Sulfur Monochloride Research Articles

Synthesis of 1,3,4-Thiadiazoles from Aldehyde Hydrazones

Reaction of p-tolualdehyde hydrazone with disulfur dichloride in the presence of DBU gave 2,5-di (p-tolyl)-1,3,4-thiadiazole (1a) in 54% yield. Phenyldiazomethane also reacted with disulfur dichloride to afford 2,5-diphenyl-1,3,4-thiadiazole (1b) in 80% yield.

Prototypal dithiazolodithiazolyl radicals: synthesis, structures, and transport properties.

New synthetic routes to 1,2,3-dithiazolo-1,2,3-dithiazolylium salts, based on double Herz condensations of N-alkylated 2,6-diaminopyridinium salts with sulfur monochloride, have been developed. The two prototypal 1,2,3-dithiazolo-1,2,3-dithiazolyl radicals HBPMe and HBPEt have been prepared and characterized in solution by cyclic voltammetry and EPR spectroscopy. Measured electrochemical cell potentials and computed (B3LYP/6-31G) gas-phase disproportionation enthalpies favor a low on-site Coulombic repulsion energy U in the solid state. The crystal structures of HBPR (R = Me, Et) have been determined by X-ray crystallography (at 293 K). Both consist of slipped pi-stacks of undimerized radicals, with many close intermolecular S- - -S contacts. Magnetic, conductivity, and optical measurements have been performed and the results interpreted in light of extended Hückel band calculations. The crystalline materials are paramagnetic above 100 K, with room-temperature conductivities sigma(RT) of 10(-5)-10(-6) S cm(-1); the slightly greater conductivity of the R = Et compound can be associated with a more well developed band structure. We suggest a Mott-Hubbard insulator ground state for these materials, with an on-site Coulomb repulsion energy U of about 1.0 eV.

Synthesis and characterization of polystyrene- block-polyisoprene nanofibers with different crosslinking densities

Polystyrene- block-polyisoprene or PS- b-PI with 74 styrene and 230 isoprene units was prepared by anionic polymerization. The diblock formed cylindrical micelles with PI core and PS corona in a PS-selective solvent N, N-dimethylacetamide. Nanofibers with different crosslinking densities were obtained after PI core crosslinking with differing amounts of sulfur monochloride. The nanofibers were characterized by elemental analysis, FTIR, transmission electron microscopy, and light scattering.

Water‐dispersible porous polyisoprene‐block‐poly(acrylic acid) microspheres

AbstractTwo polyisoprene‐block‐poly(tert‐butyl acrylate) (PI‐b‐PtBA) samples and a poly(tert‐butyl acrylate) (PtBA) homopolymer (hPtBA) were prepared by anionic polymerization and characterized by light scattering, size exclusion chromatography, and NMR. The tert‐butyl groups were removed from one of the diblocks to yield amphiphilic polyisoprene‐block‐poly(acrylic acid) (PI‐b‐PAA). PI‐b‐PAA was then used as the surfactant to disperse dichloromethane containing PI‐b‐PtBA and hPtBA at different weight ratios as oil droplets in water. Solid microspheres containing segregated polyisoprene (PI) and PtBA/hPtBA domains were obtained after dichloromethane evaporation. Permanent microspheres were obtained after PI domain crosslinking with sulfur monochloride. Porous microspheres were produced after the hydrolysis of PtBA and the extraction of the homopoly(acrylic acid) chains. The shape and connectivity of the poly(acrylic acid)‐lined pores were tuned by changes in the PtBA/hPtBA content in the precursor microspheres. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2785–2793, 2003

Optimization of the Synthesis of Symmetric Aromatic Tri‐ and Tetrasulfides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Unprecedented conversion of triethylamine and disulfur dichloride into a thienopentathiepin and a heptathiocane.

[reaction: see text] In a remarkable cascade reaction, triethylamine is converted into the thienopentathiepin 2a and the heptathiocane 3a by a preequilibrated solution of disulfur dichloride and DABCO in chloroform.

Optimization of the synthesis of symmetric aromatic tri- and tetrasulfides.

