organic photovoltaics, dye sensitized solar cells and perovskite (organic‐inorganic) solar cells (PSCs) are considered third generation solar cells wherein PSCs reached the record power conversion efficiency (PCE ～23 %) and durability assists great advantages for commercialization in near future. Moreover, we reported various global renowned companies involved producing the modules and materials for three generation solar cells, hence, majority of companies considered commercialization of perovskite based solar cells assist low cost photovoltaics to meet the current energy necessities and environmental safety.     

Voltage Stimulated Anion Binding of Metalloporphyrin‐induced Crystalline 2D Nanoflakes

Voltage‐stimulated redox‐active materials have received significant attention in the field of organic electronics and sensor technology. Such stimuli‐responsive materials trigger the formation of crystalline nanostructures and facilitate the design of efficient smart devices hitherto unknown. Herein, we report that free‐base and metallo‐tetratolylporphyrin‐linked ferrocene derivatives ( H₂TTP ‐ Fc and ZnTTP ‐ Fc ) undergo distinct proton/anion binding mechanism in CHCl₃ during bulk electrolysis at applied voltage of 1.4 V to give [ H₄TTP ‐ Fc]⁺Cl^? and H⁺ [ (Cl)ZnTTP ‐ Fc]^? followed by nanospheres and crystalline 2D nanoflakes formation, confirmed by SEM and TEM images, by methanol vapor diffusion (MVD) approach. Moreover, X‐ray diffraction analysis suggest that protonated H₂TTP ‐ Fc aggregates exhibit amorphous nature, whereas H⁺ [ (Cl)ZnTTP ‐ Fc]^? depict crystalline nature from layer‐by‐layer arrangement of nanoflakes assisted by π–π stacking and ion‐dipole interactions.     

Structural and optical characteristics of Ce,Nd, Gd,and Dy-doped $$\hbox {Al}_{2}\hbox {O}_{3}$$ thin films

In a quantum harmonic oscillator (QHO), the energy of the oscillator increases with increased frequency. In this paper, assuming a boundary condition that the product of momentum and position, or the product of energy density and position remains constant in the QHO, it is established that a particle subjected to increasing frequencies becomes gradually subtler to transform into a very high dormant potential energy. This very high dormant potential energy is referred to as ‘like-potential’ energy in this paper. In the process a new wave function is generated. This new function, which corresponds to new sets of particles, has scope to raise the quantum oscillator energy (QOE) up to infinity. It is proposed to show that this high energy does not get cancelled but remains dormant. Further, it is proposed that the displacement about the equilibrium goes to zero when the vibration of the oscillator stops and then the QOE becomes infinity – this needs further research. The more the QOE, the greater will be the degree of dormancy. A simple mathematical model has been derived here to discuss the possibilities that are involved in the QHO under the above-mentioned boundary conditions.