S4N4 Tetrasulfur tetranitride

Because nitrogen compounds of Se and Te are much less important than those of sulfur, this section will be devoted to the sulfur compounds. The binary compounds containing sulfur and nitrogen have several unusual structures and properties that make them an interesting series. Probably the most studied compound of this type is S4N4, tetrasulfur tetranitride, which is prepared by the following reactions ... 

S4N2 Tetrasulfur dinitride, 6 128 S4N4 Tetrasulfur tetranitride, 6 124... 

Tetrasulfur tetranitride, S4N4 has a structure that can be considered as a hybrid of the following two resonance structures ... 

Tetrasulfur tetranitride (9a) adopts a cage structure with equal S-N bond lengths (1.62 A) and two weak transannular S- -S interactions of ca. 2.60 A at room temperature. Tetraselenium tetranitride and the hybrid l,5-Se2S2N4 also have similar structures (9b, 10).54 Rietveld analysis indicates that S4N4 undergoes a transition to a new orthorhombic phase at 397 K.55... 

Reactions of arylchloromethyl-p-tolyl sulfoxides with tetrasulfur tetranitride (S4N4) yield 3,5-diaryl-1,2,4,6-thiatriazine 1-oxides <00T7153>. [4+2] Cycloadditions of thiazyl... 

The reactions of l-aryl-2,2,2-trifluoroethanone oximes 378 with tetrasulfur tetranitride (S4N4) in toluene at reflux gave 5-aryl-5-trifluoromethyl-4//-l,3,2,4,6-dithiatriazines 379, l-aryl-2,2,2-trifluoroethylideneaminosulfenamides 380 and sulfur (equation 165) . ... 

We demonstrate the use of local coordinate systems with the molecule of tetrasulfur tetranitride, S4N4, (Fig. 4.2) as an example. It occupies a general position in its crystal s space group, with one molecule in the asymmetric unit. Thus, there are eight crystallographically independent atoms. If multipoles up to and including the hexadecapoles are included, the number of population parameters... 

Tetrasulfur tetranitride (S4N4) is perhaps the most widely reported reagent for the [3 -f 2] (type A or B) formation of the 1,2,5-thiadiazole ring (Table 5) <90MI 409-01>. 

A series of 3-acyl and 3-aroyl-4-substituted 1,2,5-thiadiazoles 82 have been synthesised by reaction of 3,S-disubstituted isoxazoles 81 with tetrasulfur tetranitride antimony pentachloride (S4N4.SbCl5) in toluene at 90 C to reflux temperature. Compounds 82 are produced regioselectively and a plausible mechanism for their formation discussed. Under the same conditions, 3,4-dialkyl and 5-alkyl(aryl)-isoxazoles furnished chloroketones of type 83 <98JCS(P1)2175>. 

Early reports on tetrasulfur tetranitride (S4N4 = L) suggest the formation of [VC14L]... 

CAUTIONARY NOTE CONCERNING THE STORING AND HANDLING OF TETRASULFUR TETRANITRIDE, S4N4... 

Tetrasulfur tetranitride can be prepared in good yield by the method described by Becke-Goehring. In this revision of the method those points are emphasized which, if neglected, can cause difficulty. Because S4N4 is explosive, and because the large amounts of material involved in the earlier method are unwieldy, the synthesis has been scaled... 

Tetrasulfur tetranitride, as prepared by the above procedures, usually has a melting point of 178 to 179°. However, by repeated recrystallization from benzene or by purification on an alumina chromatographic column, S4N4 with a melting point as high as 187 to 187.5° has been obtained. It has been observed that the sensitivity of S4N4 toward both shock and temperature increases with its purity. Even the... 

Diazoalkanes react with tetrasulfur tetranitride to give red crystalline l,3/l 5, 5,2,4-trithiadiazines (85), a new ring system with an almost planar ring. Thus, addition of ethereal diazomethane to S4N4 in dichloromethane at room temperature affords, after 0.5 h, the 1,3,5,2,4-trithiadiazine in 37% yield. Similar reaction of S4N4 with aryldiazomethanes gives open chain compounds as major... 

Tetrasulfur tetranitride,11 S4N4, is purified by recrystallization from chloroform, is pumped for several hours on the high-vacuum system and is finally sublimed under vacuum at 80-90° before use.16 The purity of the compound is checked by its melting point (found, 185.5-186° literature values 178-1870).9,10... 

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