HMTSF TNAP

Some materials are very sensitive to disorder [3]. In general, the low-temperature susceptibility follows x a T a (a5=3 0.6 to 0.9). (NMP)(TCNQ) and Qn(TCNQ)2 are examples of this effect, the disorder being intrinsic, attributed to the asymmetry of the cation. (HMTSF)(TNAP) has a similar behavior at low temperature, the disorder being attributed to the TNAP molecule. In (TTT)2I3+6 the disorder results from nonstoichiometry. Similar effects have been obtained when disorder is induced by irradiation... 

Q- TTF-TCNQ (above 58 K) TMTSF-TCNQ (black form) NMP-TCNQ TSF-TCNQ (above 40 K) HMTSF-TNAP TMTTF-TCNQ HMTTF-TCNQ... 

Fig. 1. Molecules that form conducting crystals described in this article. The left column contains the donors perylene (Per), tetrathiafulvalene (TTF), hexamethyl-enetetraselenafulvalene (HMTSF), tetramethyltetraselenafulvane (TMTSF), and bis(ethylenedithio)-TTF (BEDT-TTF or ET ). To the right are the acceptor molecules tetracyanoquinodimethane (TCNQ) and tetracyanonaphthalene (TNAP).

TTF-DETCNQ crystallizes in a triclinic lattice with each acceptor molecule surrounded by four donor molecules and vice versa /lo, 11/. In this respect, TTF-DETCNQ resembles TTF-TNAP /12/ and HMTSF-TCNQ /13/, which also have the "four-nearest-neighbours" structure and not the usual "herring-bone" with, only two nearest neighbours. 

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