nung vorliegen könnten; 3. schließlich TTF-Phane, bei denen die eine TTF-Gruppe meta-, die andere paracyclophan-. artig verknüpft ist (4, (9)

In the “metallic” conducting 1:1 complex of tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ), donor and acceptor molecules form separate stacks in the crystal. In order to enforce other TTF/TCNQ arrangements by altering the molecular architecture the phane‐like bridged TTF‐paracyclophanes (1), n = 3, and (2) were first synthesized. To do this a novel reaction sequence had to be developed which also facilitated synthesis of the tetrathiafulvalenophanes (3)/(4) (and the corresponding [2.2]‐derivatives). (3)/(4) and TCNQ form a 1:4 complex having a conductivity of σ = 5 × 10−3 to 10−2 [Ω cm]−1 (single crystal, long axis, 300 K).

Beweisend fur die Ringverkniipfung in (4) und (5)141 sind vor allem die NMR-Kopplungen zwischen H' und H2 (Tabelle I), die den Diederwinkeln von ca. 180" in (4) und 40" in (5) entsprechen. Tabelle 1 . Ausgewahlte 'H-NMR-Daren der Verbindungen (4)-(9) (in CDCL). Verb. 6-Werte [a] Kopplungen [Hz] H' H2 H'" H3' J1.2 J2.3,

Owing to its "metallic conductivity""] the crystalline 1 : 1 molecular complex of tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) is one of the most interesting organic electron donor-acceptor compounds. Other than in the usual crystal lattices of strong donor-acceptor complexes, in which the donor and acceptor molecules alternate within a stack, in the TTF-TCNQ crystal the components form separate stacks131. Whether the special conducting properties are connected with this difference in molecular structure cannot be established experimentally owing to the lack of other crystal modifications of the same complex. Since it appeared a priori very unlikely that the crystal structure of the TTF-TCNQ complex is optimal with respect to the electrical conductivity we tried to effect other TTF-TCNQ arrays in the crystal lattice by changing the molecular architecture. For example crystallization in alternating donor-acceptor stacking should be enforced if TTF and TCNQ are bonded to each other cyclophane-like as in (1) (n=3 or 4). Donor-acceptor cyclophanes with TCNQ as acceptor component have already been synthesized[41. For the incorporation of TTF in cyclophane structures, however, a novel reaction sequence had to be developed. As example we describe here the synthesis of the parent compounds of (l), namely [3]tetrathiafulvaleno[3]paracyclophane (2) and [4]tetrathiafulvaleno[4]paracyclophane (3).For the synthesis of (2), 4,4-@-phenylene)dibutyryl chloride (4)I'l (prepared by reaction of the corresponding dicarboxylic with thionyl chloride, 2 h, 90°C; 83% yield) was converted via the bis(diazoketone) (obtained on reaction with diazomethane in ether) into the bis(ch1oroketone) (5)"l (m.p. 70-71 "C; 51% yield) (sodium chloride, hydrochloric acid, methanol) [']. Reaction of (5) with potassium O-isopropyldithiocarbonate (acetone, 30 minutes' reflux) afforded the corresponding bis(0-isopropyldithiocarbonate) (6)l5] (m. p. 63-64 "C; 89% yield). Subsequent cyclization (70% perchloric acid, chloroform/ether, 1 : I)['] furnished the bis(l,3-dithiol-2-one) (71, which on reaction with phosphorus(v) sulfide (xylene, 2.5 h, 140 "C) gave the bis(l,3-dithiol-2-thione) (8)Is1 [m.p. 99-100°C; 10% yield based on (6)].141 151. X = t l f71> x = o 161, X = 5 -CS-OiPr 181, X = S f91, X:SMeIQ 8 [' I Prof.

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