Tetracyanoquinodimethane derivatives

Murata T, Saito G, Nishimura K, Enomoto Y, Honda G, Shimizu Y, Matsui S, Sakata M, Drozdova 00, Yakushi K (2008) Complex formation between a nucleobase and tetracyanoquinodimethane derivatives crystal structures and transport properties of charge transfer solids of cytosine. Bull Chem Soc Jpn 81 331-344... 

Through reduction or oxidation of the molecule by a dopant molecule. Atoms or molecules with high electron affinity, such as iodine, antimony pentafluoride (SbCls), or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), may oxidize a typical organic semiconductor such as poly(p-phenylene) derivatives, leaving them positively charged. Reduction, i.e., addition of an electron, may be obtained by doping with alkali metals. 

Morita Y, Miyazaki E, Umemoto Y, Fukui K, Nakasuji K (2006) Two-dimensional networks of ethylenedithiotetrathiafulvalene derivatives with the hydrogen-bonded functionality of uracil, and channel structure of its tetracyanoquinodimethane complex. J Org Chem 71 5631-5637... 

The aim of the study was to create high-sensitive point-contact type gas sensors based on derivatives of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and to test them in analysis of exhaled air for diagnosis and monitoring of human organism state. 

Fig. 3. Isolatable />-xylylene derivatives (12), Thiele s hydrocarbon - 1904 [26392-12-1] (13), tetracyanoquinodimethane [1518-16-7] (TCNQ) (14), tetrakis(methoxycarbonyl)-quinodimethan [65649-20-9] (15), tetrakis(ethylsulfonyl)quinodimethan [84928-90-5].

True CT complexes are formed between unsaturated electron acceptors, among which the derivatives with cyano and nitro groups predominate. The most common strong electron acceptors are 1,2,4,5-tetracyanobenzene, 7,7,8,8-tetracyanoquinodimethane (1), tetracyano-p-benzoquinone (2), tetracyanoethylene (TCNE) (3) and many electron-donor... 

Only a few X-ray crystal structure determinations on 1,3-dithioles have been carried out. Some typical bond lengths and bond angles of the tetrathiafulvalene (5), l,3-dithiole-2-thione derivative (6) and 1,3-dithiolanes (7) and (8) are given in Tables 2 and 3, respectively. Also bond lengths and bond angles of the radical cation of tetrathiafulvalene in the tetrathiafulvalene-7,7,8,8-tetracyanoquinodimethane complex have been determined <74AX(B)763>. 

L. R. Melby, Substituted quinodimethans VIII. Salts derived from the 7,7,8,8-tetracyanoquinodimethan anion-radical and benzologues of quaternary pyrazinium cations, Can J. Chem. 43 1448-1453 (1965). 

Tetracyanoquinodimethane (TCNQ) and many of its derivatives are easily reduced to anions of the type TCNQ-, which form salts with various cations. With many cations, e.g., tetrathiafulvalene cations (TTF+), and N-methyl phenazinium cations (NMP+), the TCNQ- anions form electronically conducting salts (- molecular metals, -> charge-transfer complexes) that can be used as electrodes, especially because of their electrocatalytic properties (- biosensors, -> electrocatalysis, -> molecular metals) [i,ii]. TCNQ undergoes insertion electrochemical reactions (-> insertion electrochemistry) leading to TCNQ salts [iii, iv]. Polymers... 

Tetrathiafulvalene electrodes — Tetrathiafulvalene (TTF) and many of its derivatives are easily oxidized to form cations of the type TTF+. With various anions, most prominent is the tetracyanoquinodimethane anion (TCNQ-), these cations form - charge-transfer complexes, i.e., salts with metal-like conductivities (- molecular metals). These salts are used in electrochemistry as electrodes or to modify the surface of electrodes, for the purpose of achieving desirable electrocatalytic properties (- electrocatalysis). Tetrathiafulvalene-substituted polystyrenes have also been synthesized and used as modified electrodes [ii]. 

Tetracyanoethylene (tone) and 7,7,8,8-tetracyanoquinodimethane (tcnq) both form adducts with stannocene and plumbocene that are of uncertain structure. The stannocene derivatives SnCp2 (tcne) (n = 1 or 2) and SnCp2 (tcnq) are proposed to be cyclopentadienyl 7r-charge transfer complexes (42). The plumbocene derivatives PbCp2(tcne) (n = 0.5 or 1) and PbCp2(tcnq) apparently involve charge transfer and are proposed to be polymeric (41). 

The preparation and properties of the charge transfer salt between azonia derivative (2 and 246) and tetracyanoquinodimethane (TCNQ) were reported (88MI2). Wang and Jones reported that acridizinium salt underwent single crystal — single crystal photodimerization (87T1273). 

After the discovery of the interesting electrical properties of tetrathia-fulvalene (TTF)-tetracyanoquinodimethane (TCNQ) complexes, many TTF derivatives have been prepared by reaction of 1,3-dithiolium salts with tertiary amines. This reaction has been interpreted as proceding by deprotonation of a 1,3-dithiolium cation to the corresponding carbene which in turn reacts as a nucleophile on the C-2 of another 1,3-dithiolium cation. This topic having been recently reviewed, we refer in Table 309,310 Qjjjy jQ papers subsequent to this review. ... 

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