Sodium chalcogenides

In the particular case of bis(dichloroorganostannyl)methane structures, obtained from the gem-distannyl compounds shown in reaction 13, treatment with sodium chalcogenides... 

In addition to oxides, a number of other compositions may be synthesized. In general, any stoichiometry is fair game through the same reactions that one does in bulk scale. For example, sulfides through reaction of precursors with H2S, nitrides through NH3 exposure, Reactions with sodium chalcogenides... 

Lavela P, Comad M, Mrotzek A, Harbrecht B, Tirado JL (1999) Electrochemical lithium and sodium intercalation into the tantalum-rich layered chalcogenides Ta2Se and Ta2Te3. J AUoy Compd 282 93-100... 

Vlasov YG, Bychkov EA (1989) Sodium ion-selective chalcogenide glass electrodes. Anal Lett 22 1125-1144... 

Although direct synthesis of cadmium chalcogenide quantum dots in the aqueous phase was achieved nearly 30 years ago, the synthesis of size-controlled CdSe quantum dots in the aqueous phase became possible only recently. Rogach et al. successfully synthesized CdSe quantum dots in the aqueous phase from a mixture of cadmium perchlorate (4.7 mmol), sodium hydroselenide (2.2 mmol), and 2-mercaptoethanol or 1-thioglycerol (11.54mmol) [15]. In a typical synthesis, the above mixture was refluxed in an aqueous NaOH solution (pH = 11.2) in a N2... 

The first deposition experiments using SILAR were performed to grow zinc and cadmium chalcogenide films.1 Metal salt solutions and sodium sulfide were used as precursors in most experiments. Table 8.2 provides a more complete... 

Zinc chalcogenide thin hlms have been grown by ECALE using zinc sulphate as metal source and sodium sulphide and sodium selenite as chalcogenide precursors.145-148 The formation of the hrst layers of ZnS on (lll)Au has been analyzed by STM and XPS.145 HRSEM images showed that the him surface was very hat, even at an atomic level. On the other hand, thicker ZnS hlms were formed of well-separated crystal nuclei. The stoichiometry of a thicker ZnS him showed a slight excess of sulphur, with a Zn S ratio of 1 1.2. The band gap of a thicker him (deposition time 12 h) was 3.60eV.147... 

Cadmium chalcogenide thin hlms have been grown by ECALE using cadmium sulphate as metal source and sodium sulphide, sodium selenite,... 

Bismuth nitrate together with sodium sulphide and tellurium oxide have been used to grow bismuth chalcogenide films.162-166 The stoichiometric ratio 2 3 has been confirmed by XPS, EDX, and XRD.162-166 The Bi2Te3 films were rough and consisted of particles with a diameter of 30-100nm, and electron probe microanalysis showed a worm-like network structure.164-166... 

Metal oxides and chalcogenides MRH Chromium trioxide 7.20/83, sodium peroxide... 

The chalcogenide 97, 107/,127/-dibenzo[c/][l,5]selenathiocin, has been synthesized by the reaction between bis(2-bromomethylphenyl)sulfide 134 and sodium selenide in a mixture of THF and ethanol at 0°C for 17 h in rather poor yield (25%) <1998T11813>. A new phosphorus-selenium eight-membered heterocycle 136 has been synthesized from the bis-bromide 135 by treatment with sodium selenide in ethanol at room temperature in 81% yield (Scheme 13) <1995H(41)2647>. 

In most cases, the iodide-triiodide redox couple has been employed (presumably because of its success in shuttling the photo-oxidized dye in the sensitization experiments) although other redox electrolytes e.g., SCN /(SCN)2 , [342] have also been employed. For the chalcogenide films, sodium selenosulfite was employed [319]. It must be noted that, aside from losses due to the surface recombination and back-reactions, an additional loss component from the increase in film resistance must also be recognized especially as the film thickness is increased. The resistance loss manifests as a deterioration in the photovoltage and fill factor. 

Selenium can be oxidized by lithiumtriethylborohydride in THF to provide high yields of the respective chalcogenide derivatives, which can then be used in situ for further reactions. The presence of a small amount of tBuOH apparently acts to increase the yield of product through an unknown mechanism. Sodium diselenide can be prepared by a related reaction between sodium borohydride (79 mmol) and selenium (38 mmol) in water. After the initial reaction subsides, additional selenium (38 mmol) is added and the mixture heated briefly ". ... 

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