Metallic conductivity that increases continuously up to 1.3 K and achieves values of over 500000 S cm−1 is exhibited by single crystals of the radical‐anion salt depicted here, which was prepared by electrocrystallization. The multidimensional electronic conductivity is discussed on the basis of the crystal structure. The CuI ions are arranged in chains, each of which is surrounded by four stacks of dicyanoquinonediimine radical anions (one negative charge per “dimer”).

A new class of quinone derivatives, the dicyanodiimines 2,21, and 23, has been synthesized by the reaction of the corresponding quinones with bis(trimethylsily1)carbodiimide (8) and titanium tetrachloride. A wide variety of substrates, even those which contain bulky groups and those which exhibit a strong influence on the redox potential, has been prepared. A route starting from p-phenylenediamines 4 via the N,N'-dicyanodiamines 6 has been found to be much more limited. The spectroscopic properties of compounds 2, 21, and 23 are discussed with respect to their synlanti isomerizations as well as substituent effects on their planarity. Mehrstufige reversible

und 2 mit X = 0, C(CN)z und N-CN eine deutliche Parallelitat zwischen den Reduktionspotentialen El und E2 und insbesondere E2 -El, ausgedruckt als Semichinonbildungskonstante KsEM 2*4).

Multistep, Reversible Redox Systems, XXXVI I). -11,11,12,12-Tetracyano-9,lO-anthraquinodimethane (TCNAQ) and its Derivatives: Synthesis and Redox PropertiesTitle compounds 3Ba -d are synthesized from the corresponding anthraquinones and malononitrile with titanium tetrachloride/pyridine. By comparison of the potentials and semiquinone formation constants of 1 B -3 B with those of the corresponding quinones 1 A -3 A strong distortion of the biscyanomethylene groups in 2B and especially 3 B is derived. A) SynthesenDie hohe elektrische Leitfahigkeit einiger Acceptor-Donator-Verbindungen, die 7,7,8,8-Tetracyan-1 ,Cchinodimethan (TCNQ, 1B) als Acceptor enthalten3), hat sowohl die Synthesen substituierter TCNQs4) als auch die des 9,9,10,10-Tetracyan-l ,4-naphthochinodimethanss) (2B) ausgelost. Die Synthese des 11,11.12,12-Tetracyan-9,10-anthrachinodimethans (TCNAQ. 3Ba) scheiterte bisher auf der letzten Stufe eines langeren Syntheseweges6).Wir beschreiben nun einen bequemen Zugang zu 3Ba und seinen Derivaten 3Bb-d aus den entsprechenden Anthrachinonen und Malononitril. Diese einfache Knoevenagel-Kondensation gelingt erstaunlich glatt, wenn man das bereits 1970 von Lehnert') beschriebene Reagens Titantetrachlorid/Pyridin im UberschuO einsetzt @. Selbst 3Bd, in dem die Dicyanmethylen-Gruppen stark verdrillt vorliegen mussen, entsteht noch in 19% Ausbeute. 3Ba-d sind an der h f t lagerstabile Festkorper, wobei 3Ba -c cine gelbe Farbe besitzen, wahrend 3Bd farblos ist.

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