Mix sulfur

Quite a number of mixed sulfur-nitrogen macrocycles have been prepared, but these have largely been by the methods outlined in Chaps. 4 and 5 for the respective heteroatoms. An alternative method, involves the formation of a Schiff base, followed by reduction to the fully saturated system, if desired. An interesting example of the Schiff base formation is found in the reaction formulated in (6.12). Dialdehyde 14 is added to ethylenediamine in a solution containing ferrous ions. Although fully characterized, the yield for the reaction is not recorded. To avoid confusion with the original literature, we note the claim that the dialdehyde [14] was readily prepared in good yield by reaction of the disodium salt of 3-thiapentane-l, 5-diol . The latter must be the dithiol rather than the diol. 

Rhenium(VI) complexes, 4,194 alkoxides, 4,196 amides, 4,194 amines, 4,199 carboxylates, 4,199 dimethylformamide, 4,199 dioxane, 4,198 halides, 4,195,199 2-hydroxypyridine, 4,199 imides, 4,194 magnetic behavior, 1,271 mixed sulfur-nitrogen compounds, 4,196 N heterocycles, 4,199 nitrides, 4,194 oxide halides, 4, 195 oxoanions,4,196 pyridine, 4,199 sulfates, 4,198 sulfur compounds, 4,196 tellurates, 4,198... 

The mixed sulfuric phosphoric anhydride (PAdoPS or PAPS) of 3 -phospho-5 -adenylic acid is named as an acyl sulfate ... 

Entry 5 is an example of nitration in acetic anhydride. An interesting aspect of this reaction is its high selectivity for the ortho position. Entry 6 is an example of the use of trifluoroacetic anhydride. Entry 7 illustrates the use of a zeolite catalyst with improved para selectivity. With mixed sulfuric and nitric acids, this reaction gives a 1.8 1 para ortho ratio. Entry 8 involves nitration using a lanthanide catalyst, whereas Entry 9 illustrates catalysis by Sc(03SCF3)3. Entry 10 shows nitration done directly with N02+BF4, and Entry 11 is also a transfer nitration. Entry 12 is an example of the use of the N02—03 nitration method. 

Making Predictions Predict the result of mixing sulfuric acid and potassium hydroxide solutions. 

In summary, the fragmentary evidence at hand suggests that sulfur was the primordial iron complexing material and that this ligand system was selectively modified by stepwise transition to a mixed sulfur-nitrogen and sulfur-oxygen and, finally, to an all-oxygen type of coordination. 

If you mix sulfur and iron filings in a certain proportion and then heat the mixture, you can see a red glow spread through the mixture. After it cools, the black solid lump which has been produced, even if crushed into a powder, does not dissolve in carbon disulfide and is not attracted by a magnet. The material has a new set of properties it is a compound, called iron(II) sulfide. It has a definite composition, and if, for example, you had mixed more iron with the sulfur originally, some iron(II) sulfide and some leftover iron would have resulted. The extra iron would not have become part of the compound. 

Raman spectroscopy is a useful probe for detecting transannular S - S interactions in bicyclic or cage S-N molecules or ions. The strongly Raman active vibrations occur at frequencies in the range 180-300 cm-1, and for S- -S distances in the range 2.4-2.7 A. On the basis of symmetry considerations, the Raman spectrum of the mixed sulfur-selenium nitride S2Se2N4 was assigned to the 1,5- rather than the 1,3- isomer.37... 

Mixed chalcogen derivatives of phosphinic and phosphoric acids are also known, the most studied being the mixed sulfur-oxygen species. Thiophos-phoric acids exist in two different isomeric forms - the thiono form (18a) and the thiolo form (18b). The equilibria usually sits somewhere in between these two species, being dependent upon the nature of the R substituents, the solvent and in some cases the concentration. Thiophosphinic acids are also able to interconvert between the thiono (19a) and thiolo (19b) tautomers, although the equilibrium position usually sits well on the side of the thiono tautomer.1... 

