Tetraselenafulvalene structure

Tetraselenafulvalenes, tetramethyl-Raman spectra, 6, 954, 955 structure, 6, 950 UV spectra, 6, 952 Tetraselenafulvalenes, tetraphenyl-synthesis, 6, 963 1,3,5,7-T etrasilaadamantane formation, 1, 622 Tetrasilabicyclo[3.3. l]octane synthesis, I, 622 T etratellurafulvalenes IR spectra, 6, 954... 

The structure, reactivity and synthesis of the l,4,5,8-tetrahydro-l,4,5,8-tetrachal-cogenafulvalenes containing selenium and tellurium are also considered in this chapter. These structures are summarized in Scheme 2 and correspond to C6S2Se2 systems (dithiadiselenafulvalenes), C6SSe3 systems (thiatriselenafulvalenes), C6Se4 systems (tetraselenafulvalenes) and CeTe4 systems (tetratellurafulvalenes). 

The structure of the 1,3-diselenolylium ion has been investigated for radical-cation salts of tetraselenafulvalenes, materials useful as organic conductors and semiconductors. These compounds are discussed in Chapter 1.13. 

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.

Tetrathiafulvalenes.—Preparations of ever more elaborate compounds of this class have been announced. Coupling of the dithiolethiones (293 n = 2 or 3) by means of triethyl phosphite affords the tetracyclic derivatives (294) °° mixtures of the dithioleselones (295) and (296) give good yields of the crossed product (297) in this reaction.The tetraselenafulvalene (299) is obtained by photolysis of 3,4-diphenyl-l,3-diselenole-2-thione (298). Even cyclophanes containing the tetrathiafulvalene structure have been reported thus compound (300), on sequential treatment with methyl iodide, sodium borohydride, and fluoroboric acid-acetic anhydride, affords a mixture of the tetrathiafulvalenophanes (301) and (302), ° and the paracyclophanes (304) and (305) result from the para-substituted benzene (303). 

Corfleld, P.W.R. La Placa, S.J. Structure of the charge-transfer salt 2,2, 5,5 -tetraselenafulvalene-7,7,8,8-tetra-cyano-p-quinodimethane (TSeF-TCNQ). Acta Crystallogr., B 1996. 52 (2). 384-387. 

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