Melamine: A New Versatile Reagent for Inorganic Nanomaterials SynthesisYapryntsev A.D, Baranchikov A.E, Ivanov V.K*
Isomerism in Quantum Dots: Geometries, Band Gaps, Dipole Moments, Ionization Energies and Heats of Formation
Vitaly V. Chaban*
Quantum dot (QD) is a common term to designate a semiconductor nanostructure that confines motion of its conduction band electrons and/or valence band holes in all directions. QDs are so small particles that their electronic and optical properties differ drastically from the bulk volume of the corresponding substance. An entire QD can be seen as a single artificial atom because of its specific electronic structure (bound discrete electronic states).
M42 Primer Processing with Potassium and Copper Salt Formulations
M. M. Puszynski1*, N. Mehta, G. Cheng, K. D. Oyler, D. Fischer, T. M. Klapötke, and J. Stierstorfer
There has been a significant effort to develop suitable replacements for many energetic formulations containing environmentally undesirable compounds, especially lead. The purpose of this work was to synthesize and characterize tetraazido(1,2-di(1Htetrazol- 1-yl)ethane)dicopper(II) (Cu-salt) and dipotassium di-nitraminobistetrazole (K-salt) with the intent to replace lead styphnate in the M42 primer, while maintaining other compounds in the formulation. The formulations were prepared using a manual dry mixing procedure.
Polytypism of MoS2
We investigate the polytypism of MoS2 via first-principles crystal structure prediction approach. In particular, we combine the random searching method, AIRSS, for crystal structure prediction, and total energy calculations, based on density functional theory, by using CASTEP.
New Members of the Zig-Zag [MnIII4] Clusters from Polydentate Schiff Base Ligands
Catherine P. Raptopoulou*, Yiannis Sanakis, Vassilis Psycharis, Michael Pissas
New members of the family of zig-zag [MnIII4] clusters are reported. Compounds [MnIII 4(L1)2(HL1)2(H2O)2(MeOH)2](Br)2 (1) and [MnIII 4(L2)2(HL2)2(H2O)2(MeOH)2](Br)2 (2) were synthesized by the reaction of MnBr2∙4H2O with the Schiff base ligands OHC6H4-CH=NC(R)(CH2OH)2 (R = CH3, H3L1; R = C2H5, H3L2) in MeOH. The molecular structures of 1-2 consist of centrosymmetric tetranuclear cations and bromide anions.
L-Valine and Salicylaldehyde Derivative Schiff Base Zn(II) Complexes as UVA Sunscreen
Nanami Yoshida, Tomoka Shimada, Haruka Hiroki, Masahiro Takase, Takashiro Akitsu*
Ultraviolet (UV) of sunlight is classified into UVC, UVB and UVA according to wavelength. Sunscreen cosmetics must protect our skin against damage such as stains and freckles caused by UVB light or wrinkles caused by UVA light. Commonly sunscreen cosmetics are composed of inorganic UV-reflecting compounds and organic UV-absorbing ones. Although many good materials of both types of compounds for UVB protection are known, only a few UVA-absorbing organic compounds are known in spite of serious hazard of UVA light.
Recovery of Rhodium and Palladium from Spent Automotive Catalyst by a New Extractant
Asghar Karami*, Aminreza Ansari, Ehsan Ardestani Javadi, Nasrin Sakhaeian Haji Mohammadi, Ebrahim Bakhtiyaridoost
This work examines a hydrometallurgical route for processing spent commercial catalysts containing Rh-Pd supported on a substrate of metals such as Al/Mg/ Ce used in Iranian car for recovery of the noble metal with less final wastes generation. Samples were initially pre-oxidized (650°C, 2 h, 1atm) in order to eliminate coke and the other pollutants. The basis of the present route is the partial dissolution of the pre-oxidized catalyst in a non aqua-regia medium.
Synthesis and Characterization of 5-methyl-2,4,6-trinitrobenzene-1,3-diolate and its Energetic Cesium Salt
Andreas Drechsel, Thomas M. Klapötke*, Tomasz G. Witkowski
The synthesis and characterization of the primary explosive cesium 5-methyl-2,4,6-trinitrobenzene-1,3-diolate (3) as well as its precursor compounds is described. The compounds were isolated as pure substances and characterized using multinuclear (1H, 13C) NMR spectroscopy, vibrational (IR and Raman) spectroscopy, mass spectrometry and elemental analysis. The thermal behavior of the compounds was established using differential scanning calorimetry. The solid state structure of 5-methyl- 2,4,6-trinitrobenzene-1,3-diol (2) was determined using low temperature single crystal X-ray diffraction. The friction and impact sensitivity tests were carried out using the BAM friction tester and BAM drophammer respectively.
Eu(Ш)-based Coordination Polymers: Ligand-Dependent Morphology and Photoluminescence Properties
Min Shuai, Mengmeng Shi, Hualan Xu, Shengliang Zhong*, Chenghui Zeng*
A facile template-free solvothermal strategy has been developed to synthesize Eu(III)-based coordination polymer (CP) hollow spheres, using N, N-dimethylformamide (DMF) as a solvent and 2-aminoterephthalic acid (H2ATPA) as a ligand. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), elemental analyses (EA), Fourier transform infrared (FT-IR), Brunauer− Emmett−Teller (BET), and thermogravimetric analysis (TGA). SEM and TEM results show that the Eu-ATPA hollow microspheres have diameters of 200–400 nm and a thickness of about 15–30 nm.
Chromium tricarbonyl η6-Complexes of (R)-helicene -A DFT Study
Isomeric chromium tricarbonyl η6-complexes of (R)-helicene have been considered theoretically at the level of DFT ( as B3LYP/ 6-31G(d,p), B3LYP/LANL2DZ, B3LYP/SBKJC and B3LYP/6-31G(d,p)// B3LYP/SBKJC) in order to investigate some molecular orbital, electronic and thermodynamic properties. The chromium tricarbonyl η6-complex is formed each time on different ring of (R)-helicene molecule ( on the same side of the molecular surface) to get the isomeric complexes and the effect of complexation on the stability and aromaticity of (R)-helicene has been investigated by means of energy and NICS calculations results.