Poly Sulfur Nitride

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. 

intermediate between single- and double-bond values the bond angles at sulfur and nitrogen are ca 106 and 120°, respectively.There are weak interactions between the polymer chains [d(S S) = 3.48 A] that play an important role in preventing a substantial Peierls distortion in the polymer chain. 

Although (SN) t does not react with water or acidic solutions, the sensitivity of this inorganic polymer to alkaline reagents and to oxidation imposes 

Partial bromination of (SN) with bromine vapour yields the blue-back polymer (SNBro.4)x, which has a room temperature conductivity higher than that of (SN) c- The bromine is present as tribromide (Brs ) anions and Br2 molecules intercalated between partially oxidised polymer chains. 

---

The conducting polymer poly(sulfur nitride) is unusual in that it is crystalline, consisting of chains of sulfur and nitrogen packed in parallel. 

Polymer and chain formation is another property of chalcogen-nitrogen compounds that distinguishes them from their oxygen analogues. In addition to the unique, superconducting poly(sulfur nitride) (SN) (1.24) (Section 14.2), a variety of poly(thiazyl) chains such as RS5N4R (1.25) (Section 14.3) have been characterized. Interest in these chains stems from their possible use as models for the behaviour of (SN) and as components in molecular materials, e.g., as molecular wires. 

M. M. Labes, P. Love and L. F. Nichols, Poly(sulfur nitride) A Metallic, Superconducting Polymer, Chem. Rev., 79, 1 (1979). 

A. J. Banister and I. B. Gorrell, Poly(sulfur nitride) The Fkst Polymeric Metal, Adv. Mater., 10, 1415 (1998). 

Another possible modification of poly(sulfur nitride) that is expected to produce conducting polymers is the replacement of alternating sulfur in the thiazyl chain by an RC unit, i.e., [(R)CNSN]x. This type of polymer would have five r-electrons per four atoms in the repeating unit and, consequently, would have a partially occupied conducting band. The prospect of tuning the electronic properties of this polymer by... 

See Trimethylsilyl azide Selenium halides See also Poly (sulfur nitride) See other nitrides See related N-S COMPOUNDS... 

The endothermic nitride is susceptible to explosive decomposition on friction, shock or heating above 100°C [1], Explosion is violent if initiated by a detonator [2], Sensitivity toward heat and shock increases with purity. Preparative precautions have been detailed [3], and further improvements in safety procedures and handling described [4], An improved plasma pyrolysis procedure to produce poly (sulfur nitride) films has been described [5], Light crushing of a small sample of impure material (m.p. below 160°C, supposedly of relatively low sensitivity) prior to purification by sublimation led to a violent explosion [6] and a restatement of the need [4] for adequate precautions. Explosive sensitivity tests have shown it to be more sensitive to impact and friction than is lead azide, used in detonators. Spark-sensitivity is, however, relatively low [7],... 

SN)X can act as an efficient barrier electrode in ZnS junctions, increasing the quantum efficiency of the blue emission by a factor of 100 over gold.14 It can also be used to increase the efficiency of GaAs solar cells by up to 35%. Metal ions interact more strongly with a poly(sulfur nitride) surface than with other metal electrodes. This property has stimulated investigations of possible applications of (SN)X as an electrode material. 

Polysulfoxides, 23 733-735 optically active, 23 735 Polysulfoximines, 23 745-746 Poly(sulfur nitride), as organic semiconductor, 22 212 Polytellurides, 24 408 Poly-Tergent, commercial defoamer,... 

Ethoxy-l-iodo-3-butene, 2449 Hexamethylenetetramine tetraiodide, 2471 (Hydroxy)(oxo)(phenyl)-A3-iodanium perchlorate, 2299 Iodinated poly(sulfur nitride), 4622... 

Iodinated poly(sulfur nitride), 4622 Lead nitride, 4753... 

Poly(selenium nitride), 4730 Poly(sulfur nitride), 4728 Potassium nitride, 4671... 

V-Fluoroiminosulfur tetrafluoride, 4357 5-Hydrazino-1,2,3,4-thiatriazole, 0462 Iodinated poly(sulfur nitride), 4622 Mercury(I) thionitrosylate, 4610... 

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. 

Fibrous glass Poly(sulfur nitride) Poly(boron nitride) Silicon carbide... 

Solid-state (topochemical) polymerization of cyclic disulfur dinitride to poly(sulfur nitride) (or polythiazyl), -fSN, occurs on standing at ambient temperature or higher [Banister and Gorrell, 1998 Labes et al., 1979 Ray, 1978]. Disulfur dinitride is obtained by sublimation of tetrasulfur tetranitride. Polythiazyl is a potentially useful material, since it behaves like a metal. It has an electrical conductivity at room temperature about the same order of magnitude as a metal like mercury and is a superconductor at 0.3°C. Polythiazyl also has high light reflectivity and good thermal conductivity. However, it is insoluble and infusible, which prevents its practical utilization. 

Banister AJ, Gorrell IB (1998) Poly(sulfur nitride) the first polymeric metal. Adv Mater 10 1415-1429... 

It should be noted that inorganic rings play a crucial role as monomers for the preparation of both polysiloxanes and polyphosphazenes and they are also utilised for making polysilanes. Inorganic rings have also been used as key precursors to several other inorganic polymer systems [e.g. poly(sulfur nitride) and polythionylphosphazenes]. 

---