The extraction of ammine complexes of Cu²⁺, Cd²⁺, Ni²⁺, Co²⁺ and Zn²⁺ by synthesised manganese, nickel and zinc silicates has been studied at different pH and ionic concentrations in the external solution. It has been found that the uptake of the metal ion Co²⁺, Cu²⁺ and Zn²⁺ increases with increase in pH of the external solution, attains a maximum and then decreases. However, the uptake for Cd²⁺ and Ni²⁺ increases continuously. The q_A values of all the silicates increases with the increase in the concentration of the exchanging ion and its order for the investigated metal ions is Ni²⁺ < Co²⁺ < Cd²⁺ < Zn²⁺ < Cu²⁺.

We investigate the properties of GaN semiconducting nanoparticles as a potential candidate for photodetection in the solar-blind region. The photocurrent spectral response is studied spanning the range 1.6-5.5 eV. A significant fraction of the response is in the range 4–5.5 eV. The results are compared to other optical properties and the origins of the features observed in the spectra are speculated upon.

Disordered Sr₂FeMoO₆ shows a drastic reduction in saturation magnetization compared to highly ordered samples, moreover magnetization as a function of the temperature for different disordered samples shows qualitatively different behaviours. We investigate the origin of such diversity by performing spatially resolved photoemission spectroscopy on various disordered samples. Our results establish that e_xtensive electronic inhomogeneity, arising most probably from an underlying chemical inhomogeneity in disordered samples, is responsible for the observed magnetic inhomogeneity. It is further pointed out that these inhomogeneities are connected with composition fluctuations of the type Sr₂Fe_1+xMo_1-xO₆ with Fe-rich (x > 0) and Mo-rich (x < 0) regions.

Polystyrene-anchored Cu(II), Zn(II), Cd(II), Ni(II), Mn(II), MoO₂(II), UO2(II), Fe(III) and Zr(IV), complexes of the unsymmetrical dibasic tetradentate ONNO donor Schiff base derived from the condensation of chloromethylated polystyrene, 3-formylsalicylic acid, ethylenediamine and 2-benzoylacetanilide (PS-LH₂) has been synthesized. The polystyrene anchored complexes have the formulae: PS-LM (where M = Cu, Zn, Cd, Ni, MoO₂, UO₂), PS-LFeCl.DMF, PS-LMn$.2$DMF and PS-LZr(OH)$_2.$DMF. The polystyrene-anchored coordination compounds have been characterized by elemental analysis, IR, reflectance, ESR and magnetic susceptibility measurements. The per cent reaction conversion of polystyrene anchored Schiff base to polystyrene supported coordination compounds lies between 28.98 and 85.9. The coordinated dimethylformamide is completely lost on heating the complexes. The shifts of the ν(C=N)(azomethine) and ν(C-O)(phenolic) stretches have been monitored in order to find out the donor sites of the ligands. The Cu(II) complex is paramagnetic with square planar structure; the Ni(II) complex is diamagnetic with square planar structure; the Zn(II) and Cd(II) complexes are diamagnetic and have tetrahedral structure; the Mn(II) and Fe(III) complexes are paramagnetic and have octahedral structure; the MoO₂(II) and UO₂(II) complexes are diamagnetic and have octahedral structure and the Zr(IV) complexes are diamagnetic and have pentagonal bipyramidal structure.

We describe here a simple modification of the HN(C)N experiment for the generation of serine/threonine check points in the three-dimensional experiment. The various `triplet of residue’ specific peak patterns in the spectra are documented for ease of analysis and sequential backbone resonance assignment. The performance of this experiment, referred to as HN(C)N-ST, is demonstrated using two proteins, one properly folded and the other completely denatured. It is noteworthy that, even in the denatured protein, where spectral dispersions are rather poor, about 90% of the sequential connectivities through the chain could be established from this single experiment. This would have great implications for structural genomics efforts.

