Trithiol

Dicyano-l,2,3-trithiole 2-oxide (143) has been prepared from the silver salt of 2,3-dimercaptomaleonitrile (142) and thionyl chloride (66HC(2l-i)67). Similarly, the reaction of ethylene glycol (144) with thionyl chloride gave 1,3,2-dioxathiolane 2-oxide (145), the parent compound of saturated five-membered cyclic sulfites (see Chapter 4.33). 

Polyisoprene can be UV or e-beam cured [43,44]. The 3,4 units are particularly prone to crosslinking at low dose [45]. SIS and SBS are also crosslinkable, even conventional linear materials with low vinyl content however, small amounts of liquid trithiol or triacrylate compounds speed cure dramatically [44]. Like UV, e-beam cure is strongly affected by tackifier choice. Hydrogenated, non-aromatic resins provide much less interference with cure [36,37]. 

Photolysis of the 1,2,3-trithiole 42 in argon matrix (20 K) gave an electronic spectrum exhibiting the absorption maxima at 455 and 340 nm. Tlie spirodithiirane 43 and the thiosulfoxide 44 were believed to be responsible to these absorptions (89TL2955). 

As already described, oxidation of sodium mercaptomaleiioiiitrile (146) formed the dithiete 145, though it was not isolable (62JA4746, 62JA4756, 62JA4772). Decomposition of the trithiole 256 in DME at room temperature also produced 145, which dimerized to yield 257 as the hnal product or was trapped by ethyl vinyl ether to give 258 (62JA4772). 

LSs is the trithiolate cavitand ligand, l,3,5-tris((4,6-dimethyl-3-mercaptophenyl)thio)-2,4,6-tris(p-tolylthio)benzene(3-). 

Dithiazolyl radical 228 photochemically and thermally disproportionates to afford the 1,2,5-thiadiazole 229 and the unstable 1,2,3-trithiole 230 (Equation 54) <2000JCD3365>. Thermolysis of perfluoro-l,3A4(i2,2,4-benzodithiadia-zine 231 affords complex mixtures of heterocycles including perfluoro-2,l,3-benzothiadiazole 232 and 7,8-difluoro-benzo[l,2- 3,4-f ]bis[l,2,5]thiadiazole 233 (Equation 55) <2005EJI4099>. 

The favorable bismuth-sulfur bond translates into thermal and hydrolytic stability for the thiolates of bismuth, which are currently more numerous than the alkoxide derivatives (Table II). Various monomeric trithiolates have been identified, and most adopt predictable structural formulas, although the solid-state structures reveal interesting intermolecular and intramolecular interactions. 

Significant advances in the chemistry of these ring systems over the past 10 years include the first unambiguous detection, and characterization by microwave spectroscopy as 1,2,3-trioxolane, of the primary ozonide from ethene and ozone (cf. Section 4.15.3.2), and the introduction of 1,3,2-dioxathiolane 2,2-dioxides as epoxide equivalents in organic synthesis (cf. Section 4.15.5.3). Advances have also been made in the synthesis and characterization of the chemistry of 1,2,3-trithiolanes and 1,2,3-trithioles. 

C2O3] trioxolane, [C2S3] trithiolane or trithiole, [C2O2S] dioxathiolane or dioxathiole, [C2OS2] oxadithiolane or oxadithiole. 

In the 1,2,3-trithiole series, 1,2,3-trithiole 2-oxide (29) was obtained in 39% yield from the reaction of 2,2-dimethyl-1,3,2-dithiagermole (112) with thionyl chloride (Equation (25)) <88RTC440>. 1,3,2-Dioxathiolane 2-oxide (8) is conveniently prepared by reaction of 1,2-dihydroxyethane with either thionyl chloride <66HC(2l-l)l> or dimethyl sulfite <76CRV747> (Scheme 26). An alternative method. 

Cyclic silylphosphanes, see Silylphosphanes, phosphorus-rich, cyclic Cyclic sulfur-nitrogen compounds, see Sulfur-nitrogen compounds, cyclic Cyclic trithiolate ligand, 38 8-9 Cyclic voltammetry A. chroococcum Fd 1, 38 130-131 fullerene adducts, 44 19 nickel(ll) macrocyclic complexes, 44 112 Rieske proteins, 47 138, 139 Cyclidenes, as cobalt complex ligands, 44 282-284... 

Electron spin resonance (ESR) methods have been used to observe the formation of the radical cations and dications of benzoll,2- 4,5- ]bis[l,2,3]trithiole 13 and benzo[l,2-4 4,5- ]bis[l,2,3]dithiazole 17, and the experimental results confirm the ab initio calculations performed <2003EJ04902, 1997JA12136>. ESR has also been used to confirm the formation of superoxides upon photolysis of aryl benzobisthiazoles and aryl benzobisoxazoles in the presence of molecular oxygen <2003MM4699>. 

The chemical shifts and coupling constants have been determined for the antifungal agent tjipanazole A (see Section 10.21.12) and a derivative <1998MI723>. NMR methods have been used to verify the formation of the radical cation in a benzo[l,2-[Pg.1141]

Photolysis of these benzynes at 266 nm leads to production of 3,6-difluoro- and 3,6-bis(trifluoromethyl)-l,4-benzdiyne which are converted into the corresponding hexatriynes upon further irradiation at 266 nm. 4,8-Diethylbenzo[l,2-r/ 4,5- ]bis[l,2,3]trithiole 86 undergoes photolytic degradation on irradiation with a high-pressure mercury lamp, without the requirement for an additional desulfurization reagent, to produce thianthrene 87 in low yield (Equation 21) <2000TL1801>. 

Diethylbenzo[l,2-i7 4,5- ]bis[l,2,3]trithiole 86 can be oxidized with MCPBA to produce the 1-sulfoxide 100 which undergoes further oxidation on reaction with deuterated sulfuric acid to produce a dication (Scheme 6) <2003EJ04902>. On quenching with water this dication gave a mixture of the T and 2-sulfoxides 100 and 101. 

A triplet state dimer of a benzofused 1,2,3-trithiole dication was postulated. However the occurrence of this high-spin dimer is strongly dependent on the nature of the solvent and the oxidant129. The 2,5-dimethoxy-4-methylphenyl moiety in which the additional charge and the single electron are stabilized in a quinoidal structure after one-electron oxidation has been utilized as a probe for electron delocalization when two of these moieties were connected either by a trimethylene, a 1,4-disubstituted phenylene or a biphenyl bridge130. 

Fast atom bombardment (FAB), as the name implies, involves bombarding a solution of the analyte in a matrix (most usually propane-1,2,3-triol, propane-1,2,3-trithiol, 2-nitrobenzyl alcohol or triethanolamine, Figure 5.4) with a beam of fast moving atoms, generally xenon atoms with energy in the range 6-9 keV (580-870 kJ mol ). 

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