The reaction of aromatic thiols with sulfur dichloride and sulfur monochloride to form the corresponding aromatic trisulfides, 2a-d, and tetrasulfides, 3a-d, has been optimized with respect to yield and purity. The use of pyridine as an amine base and the use of freshly distilled sulfur monochloride (S(2)Cl(2)) serve as important alterations to the synthetic method. Their physical properties have been characterized, revealing some discrepancies with the literature.

Synthesis and electrochemical behavior of poly N, N′-dithiobis (1,3-phenylenediamine)

A novel organic disulfide, N, N′-dithiobis(3-nitroaniline)(1) was prepared by the reaction of 3-nitroaniline with sulfur monochloride in chloroform. Compound 1 was reduced by zinc powder to give N, N′-dithiobis(1,3-phenylenediamine) (2). Poly N, N′-dithiobis (1,3-phenylenediamine) (3) was prepared by electrochemical polymerization of compound 2 and its basic electrochemical behavior is discussed.

Millimeter-Wave Spectroscopy of ClBS: An Improved Evaluation of the Equilibrium Structure of Chlorothioborine

The rotational spectrum of the unstable ClBS molecule has been investigated in the millimeter-wave region, from 80 to 195 GHz. A high-temperature reaction between crystalline boron and disulfur dichloride vapor was used to produce the molecule in a flow pyrolysis system. Eight different isotopic species were studied measuring lines in the ground and excited vibrational states 01 10 (ClBS bend), 10 00 (ClB stretch), 02 00, 02 20, and 00 01 (BS stretch). The analysis of the spectra has been performed taking simultaneously into account both the Fermi resonance between the 10 00 and 02 00 states, and l-type resonance effects in the v 2=2 vibrational state. This procedure allowed us to calculate directly deperturbed rotational constants, from which the equilibrium rotational constant of seven isotopic variants could be accurately determined yielding a much improved evaluation of the equilibrium structure of chlorothioborine: r e (ClB)=1.6806±0.0001 Å and r e (BS)=1.6049±0.0001 Å. The equilibrium structures of ClBS and of the related molecules HBS, FBS, HCP, FCP, and ClCP have been also theo-retically evaluated by high-level CCSD(T) calculations performed using cc-pVTZ, cc-pVQZ, and cc-pV5Z basis sets. The different trends respectively observed for the BS and CP bond lengths in the XBS and XCP triatomic molecules are discussed.

Practical Synthesis of Thiirene 1‐Oxides that Possess Two Bulky Alkyl Substituents.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Preparation of 4-benzylsulfanyl[1,2,3,5]dithiadiazol-1-ylium chlorides: potential precursors to meso-ionic 1,2,3,5-dithiadiazolium-4-thiolate

Treatment of S-benzyl-iso-thiuronium chlorides with sulfur monochloride (S2Cl2) gives the corresponding S-benzyl-1,2,3,5-thiadiazolium chlorides 2 as deep red crystalline compounds. The structure of the p-chlorobenzyl derivative 2a has been confirmed by X-ray crystallography. Attempts to generate the unknown type-B meso-ionic compound 1,2,3,5-dithiadiazolium-4-thiolate 1 by reaction of these salts with nucleophiles were unsuccessful. AM1 semi-empirical molecular orbital calculations suggest that, although the meso-ionic structure corresponds to a local energy minimum, acyclic valence tautomers could equilibrate in solution and lead to further reaction.

New chemistry of bis[1,2]dithiolo[1,4]thiazines and bis[1,2]dithiolopyrroles

The new long-chain or branched-chain N-alkyl bisdithiolothiazines 2a,b, 3a,c, and 4a,c have been prepared by the appropriate one-pot reaction of the corresponding N- alkyldiisopropylamines and disulfur dichloride. The bisdithiolopyrroles 5a-f were obtained by thermal sulfur extrusion from their corresponding bisdithiolothiazines or by an alternative and faster method consisting of S-oxidation by dimethyldioxyrane and SO extrusion. The cycloadditions of a bisdithiolothiazine ketothione and benzyne or p-tolylsulfonylacetylene were studied and the new cycloadducts 7 and 9 (Z +E) were characterized.

