Sulphur-Nitrogen Compounds

Sulphur-Nitrogen Compounds.— The chemistry of sulphur-nitrogen compounds has been reviewed. In particular, the newer aspects of these compounds were related to a background of earlier work and attention was drawn to structural similarities between certain recently discovered compounds and elemental sulphur. The topics covered include S4N4 and its reactions with Lewis acids, thionitrosyl derivatives, imide derivatives, and anionic and cationic species. 

Linear Compounds. An electron-diffraction study of gaseous thiazyl chloride has shown the molecule to have the arrangement NSQ rather than SNCl. This result is in agreement with recent microwave studies on the 

The crystal and molecular structure of 1,5-bis-(p-chlorophenyl)-2,4-diaza-1,3,5-trithiapenta-2,3-diene, obtained from the reaction of / -chlorophenyl-magnesium bromide with S4N4, has been determined. The crystals are monoclinic, of space group P2j/c,Z =4,a = 3.972,6 = 19.531, c = 19.37 A, P = 109.7°. The nearly planar structure of the molecule (21) is of the linear 

Bis(trifluoromethyIsulphenyl)amine, (F3CS)aNH, is a very weak acid and interacts with trimethylamine (and pyridine) to form 1 1 adducts  

King Compounds. The reaction of S4N4 with two moles of (MesSn)3N has been shown to yield 5,5-dimethyl-l,3A, 2,4,5-dithiadiazastannole (28), sulphur JVJV -bis(trimethylstannyl)di-imide (29), and tetramethylstannane. According to i.r. investigations, the first reaction products are only (29) and sulphur. Me4Sn and (28) are formed on vacuum-sublimation of the primary 

Sulphur-Nitrogen Compounds.—Linear Compounds. Results from ab initio Hartree-Fock calculations on the ground states of NSF and SSO have been reported.87 The photoelectron spectra of the bent, triatomic molecules NSF, SSO, 03, S02, and NSC1 were compared and experimental details of the photoelectron spectrum of SSO presented. Pyrolysis of the tetrathiatriazyl halide S4N3X at low pressures gives the corresponding thiazyl halide XSN where X = C1 or Br but not where X = I 88 

Infrared spectra of both C1SN and BrSN suspended in argon matrices have verified the molecular identities, and indicate, through normal-co-ordinate analysis, that both molecules are bent, with C1SN=117° and BrSN = 118° 

Rosmus, P. D. Dacre, B. Solouki, and H. Bock, Theor. Chim. Acta, 1974, 35, 129. 

Elements of Group VI the isomerization appears to be the greater energy of the C—N bond which is formed compared to that of the C—S bond which is broken. It is certainly not due to increased strength of the N—S multiple bond, which appears to be weaker in the product. No attempt was made to elucidate the mechanism of the isomerization reaction however, a reasonable possibility is thought to be a two-centred bimolecular reaction involving an intermediate with a six-membered ring (11). 

Addition of SF4 to the CN triple bond of the difluoronitridosulphur amides N=SF2—NSF2 and N=SF2—NSOF2 yields the disubstituted derivatives of SF6, F2SNSF4NSF2 and F2SNSF4NSOF2 (12), respectively, both of which exist in the reaction mixtures as cis- and trans-isomers90 (13) and (14). The 

Sulphur-Nitrogen Compounds.—Linear Compounds. The crystal structures of the polymeric metal (SN)jt, polythiazyl, prepared by the solid-state, room-temperature polymerization of S2N2 over 3 days, followed by heating at 75 °C for 2 h, and of S2N2 have been determined. Polythiazyl consists of an almost planar chain of 

spectrum and force fields of matrix-isolated cis-thionylimide, HNSO, have been studied. Photolysis of cis-HNSO leads to the formation of four products these have been identified, and the following reaction scheme was proposed for the photolytically indueed process cis-HNSO cis-HOSN cis-HSNO + trans-HSNOSNO. It has also been shown that trons-HNSO may be obtained by the low-energy ( 3000 A) photolysis of cis-HNSO in an argon matrix i.r. spectra of the two isomers were compared and a further photolysis product was thought to be the radical NSO. 

The unstable compound silylsulphinylamine, SiH NSO, has been prepared by the reaction of MejGeNSO or Bu SoNSO with SiHjBr, or of (H SiX N with SOCI2. Electron-diffraction studies show that the skeleton is bent at nitrogen and at sulphur, has an unusually long Si—N bond, and is non-planar. 

The compound S(=NSiMe,)3 has been shown to react with trifluoroacetic anhydride to form (10) and (11), which are nitrogen analogues of sulphur trioxide. 

The nitrogen analogue of sulphuric acid (12) may be prepared by the reaction of F2S(=NSiMe3)2 and (Me3Sn)2NMe. 

Sulphur-Nitrogen Compounds.—Linear Molecules. The synthesis of the stable bis(trifluoromethyl)sulphimide, (CF3)2S=NH, by the reaction of ammonia with bis(trifluoromethyl)sulphur difluoride in the presence of a primary amine, has been reported. The reaction of (CF3)2S=NH with n-butyl-lithium gives a white crystalline solid, (CF3)2S=NLi, which is a useful precursor to a variety of stable substituted sulphimides [reaction (8)], thus providing an opportunity to compare the reactivities and general properties of the (CF3)2S=N— system with that of (CF3)2C=N—. 

