Variation in viscosity and ion conductivity of a polymer-salt complex exposed to gamma irradiation

We study changes in microstructure and resulting changes in the properties of PEO(1 − x)-NH₄ClO₄(x) samples where x = 0.18, when irradiated with gamma doses varying up to 50 kGy. Viscosities of aqueous solutions of the irradiated samples give an idea of the change in molecular weight and show correlation with ion conductivity. On the whole, there is a chain scission on irradiation, though there is evidence of some cross-linking at higher doses. The ion conductivity shows a strong increase for an irradiation of 35 kGy. DSC studies indicate a decrease in crystallinity with gamma dose.     

On the conversion XCN ⟷ XNC via an efficient and economic perturbative wave function approach

The energetics, structures, reaction paths and mechanisms for the conversion XCN ? XNC, with X = H, Li, CH₃ and H₂B have been investigated through the use of improved virtual orbitals (IVO) in a second-order multireference perturbation theory (MRPT) treatment within the framework of state-specific (SS) parametrisation of the wave function for the target state (IVO-SSMRPT). Due to its flexibility, IVO-SSMRPT formulation allows us to take into account the major part of the coupling between the dynamic and nondynamic correlation effects in an accurate manner. The results obtained by our calculations agree well with the state-of-the-art electronic structure methods and reference values which illustrates that IVO-SSMRPT, when applied judiciously, can be very accurate for reaction surfaces of XCN ? XNC isomerisation, barrier and bond-parameters.     

Characterization and growth of CdS nanoparticles by a cost effective chemical reduction method

A simple chemical reduction method is followed to grow CdS nanoparticles at room temperature with different duration of time. The grown samples are ultrasonicated in ethanol. The dispersed samples are characterized using electron diffraction techniques. Simultaneously optical absorption, photoluminescence and longtime photorelaxation of these samples are studied at room temperature. An increase in band gap is observed in each case as compared to bulk CdS. Also particle size increases with increase of growth time and hence there is decrease of band gap with increase of growth duration. Simultaneously long time relaxation increases with increase of growth time. An attempt is made to correlate the structural, optical, electrical and opto‐electrical properties. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Pd-Catalyzed Regioselective Domino C−C Bond Formation to Access N-Fused Benzimidazo-Indolo-Isoquinoline Heterocycles

Regioselective synthesis of N-fused benzimidazo-indolo-isoquinoline heterocycles via Pd-catalyzed domino coupling reaction of 1-(1-methyl-1H-indol-2-yl)-1H-benzimidazoles and aryl halides was developed. This one pot methodology proceeded via a five-member carbopalladacycle intermediate and provided direct and facile route to access structurally complex polyheterocycles in moderate to good yields. These unique hybrid molecules resembled structural similarity with naturally isolated alkaloids. Notably, the present domino process occurred through activation of three C−H bonds and the simultaneous formation of two new C−C bonds in one-shot. These molecules exhibited strong solid and solution phase fluorescence and their emission spectra in both the medium are reported here.