Superconducting polymers

Keywords C60 Fullerene Fullerite Fulleride C60 polymer Superconductivity Density functional theory... 

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). 

Electrochemical methods may also be used in the synthesis of chalcogen-nitrogen compounds. For example, the electrochemical reduction of salts of the [SsNs]" cation (Section 5.3.9) in SO2 or CH2CI2 at low temperatures produces microcrystals of the superconducting polymer (SN). ... 

Pike, G., Pierson, H. O., Mullendore, A., and Schirber, J., Superconducting Thin Film Niobium Carbonitrides on Carbon Fibers, / / . Polymer Symp., No. 29, pp. 71-81, John Wiley Sons, New York (1976)... 

Interestingly, if the C50 fullerene doped by alkali metals is rapidly cooled down to the liquid nitrogen temperature, polymerization does not occur. Only monomeric anion-radical salts are obtained. Warming up these monomers to 80-160 K results in dimerization polymerization does not take place. The dimer (KCgo)2 is dielectric (Pekker et al. 1995). It has been shown that the tris(anion)-radical Cgo can polymerize too. Particularly, Na2CsCgo forms a polymer that maintains superconducting properties (Mizuki et al. 1994). 

In the last ten years, particularly since the discovery of superconductivity in (SN) polymer , several molecules, especially and... 

A whole new chemistry has been developed around this discovery, and the unusual properties have given rise to suggestions that it could be made into products for a superconducting material, a three-dimensional polymer, new catalysts, new materials with unusual electrical and optical properties and very high mechanical strength, sensors, nanotubes, nanowires, and so on. At this moment, there are, as yet, no products based on the fullerene on the market. 

So far no organic polymers have been confirmed to show superconductivity, in spite of several unconfirmed polymer superconductors mentioned below. It should be remembered that the sample should be well oriented, otherwise the disorder inherent to organic polymers will destroy the superconductivity. 

Labes MM, Love P, Nichols LF (1979) Polysulfur nitride - a metallic, superconducting polymer. Chem Rev 79 1-15... 

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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