Competing dissociation channels in the photolysis of S2Cl2 at 235 nm

The photodissociation of disulfur dichloride (S2Cl2) at 235 nm has been studied by three-dimensional (3D) imaging of the chlorine product recoil in its ground state P3/22[Cl] and excited spin–orbit state P1/22[Cl*] employing the resonance enhanced multiphoton ionization and time-of-flight techniques. The photodissociation proceeds mainly along the three channels forming S2+2Cl (1), S2Cl+Cl (2), and 2 SCl (3) photoproducts where slow and fast Cl fragments are released in (1) and (2), respectively. The relative yield of channel (1) with respect to channel (2) was determined to be 1.2:1.0. The yield of Cl*, φ(Cl*)=P(Cl*)/[P(Cl)+P(Cl*)], was found to be 0.35. The obtained state-specific velocity distributions of Cl and Cl* are mainly different in the high energy range: For Cl* the two dissociation channels are almost equally present, whereas in the case of ground state Cl the contribution of dissociation channel (2) is of minor importance. The dependence of the anisotropy parameter β on the fragment recoil velocity was directly determined due to the novel technique where the 3D momentum vector of a single reaction product is observed. For both spin–orbit states the anisotropy parameters differ for slow, intermediate, and fast chlorine atoms. The observed β values change from zero to slightly negative values up to positive values with increasing kinetic energy. These observations can be explained by two overlapping dissociation channels, where the two-body channel (2) releases the chlorine atom with high kinetic energy and a positive β parameter via an excited A1 state, whereas the three-body channel (1) proceeds mainly sequentially, where the first Cl atom is released with intermediate speed and a slightly negative β value via an excited B1 state, while the second Cl product atom in the decay of S2Cl is released isotropically with slow recoil velocities.

Highly sulfurated heterocycles via dithiiranes and trithietanes as key intermediates.

2,2,4,4-Tetramethyl-3-thioxocyclobutanone (8b) easily reacts with gaseous chlorine to yield the stable alpha-chloro sulfenyl chloride 10. The same product was obtained when 8b was treated either with phosphorus pentachloride (PCl(5)) or sulfuryl chloride (SO(2)Cl(2)) in CCl(4) solution. Sulfur dichloride (SCl(2)) reacts with 8b to give the alpha-chloro thiosulfenyl chloride 12 along with an almost equimolar amount of the trisulfide 13b. The less reactive disulfur dichloride (S(2)Cl(2)) was shown to react slowly with 8b and the symmetrical tetrasulfide 15 was found as the exclusive product. The pure thiosulfenyl chloride 12 added to adamantanethione (8c) yielded the unsymmetrical trisulfide 13c. When 12 was treated with thioacetic acid, the acetylated trisulfide 17 was formed in high yield. "Unzipping" reactions with the acetylated disulfide 16 and trisulfide 17 with morpholine in THF at -40 degrees C led to the formation of mixtures of two sulfur-rich heterocycles identified as the pentathiepane 6b and the hexathiepane 7b. A mixture of analogous products was obtained when alpha-chloro sulfenyl chloride 10 was treated with sodium sulfide in anhydrous THF at -40 degrees C. The formation of 6b and 7b is believed to occur via the intermediate dithiirane 1b and/or the isomeric thiosulfine 2b. In the case of 17 the reaction starts probably with the formation of a nonisolable tetrathiane 18b as presented in Scheme 5.

Swelling and Mechanical Properties of Solution-Crosslinked Poly(isobutylene) Gels

We prepared several series of poly(isobutylene) (PIB) gels starting from butyl rubber in dilute toluene solutions using sulfur monochloride as a crosslinking agent. Solution and suspension-crosslinking techniques were used for the preparation of PIB gels in the form of rods, membranes, and beads in the size range of 1 to 3 mm. The gels were subjected to dynamic and equilibrium swelling measurements in toluene and cyclohexane as well as to the elasticity tests. Depending on the amounts of sulfur monochloride and butyl rubber in the crosslinking solution, PIB gels with different swelling capacities and elastic moduli were synthesized. The swelling ratio of the gels first increased rapidly with increasing swelling time but then decreased until an equilibrium was obtained. This unusual swelling behavior was accompanied with an increase of the elastic moduli of the gels during the swelling process. The results were explained with the post-crosslinking reactions taking place during the swelling process of PIB gels. By using the theory of equilibrium swelling, the number of segments in the network chains and the polymer-solvent interaction parameters were calculated for PIB gels prepared under various reaction conditions.

