TMTSF 4,4’,5,5 -tetramethyl

Figure 1 Prototype molecules TTF (tetrathiafulvalene and TMTSF (tetramethyl-tetraselenafulvalene) which are used for the elaboration of organic conductors TTF-TCNQ or superconductors (TMTSF)2X. View of the crystal structure of some molecular superconductors (a) (TMTSF)2PF6 (b) (alkali)3 C (c) (BEDT-TTF)2Cu(SCN)2 side view (d) view along the axis perpendicular to the conducting plane.

Research in the area of new synthetic metal (synmetal) superconductors continues to be stimulated by rapid developments in the chemistry and physics of these materials.1 Synmetals are unique in that they have metallic properties even though they contain no metals. However, this field remains very much materials limited because, as yet, it is not possible to predict which new materials will exhibit metallic properties. This situation is improving because structure-property correlations have been developed recently that may be used to predict likely candidates for superconductivity in the 4,4 j5,5 -tetramethyl-2,2 -bi-l-3-diselenolylidene, often called the tetra-methyltetraselenafulvalene (TMTSF) class of materials.2... 

Fig. 10.1 The molecular structure of tetramethyl-tetraselena-fulvalene, TMTSF for short. The molecule is planar, which favours a stacking of the molecules within the crystal.

H. Bruce Goodbrand (Xerox Research Centre of Canada) having 3,4-dimethylphenyl substituents have been abbreviated as Xy, aryl groups with para substituents are prefixed by p, tetrathiafulvalene has been abbreviated as TTF, and its tetramethyl tetraseleno analogue as TMTSF. 

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