Sulfur -nitrogen polymers

Sulfur-Nitrogen Polymers Containing Three-Coordinate Sulfur(lV)... 

For example, there is considerable interest in the preparation of sulfur-nitrogen polymers that have organic substituents on the sulfur atoms.56 This could help alleviate the intractability problem mentioned, and could also give rise to a series of polymers that parallel the phosphazenes in their structural variability. A series of polymers with S-N backbones of this type has been prepared, but with oxygen atoms as some of the substituents. The basic structure has the repeat unit -RS(=0)(N)- or -FS(=0)(N)-but they have not yet been studied in detail. The fluorine-containing polymer, however, is known to be a tough elastomer which is unaffected by water, acids, or bases up to 100 °C.7... 

Sulfur-nitrogen-phosphorus polymers possess backbones which can be regarded as compositional hybrids of those present in sulfur-nitrogen polymers, such as the solid state polymer poly(sulfur nitride) [SN]X or polyoxothiazenes... 

Sulfur-nitrogen-phosphorus polymers possess backbones that can be regarded as compositional hybrids of those present in sulfur-nitrogen polymers, such as the solid-state polymer poly(sulfur nitride) [SNh or polyoxothiazenes [RS(0)=N]n and classical polyphosphazenes, [R2P=N] (1) (92). Poly(sulfur nitride), [SNh, possesses remarkable properties such as electrical conductivity at room temperature and superconductivity below 0.3 K (93). [SNh is insoluble and has a polymeric structure in the solid state with interchain S - S interactions. As these interactions are crucial to the properties of the material, [SNl is best regarded as a solid-state polymer rather than a polymeric material with discrete macromolecu-lar chains of the type discussed in this article. 

I. Manners, Sulfur-Nitrogen-Phosphorus Polymers, Coord. Chem. Rev., 137, 109 (1994). 

Although (SN)x does not react with water or acidic solutions, it slowly decomposes in alkaline solutions and it is readily oxidized. Partial bromination of (SN) or powdered S4N4 with bromine vapour yields the blue-black polymer (SNBro.4)x which has a room temperature conductivity of 2 x 10" cm . The sulfur-nitrogen chain in this... 

The discovery in 1973 that polysulfur nitride (SN)X, a polymer comprised only of non-metallic elements, behaves as a superconductor at 0.26 K sparked widespread interest in sulfur-nitrogen (S-N) chemistry. In the past 30 years, the field of inorganic S-N chemistry has reached maturity and interfaces with other areas of chemistry, e.g., theoretical chemistry, materials chemistry, organic synthesis, polymer chemistry and biochemistry, have been established and are under active development. This interest has been extended to Se-N and, to a lesser extent, Te-N systems. 

Sulfur nitride polymers [-(-S = N-)-], which have optical and electrical properties similar to those of metals, were first synthesized in 1910. These crystalline polymers, which are super-conducive at 0.25 K, may be produced at room temperature using the solid state polymerization of the dimer (S2N2). A dark blue-black amorphous paramagnetic form of poly(sulfur nitride) (structure 11.30) is produced by quenching the gaseous tetramer in liquid nitrogen. The polymer is produced on heating the tetramer to about 300°C. 

The exciting discovery of the metal-like properties and superconducting behaviour of the non-metallic polymer poly (sulfur nitride) (or polythiazyl), (SN), in 1973 sparked much activity in sulfur-nitrogen chemistry.This interest continues as a result of the prediction that molecular chains incorporating thiazyl units could serve as molecular wires in the development of nanoscale technology. 

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