an azobenzene bridge was introduced into the lower (or smaller) rim of p-tert-butylcalix[8]arene to form 1,5-singly bridged calix[8]arene derivatives, respectively. bridged calix[8]arene of conformationally rigid wereisolated. the stability of the two structures of bridged calix[8]arenes have been compared.the study of organicstructure to form nanoporous structures is a well known in chemistry ...

A new proton transfer compound, formulated as (Hamp-6-pic)(Hpyzd) ∙H2O (1), has been synthesized from the reaction of pyrazine-2,3-dicarboxylic acid (H2pyzd)  and 2-amino-6-methyl pyridine (amp-6-pic), in 1:1 molar ratio. Extensive O−H×××O, N−H×××N and O−H×××O hydrogen bonds involving (Hamp-6-pic)+ cation, (Hpyzd)- anion and co-crystal water molecule٫ static electronic٫ and π…π stacking interac...

In this work, the investigation of wave absorption, phase formation, crystal structure and magnetic properties of SrFe12O19 hexa-ferrites nanoparticles that synthesized by co-precipitation using a microwave heating system and polyaniline-SrFe12O19 was carried out by using a combination of vector network analyser (VNA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier tra...

The structure of N,N'-bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine, C19H22N2O2, has been studied at low temperature (120K) by means of single-crystal X-ray diffraction. Solving the structure shows an orthorhombic unit cell, with P212121 space group, Z = 4, a = 6.1046 (4) Å, b = 15.8349 (11)</e...

We have constructed polymer-stabilized nematic liquid crystals by photopolymerizing diacrylate monomers in the nematic phase. The orientation of the liquid crystal was controlled by the polymer network. We studied the Freedericksz transition in these systems. Experimentally we studied the transition by measuring the capacitance of the liquid crystal cells as a function of applied voltage. The t...

normal 0 false false false en-us x-none ar-sa dear editor i read with interest the study conducted by karrari and colleagues regarding “iranian crystal a misunderstanding of the crystal-meth” published in your journal. [ 1 ] in this study, the authors have explained that the pattern of substances of abuse is varied in different parts of the world , also in iran, and the main ingredient of stree...

In this paper, conventional SAPO-34 and Cerium Hierarchical SAPO-34 zeolites are synthesized using a hydrothermal method for methanol-to-propylene (MTP) reaction. The Ce-H-SAPO-34 catalyst shows a slightly larger crystal size, bimodal pore size distribution (microporous and mesoporous) and lower surface acidity compared to conventional SAPO-34 catalysts. According to these physicochemical prope...