Recently, the first structural characterization of mixed sulfur selenium dihalides, SeSX2 (X = Br, Cl), has been reported in mixtures of S2C12 and Se2X2 (X = Br, Cl).29,30 In addition, two-dimensional NMR exchange... 

The isolation of pure compounds from mixed sulfur-selenium melts was further questioned by mass spectroscopic studies The existence of SeS., Se Sg,... 

It has been shown recently that at 20 °C the unstable iodosulfanes (n = 1,2,...) decompose to give homocyclic sulfur molecules and iodine In a similar fashion SCjIj prepared from Se Clj and solid KI in carbon disulfide solution produces Seg and polymeric selenium Mixed sulfur-selenium ring molecules can be prepared by the reaction of mixtures of Se2Cl2 and chlorosulfanes (S Cl2 n = 1, 2, 4, 6-8) with potassium iodide in carbon disulfide solution. The subsequent decomposition of the unstable iodides results in the formation of mixed SeoS8 molecules. The general reaction scheme can be presented as follows ... 

Fluoro-2,4 dinitropbenol, yel ctysts (from petr eth), mp 138—39°. Prepd by stepwise nitration of m-fluorophenol (Refs 1 6) 5 FluorO 2,4-dinitTophenol, lt-yel microcrysts (from petr eth), mp 138—39° v sol in w prepd by nitrating 3 fluorophenol with mixed sulfuric-nitric acid at 10—15° and hydrolizing the reaction prodict with steam (Refs 1 6) P-Fluoro A-dinitropbenoU yel crysts (from aq ale or benzine), mp 102° v sol in benz, MeOH St ale mod sol in w obtd with other products by nitrating 2-fluoroanisole or 2-fluorophenetol with mixed acid at —5 to 0°... 

Transport of the mixed sulfur concrete was accomplished by motorized wheelbarrows with insulated buckets (figure 5). Covers would have assisted in retaining the heat of the mix, but were not necessary in the summer months in south Texas. 

Sulfur concretes (SC) are basically simple materials, made by mixing sulfur plus certain additives with heated mineral aggregates. On cooling, SC sets to give a high-strength material with superb corrosion resistance. 

To prepare the SC mix, sulfur was heated in a one-bag capacity concrete mixer fitted with two 3,000 BTU propane burners. 

Nitro-/>-cymene has always been secured by the nitration of the hydrocarbon, either by the use of mixed sulfuric and nitric acids with2 or without3 the addition of acetic acid, or by fuming nitric acid in acetic acid.4... 

Sa I (solid). According to Ogier7 there is no heat effect on mixing sulfur and iodine. 

Sulfuric acid (oil of vitriol, H2S04) is a colorless, oily liquid, dense, highly reactive, and miscible with water in all proportions. Heat is evolved when concentrated sulfuric acid is mixed with water and, as a safety precaution, the acid should be poured into the water rather than water poured into the acid. Anhydrous, 100% sulfuric acid, is a colorless, odorless, heavy, oily liquid (boiling point 338°C with decomposition to 98.3% sulfuric acid and sulfur trioxide). Oleum is excess sulfur trioxide dissolved in sulfuric acid. For example, 20% oleum is a 20% sulfur trioxide-80% sulfuric acid mix. Sulfuric acid will dissolve most metals and the concentrated acid oxidizes, dehydrates, or sulfonates most organic compounds, sometimes causing charring. 

Tetryl [2,4,6-trinitrophenylmethylnitramine, C6H2(N02)3NCH3N02] is manufactured by the action of mixed sulfuric and nitric acid on dimethyl-aniline in a multiple-stage nitration. 

The synthesis of the mixed sulfur-selenium donor BEDS-TTF (BEST) via the tetralithiation of TTF was mentioned above [53]. Bis(ethylenedithio) tetraselenafulvalene (BEDT-TSF, BETS) is obtained in good yield following the sequence outlined in Scheme 14. The synthesis makes use of a titanium-cyclopentadiene complex to stabilize a problematic, unstable synthetic intermediate (35) [7]. 

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