The paper reports the synthesis and structural characterization of several organic-inorganic solids involving phosphomolybdate clusters. The Strandberg-type {P₂Mo$^{\text{VI}}_5$O₂₃} and the lower-valent {P₄Mo$^V_6$O₃₁} cluster based solids were isolated in the presence of $en$ (ethylenediamine) by controlling pH of the reaction medium. The lower-valent cluster invariably requires the presence of a suitable metal cation for further stabilization. A detailed investigation of the system was carried out where three different weak acids viz. oxalic acid, succinic acid and glycine were used in the entire pH range (1-12). Our results establish that the organic amine ($en$) is alone capable of reducing the molybdenum core in the absence of an organic acid at a suitable pH. Hence, pH of the reaction medium combined with suitable temperature favours the formation of lower-valent phosphomolybdate cluster. Higher pH favours the precipitation of a new sodium hydrogen phosphate.

An activity-guided fractionation was used to identify the antileishmanial compounds of Corymbia maculata. The hexane, ethyl acetate and methanol extracts were active in in vitro antileishmanial assay. Twelve polyphenols including 8-demethyl eucalyptin (1), eucalyptin (2), myrciaphenone A (3), myrciaphenone B (4), quercetin-3-𝑂-𝛽-D-xylopyranoside (5), myricetin-3-𝑂-𝛼-L-rhamnopyranoside (6), quercetin-3-𝑂-𝛽-D-galactopyranoside (7), quercetin-3-𝑂-𝛽-D-glucopyranoside (8), quercetin-3-𝑂-𝛼-L-rhamnopyranoside (9), syringic acid (10), gallic acid-3-methyl ether (11), gallic acid-4-methyl ether (12) and gallic acid (13) were isolated from the active extracts. All the tested compounds except 8-demethyleucalyptin and myrciaphenone B showed strong to moderate (6.9-24.5 𝜇M) antileishmanial activity against Leishmania donovani promastigotes. An HPLC-PDA method has been developed to detect/quantify 29 compounds in the extracts of C. maculata leaves. This validated method allows simultaneous quantitation of seven flavonoids, fourteen phloroglucinols and eight other polyphenols and can be applied for qualitative as well as quantitative determination of phytoconstituents in Eucalyptus matrices.

We present a Resolution of Identity and Cholesky Decomposition Based Implementation of EOMMP2 approximation. The RI and CD based EOM-MP2 shows significant speed-up and less storage requirement than the conventional canonical version and can be applied to very large systems. The newalgorithm used for this implementation eliminates the most storage requiring four-index quantities resulting in the decrease of storage requirement, reduction in I/O penalties and improved parallel performance, at the expense of more floating point operations. Therefore, the speed-up compared to conventional EOM-MP2 method is more prominent in case of EA, EE and SF case where the storage bottleneck is significant than the EOM-IP-MP2 method, where thestorage requirement is significantly less. However, the RI/CD based EOM-IP-MP2 can be coupled with frozen natural orbitals to gain further speed-up.

We propose a perturbative approximation to the vibrational coupled cluster method in bosonic representation to reduce the cost of calculating the cluster matrix elements by considering only the first order of S and r for the construction of the effective Hamiltonian e^se^-SHe^Se^s. With the systematic analysis of theresults of two molecules, H2O and 1,1-difluoroethylene, we find that the accuracy of the transition energies with such low order approximation is comparable to the fully converged VCCM

A theory for calculating vibrational energy levels and infrared intensities is developed in the equation of motion framework at the random phase approximation level. The vibrational Hamiltonian is expanded in the harmonic oscillator ladder operators making a Hamiltonian a bosonic Hamiltonian. Theexcitation operator is expanded to include at most two creations and two annihilation operators making it equivalent to the random phase approximation. The method is applied for the calculation of vibrational spectral properties of two molecules. The results are found to be satisfactory, making this approach a viable option for large molecular systems.