nanocrystalline sio2–hclo4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. the procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. in practice, this method is a combination of a satisfac...

in this report, synthesis, characterization and application of silica perchloric acid nanosphere as a novel and heterogeneous catalyst is described. these nanospheres have been characterized by xrd, ft-ir, bet and tga spectra and also by sem and tem images. the results show that it has a spherical shape and the particles size are between 75 and 100 nm. the catalytic activity has been investigat...

Nanocrystalline SiO2–HClO4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. The procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. In practice, this method is a combination of a satisfac...

A novel europium ligand 2,2',2'',2'''-(4,7-diphenyl-1,10-phenanthroline-2,9-diyl) bis (methylene) bis (azanetriyl) tetra acetic acid (BC-EDTA) was synthesized and characterized. It shows an emission spectrum peak at 610 nm when it is excited at 360 nm, with a large Stock shift (250 nm). It is covalently coated on the surface of a bare silica nanosphere containi free amino groups, using 1-ethyl-...

Monodisperse single-crystalline α-cristobalite nanospheres have been synthesized by hydrocarbon-pyrolysis-induced carbon deposition on amorphous silica aerosol nanoparticles, devitrification of the coated silica at high temperature, and subsequent carbon removal by oxidation. The nanosphere size can be well controlled by tuning the size of the colloidal silica precursor. Uniform, high-purity na...

An efficient synthetic route to prepare O -(2- -benzyl-3,4-di- -acetyl-?/?- l -fucopyranosyl)-trichloroacetimidate from -fucose was developed by introducing the thiophenyl group at anomeric center and benzylidene functional protect 3 4 positions. Although three approaches were considered, best result obtained when, after 2-hydroxyl benzylation, both protective groups simultaneously removed usin...

Perchloric acid adsorbed on silica gel efficiently catalyses acetylation of structurally diverse phenols, alcohols, thiols, and amines under solvent free conditions.

Subwavelength nanostructures are considered as promising building blocks for antireflection and light trapping applications. In this study, we demonstrate excellent broadband antireflection effect from thin films of monolayer silica nanospheres with a diameter of 100 nm prepared by Langmuir-Blodgett method on glass substrates. With a single layer of compact silica nanosphere thin film coated on...

We study the optical properties of the nanosphere-in-a-nanoegg structure (NSNE) by the three-dimensional finite difference time domain method. We demonstrate the suppression of the high-order plasmon modes in NSNE, which is induced by the plasmon interaction between the inner nanosphere and the outer nanoegg shell. A two-layer plasmon hybridization model is presented to explain this mechanism. ...