One Sulfur Atom

Thiiranes in the synthesis of thiocarbonyl-S-sulfides 89PS(43)63. Thiiranium ions as intermediates 88MI15 90MI11. 

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In general, collectors for the flotation separation of sulfides and precious metals contain at least one sulfur atom ia an appropriate bonding state. 

The thiosulfate ion, 820 is a stmctural analogue of the sulfate ion where one oxygen atom is replaced by one sulfur atom. The two sulfur atoms of thiosulfate thus are not equivalent. Indeed, the unique chemistry of the thiosulfate ion is dominated by the sulfide-like sulfur atom which is responsible for both the reducing properties and complexing abiUties. The abiUty of thiosulfates to dissolve silver haUdes through complex formation is the basis for their commercial appHcation in photography (qv). 

Three-membered rings containing one sulfur atom are named as thiiranes (1) or thiirenes... 

Mass spectrometry played an important role in the recent characterization of small cyclic sulfur imides that are formally derived from the unstable cyclic sulfur allotropes Se and S7 by the replacement of one sulfur atom by an NR group. The compounds SsNOct and SeNOct (Section 6.2.2), which are yellow oils, exhibit molecular ions of medium intensity in their mass spectra. ... 

Two Nitrogen Atoms and One Sulfur Atom. s -Triazolo[3,4-d]-l,3,4-thiadiazole derivatives 98Ft(48)561. 

Sulfur Compounds. All crude oils contain sulfur in one of several forms including elemental sulfur, hydrogen sulfide, carbonyl sulfide (COS), and in aliphatic and aromatic compounds. The amount of sulfur-containing compounds increases progressively with an increase in the boiling point of the fraction. A majority of these compounds have one sulfur atom per molecule, but certain aromatic and polynuclear aromatic molecules found in low concentrations in crude oil contain two and even three sulfur atoms. Identification of the individual sulfur compounds in the heavy fractions poses a considerable challenge to the analytical chemist. 

According to the Hantzsch-Widman system, the seven-membered unsaturated hcterocyclc with one sulfur atom is named thiepin (1). The three different benzothiepins are assigned by the position of sulfur 1-benzothiepin (2), 2-benzothiepin (3) and 3-benzothiepin (4). Of the four possible dibenzothiepins only dibenzo[6,r/]thiepin (5) and dibenzo[A,/]thiepin (6) are of importance for synthesis, while the other two isomers, which contain unfavorable o-quinoid structures, exist mainly as the stable dihydro compounds, i.c. 5,7-dihydrodibenzo[c,t ]thiepin (7) and 6,1 l-dihydrodibenzo[6,c ]thiepin (8). Benzannulation over all double bonds results in tri-benzo[6,(7,/]thiepin (9). 

Name the following (a) a compound with three oxygen atoms and one bromine atom per molecule (b) a compound with one iodine atom and three chlorine atoms per molecule and (c) a compound with one sulfur atom and four iodine atoms per molecule. 

The more electronegative element will take the negative oxidation state, (a) The maximum oxidation state of sulfur is +6 the most common negative oxidation number of oxygen is -2. Therefore, it takes three oxygen atoms to balance one sulfur atom, and the formula is SO v (b) The maximum oxidation state of carbon is +4 the only oxidation number of fluorine in its compounds is - 1. Therefore, it takes four fluorine atoms to balance one carbon atom, and the formula is CF4,... 

Potassium is in group IA and sulfur is in group VIA, and so each potassium atom has one outermost electron and each sulfur atom has six. Therefore, it takes two potassium atoms to supply the two electrons needed by one sulfur atom. 

The S-N unit is the thiazyl group and S4N3+ contains three of these units plus one sulfur atom (designated as thio) hence the name. When S4N4 reacts with NOC1, a five-membered ring is produced. 

Isolable dithiiranes66 70 are rather stable under neutral or acidic conditions, they lose one sulfur atom by treatment with bases to yield thioketones. On heating they isomerize to 6-oxa-7,8-dithiabicyclo[3.2.1.] octanes via thiosulhne or decompose to thioketones. 

HETEROCYCLES CONTAINING ONE SULFUR ATOM 6.4.2.1 Thiopyrans and analogues... 

The site responsible for CH30 formation can be identified with the use of CO as a probe molecule. As increasing amounts of sulfur are added to Ni(100), the desorption state characteristic of CO on the clean surface disappears, and two new states appear at 315 and 380 K, respectively. These states persist from about 0g - 0.15 to 0gO. 46 (see Figure 5). In this coverage range one sulfur atom blocks adsorption of one CO molecule (15). 

An example of the formation of a cyclic product, containing only one sulfur atom, is the reaction of Sx anions with activated double bonds of 1,5 -diphenyl-1,4-pentadiene-3-one yielding in a substituted oxotetrahydrothiopy-ran (Scheme 62) [253]. 

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