Practical synthesis of thiirene 1‐oxides that possess two bulky alkyl substituents

AbstractAcetylenes that possess two bulky alkyl substituents reacted with sulfur dichloride to furnish the corresponding 2,3‐dialkyl‐2,3‐dichlorothiiranes (5) nearly quantitatively. The alkaline hydrolysis of 5 afforded 2,3‐dialkylthiirene 1‐oxides (10) in high yields. These two reactions could be successively carried out in one flask, and 2,3‐di‐tert‐butyl‐, 2,3‐di‐(1‐adamantyl)‐, and 2‐(1‐adamantyl)‐3‐tert‐butylthiirene 1‐oxides (10a–c) were obtained in 70, 80, and 90% yields, respectively, based on the starting acetylenes, thus providing the most convenient synthesis of thiirene 1‐oxides. Disulfur dichloride also reacted with acetylenes to give 5 in good yields with the elimination of one sulfur atom. Although the alkaline hydrolysis of 5 provided 10 exclusively, acid hydrolysis gave a mixture of α‐oxothioketone 9 and thiirene 1‐oxide 10 in modest yields. All thiirene 1‐oxides 10a–c isomerized to produce α‐oxothioketones 9 in high yields when heated in boiling toluene. Reactions of a bis‐acetylene (18) with disulfur dichloride and with sulfur dichloride gave a dihydropentathiepin (19) in high yields. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:424–430, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10070

Novel Synthesis and Thermal Ring Fission of 7-Aryl-1,2,3,4,5,7-pentathiazocanes

Abstract Treatment of 1,5,3,7-dithiadiazocanes 1 with bromine-elemental sulfur or disulfur dichloride (S2Cl2) afforded 1,2,3,4,5,7-pentathiazocanes 3, and heating of 3 caused unusual thermal ring fission to give an inseparable mixture of polysulfide chains bearing a thioformamide moiety on each terminal.

ChemInform Abstract: Synthesis of Taurine Analogues. Part 1. 2‐Aminosulfonic Acids from Alkene—Sulfur Monochloride Adducts.

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Elastic behaviour of solution cross-linked poly(isobutylene) gels under large compression

Modulus of elasticity of loosely cross-linked poly(isobutylene) gels are measured under large compressive deformations. Gels of perfect spherical shape are prepared by the suspension cross-linking technique of dilute toluene solutions of butyl rubber using sulfur monochloride as a cross-linking agent. Compressive deformation is applied by a calibrated stainless steel cantilever to spherical poly(isobutylene) beads of sizes ca. 1.0–4.0 mm in diameter swollen in toluene. The relationship between force and deformation is obtained by using the constitutive relations from molecular theory of elasticity. Moduli are measured immediately after applying compression, and after full relaxation which obtains after solvent exudes the gels under compression. The instantaneous moduli are an order of magnitude larger than equilibrium moduli. Results of mechanical measurements, which are presently of a preliminary type, are compared with those from independent thermodynamic estimates of shear moduli.

Solution Cross-Linked Poly(isobutylene) Gels: Synthesis and Swelling Behavior

We prepared several series of PIB gels starting from butyl rubber in dilute toluene solutions using sulfur monochloride as a cross-linking agent. By using solution and suspension cross-linking techniques, PIB gels in the form of rods or beads in the size range of 0.1−2 mm were prepared and subjected to swelling in solvent−nonsolvent mixtures. The swelling capacity of the gels in toluene increased with decreasing concentration of sulfur monochloride or butyl rubber in the organic phase. The solubility parameter of the solution cross-linked PIB gels was found to be 16.8 ± 0.8 MPa0.5, in accord with the reported value for bulk cross-linked gels. In toluene−methanol mixtures, PIB gels with 4% cross-linker content exhibited an abrupt deswelling when the toluene content of the external solution was decreased from 97 to 90%. By using the theory of equilibrium swelling, it was shown that the gel passes through critical conditions as the quality of the solvent becomes poorer.