1.2.3.4- Dithiadiazolyls

Electron diffraction studies provide valuable information about structures in the gas phase. Consequently, this method is important for chalcogen-nitrogen compounds that are liquids or gases at room temperature. The application of this technique has provided evidence for the monomeric structures of the 1,2,3,5-dithiadiazolyl radical [CEsCNSSN] (3.3) and the 1,3,2-dithiazolyl [CEsCSNSCCEs] (3.4), a... 

Dithiazolyl radicals have also attracted considerable attention recently as potential molecular conductors (Section 11.3.6). The advantage of these systems over 1,2,3,5-dithiadiazolyls lies in their relatively low disproportionation energies (Section 11.3.1). 

In solution, the phenyl derivative 12.29 (R = Ph) is fluxional. The mechanism of the fluxional process has been shown by an N NMR investigation of a partially N-labelled sample, Le., PhCN2 N3S3 ( N = 99% N), to involve a series of 1,3-nitrogen shifts (Section 4.8.4). Thermolysis or photolysis of 12.29 generates the corresponding 1,2,3,5-dithiadiazolyl radicals [RCNaSa]". ... 

Figure 3 Four modes of association of 1,2,3,5-dithiadiazolyl radicals (2)...

Dithiadiazolyl radicals are considered to be organic molecular magnets and conductors and therefore chemists display increasing interest. Treatment of... 

Figure 3.10 EPR spectra of (a) 1,3,2-dithiazolyl and (b) 1,2,3,5-dithiadiazolyl radicals both absorption and first-derivative spectra are shown.

When R = Bu or a polyfluorinated aryl group (4-XCgF4, X = Br, CN, NO2), the 1,2,3,5-dithiadiazolyl radicals [RCN2S2] exist as monomers, whose magnetic properties are of particular interest. The tert-butyl derivative 5.5 is an unusual example of a liquid that is paramagnetic at room temperature the... 

The preparation of 1,2,3,5-dithiadiazolyl radicals by rearrangement of the isomeric 1,3,2,4-dithiadiazolyl radicals in solution [86CC140 87CC69 92JCS(D)1277] will be described more fully in Section XXI.A.l. In the case of some multi-l,2,3,5-dithiadiazolyl radicals, this reaction occurs in the solid state on thermolysis (Section XXIII.G.3). However, this route is not a common preparative technique, since these radicals are more conveniently prepared by direct reduction of 2+ salts, as described in Section VII.B. 

Isotropic ESR Data for Substituted 1,2,3,5-Dithiadiazolyl Radicals (All Coupling Constants in Milli-Teslas)... 

Heterocyclic Bond Distances, Angles, and Intermolecular Sulfur-Sulfur Distances for 1,2,3,5-Dithiadiazolyls... 

---