Search results for "Chalcogen"

Effect of Mn Doping on the Optical Properties of Chalcogenide Compounds ZnS and ZnTe

2020

In this paper, the influence of the addition of Mn on the optical properties of the binary compounds ZnS and ZnTe deposited by a close-spaced vacuum sublimation method onto nonoriented glass at different substrate temperatures was considered. The spectral dependences of the transmittance T (λ), reflectance R (λ) and the absorption α (λ), as well as the bandgap for each material (Eg) were measured and calculated.

Preparation and Characterization of Tungsten Chalcogenide Photocatalysts

1997

Tungsten chalcogenides powders have been prepared by sulfidation of WO3 with gaseous H2S. Different mixed WS2/WO3 systems have been obtained by varying the amount of initial WO3 powder, the time, o...

3.5-μm bandwidth mid-infrared supercontinuum generation in a 2-cm long suspended-core chalcogenide fiber

2014

A supercontinuum source extending from 0.6 to 4.1 µm has been successfully generated in a 2-cm long As2S3 chalcogenide suspended-core fiber by means of a nJ-level 200-fs pumping at 2.5 µm.

ChemInform Abstract: Preparation and Characterization of Tungsten Chalcogenide Photocatalysts.

2010

Tungsten chalcogenides powders have been prepared by sulfidation of WO3 with gaseous H2S. Different mixed WS2/WO3 systems have been obtained by varying the amount of initial WO3 powder, the time, o...

Large Magnetoresistance at Room Temperature in the Off-Stoichiometric Chalcogenide Cr0.92Te.

2006

Homoleptic Pnictogen-Chalcogen Coordination Complexes

2012

The synthesis and structural characterization of dicationic selenium and tellurium analogues of the carbodiphosphorane and triphosphenium families of compounds are reported. These complexes, [Ch(dppe)][OTf](2) [Ch = Se, Te; dppe = 1,2-bis(diphenylphosphino)ethane; OTf = trifluoromethanesulfonate], are formed using [Ch](2+) reagents via a ligand-exchange protocol and represent extremely rare examples of homoleptic pnictogen → chalcogen coordination complexes. The corresponding arsenic compounds were also prepared, [Ch(dpAse)][OTf](2) [Ch = Se, Te; dpAse = 1,2-bis(diphenylarsino)ethane], exhibiting the first instance of an arsenic → chalcogen dative bond. The electronic structures of these un…

Density functional/molecular dynamics simulations of phase-change materials

2013

Intramolecular 1,5-S...N σ-hole interaction in (E)-N′-(pyridin-4-ylmethylidene)thiophene-2-carbohydrazide

2020

The hydrazide-hydrazone forms inverse dimers via hydrogen bonding, but its conformation is defined by the presence of an intra­molecular chalcogen bond. Electrostatic forces dominate in the crystal packing and give rise to a layered supra­molecular structure.

Structural and Spectroscopic Studies of the PCP-Bridged Heavy Chalcogen-Centered Monoanions [HC(PPh2E)(PPh2)]− (E = Se, Te) and [HC(PR2E)2]− (E = Se,…

2009

Selenium- and tellurium-containing bis(diphenylphosphinoyl)methane monoanions were prepared by oxidation of the anion [HC(PPh2)2]− with elemental chalcogens. The selenium-containing isopropyl derivative was synthesized by generating [H2C(PiPr2)2] via a reaction between [H2C(PCl2)2] and 4 equiv of iPrMgCl prior to insitu oxidation with selenium followed by deprotonation with LiNiPr2. The solid-state structures of the lithium salts of the monochalcogeno anions TMEDA·Li[HC(PPh2E)(PPh2)] (E = Se (Li7a), E = Te (Li7b)) and the dichalcogeno anions TMEDA·Li[HC(PR2Se)2] (R = Ph (Li8a), iPr (Li8c)) revealed five- and six-membered LiEPCP and LiSePCPSe rings, respectively. The homoleptic group 12 comp…

Experimental and Theoretical Investigations of the Contact Ion Pairs Formed by Reactions of the Anions [(EPR2)2N]− (R = iPr, tBu; E = S, Se) with the…

2009

Reactions of the sodium salts [(EPR2)2N]Na(TMEDA) (R = iPr, tBu; E = S, Se) with the iodide salts [(TePR2)2N]I (R = iPr, tBu) in toluene produce the mixed-chalcogen systems [(EPR2)2N][(TePR2)2N] (6b, E = Se, R = tBu; 6c, E = S, R = tBu; 7b, E = Se, R = iPr; 7c, E = S, R = iPr). Compounds 6b, 6c, 7b, and 7c have been characterized in solution by variable-temperature multinuclear (31P, 77Se, and 125Te) NMR spectroscopy and in the solid state by single-crystal X-ray crystallography. The structures are comprised of contact ion pairs linked by bonds between Te and S or Se atoms. For the tert-butyl derivatives 6b and 6c, the anionic half of the molecule is coordinated in a bidentate (E,E′) fashio…