Silica sulfuric acid (SSA) mediated synthesis of naphtho[2,1‐b]furan derivatives starting from β‐nitrostyrene derivatives and β‐naphthol derivatives under solvent‐free conditions have been developed. The scope of SSA as a heterogeneous catalyst is extended to one‐pot multicomponent reaction for the synthesis of functionalized pyrazole derivatives under solvent‐free conditions from readily available β‐nitrostyrene derivatives, acetyl acetone, and hydrazine hydrate. The synthetic methods have significant advantages such as solvent‐free conditions, simple operation, shorter reaction times, ease and clean isolation procedures, and very good yields of products.

Metal-free regioselective strategy for the synthesis of 2-nitro-3-arylimidazo[1,2-a]pyridines from β-nitrostyrene and 2-aminopyridines under aerobic conditions using silica sulfuric acid (SSA) as heterogeneous catalyst has been developed. The synthetic methodology provides the title compounds with good yields under mild conditions, and complete regioselectivity is observed.

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We report the structure and dielectric properties of Fe0.7Cr1.3O3 nanocrystallites synthesized by co-precipitation method. X-ray diffraction shows that the nanoparticles possess a typical corundum structure and no other impurity phases are observed. These nanoparticles exhibit a high dielectric permittivity (' ~ 103) at room temperature below 1 kHz. The dielectric relaxation follows the thermally activated process with activation energy of 0.226 eV. Both components of grain relaxation and grain boundary relaxation times were extracted from modulus spectra. The internal barrier layer capacitance (IBLC) effect is responsible for observed high dielectric response in these nanoparticles.

We are reporting the synthesis along with magnetic, ac conductivity and dielectric properties of hematite nanocrystallites. The prepared Fe2O3 is crystallizing in corundum structure which belongs to the rhombohedron system with the space group R3-c. The magnetization data shows a typical Morin transition, TN = 265 K for 110 nm crystallites, whereas this transition is decreasing with decrease in crystallite size, TN = 252 K for 33 nm. The value of magnetization is increased with increasing crystallite size. The enhanced dielectric permittivity and ac conductivity were observed in higher hematite crystallite size. The overall dielectric response has revealed conduction mechanism is due to the extrinsic contribution from the dominant Maxwell-Wagner polarization.