Fluorosulphinyl imidosulphur oxide difluoride (9) has been prepared [equation (9)]. The compound, which is the first representative of the hitherto unknown series of halogenosulphinyl imidosulphuroxide difiuorides, gives an unusual F n.m.r. spectrum. Instead of the expected doublet and triplet, it contains a quartet 

NN -Di-t-butylsulphurdi-imide (10) and iV-t-butyl-N -phenylsulphurdi-imide react with halogeno- and organo-sulphonyl isocyanates (11) to form IV-organyl-iV -sulphonylsulphurdi-imides (12) and t-butyl isocyanate [equation (10)]. At 

The aminomercaptosulphurdi-imides (13) have been prepared by the reaction of monosilylated sulphurdi-imides (14) with aminosulphenic acid chlorides. On reaction of (14) with dichlorosulphane, the sulphur di-imidosulphanes (15) are formed.  

The thermal decomposition of bis(pyrrolid-l-yl) disulphide has been studied over the temperature range 45—68 C. The results indicate a relatively weak S—S bond in bis(dialkylamino) disulphides and appreciable stability for the thionitrox-ide radicals (R2NS ). The kinetics of the disappearance of sulphonic acid in 

Intramolecular Processes. Two studies of axial-equatorial exchange in sulphur tetrafluoride have been published. Provided that the sulphur tetrafluoride is carefully purified it is claimed that the data are in good agreement with the Berry pseudorotation mechanism. The presence of impurities readily leads to intermolecular fluorine exchange. It has been claimed that the rate of exchange (in the absence of hydrogen fluoride) is the same in the liquid phase ( =11.2 kcal mol 0 as in the gas phase (E a =11.7 kcal mol ). 

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Candlin JP, Wilkins RG. Sulphur-nitrogen compounds. Part I. The hydrolysis of sulphamate ion in perchloric acid. J Chem Soc 1960 4236-4241. 

As previously pointed out, only sulphur functional groups with a highly symmetric electronic environment have been extensively characterized sulphones, sulphonates and to a lesser extent thiols, sulphides, sulphoxides and sulphur-nitrogen compounds such as sulphimides, sulphoximides and sulpho-namides. 

Sulphur-nitrogen compounds. 33S spectra of some sulphimides, sulphox-imides and sulphonamides29 64 65 have been reported, but the available data are not sufficient for a detailed discussion of the correlation between chemical shifts and molecular structure (Table A.6). 

The preparation of new sulphur-nitrogen compounds by the reaction of bis-(trimethylsilyl)sulphur di-imide (21) has been described.97 N-Chloro-N -tri-methylsilyl-sulphur di-imide (22) was prepared by the reaction of (21) with chlorine. 

These classes of compounds were the first used during the industrial revolution to improve the performance of machinery and were developed to improve the scuffing load of gear lubricants. Examples of typical structures of sulphur/nitrogen compounds which have found application are given in Fig. 3.12. 

Fig. 3.12 Chemical structures of some typical sulphur and sulphur-nitrogen compounds...

Parts 2 and 3 of the comprehensive review of the chemistry of thiazole have appearedthese include chapters on meso-ionic thiazoles and on cyanine dyes derived from thiazolium salts, and also one on selenazole and its derivatives. The chemistry of selenazole is also included in a review of selenium-nitrogen heterocycles. An account of the chemistry of thiazolidin-4-ones (which includes 2,4-diones but not rhodanine and isorhodanine) updates an earlier review. Reviews on cyclic sulphur-nitrogen compounds and on the synthesis and transformations of nitrogen- and sulphur-containing bicyclic heterocycles have appeared. More general reviews, which contain chemistry relevant to this section, cover reactions based on the onium salts of aza-aromatics, the synthesis of... 

Sulphur Di-imides.—Preparation and Properties of SN). This and related sulphur-nitrogen compounds have created interest both in their preparation and their physical properties (see Vol. 5, p. 103). Pyrolysis of S4N4 gives either (SN) or depending on the reaction conditions. - The physical and spectroscopic... 

Beavon, D. K and Brocoff, J. C., 1976, Recent Advances in the Beavon Sulfur Removal Process and the Stretford Process, Proceedings Second International Conference on Control of Gaseous Sulphur Nitrogen Compound Emissions, University of Salford, Salford (Brit.), Vol. 2, April 10. 

Anantharaj R, Banerjee T (2013) Thermodynamic properties of l-ethyl-3-methylimi-dazolium methanesulphonate with aromatic sulphur, nitrogen compounds at T = 298.15-323.15 K and P = 1 bar. Can J Chem Eng 97 245-256... 

The molecular structure of iVA -dimethylsulphurdi-imide was studied in the gas phase. The preparation, properties, and structures of a selection of di-, tri-, and tetra-co-ordinate cyclic sulphur-nitrogen compounds have been discussed. ... 

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