Tricyanovinylation

Among other aromatic compounds that have been tricyanovinylated are phenanthrene (23), o-alkylphenols (24), pyrrole (23), indoles (23,25), 2-meth5lfuran (26), azulenes (26,27), diazocyclopentadiene (28), and a variety of phenyUiydrazones (26). 

Indole, 4,5,6,7-tetrahydro-4,7-dioxo-structure, 4, 303 Indole, tetrahydro-3-methyl-synthesis, 4, 109 Indole, 2-(2-thienyl)-nitration, 4, 211 Indole, 3-thio-synthesis, 4, 368 Indole, 2-thioalkyl-synthesis, 4, 152 Indole, 3-thiocyano-synthesis, 4, 368 Indole, 1-tosyloxy-rearrangement, 4, 302 Indole, 1,2,3-trialkyl-Mannich reactions, 4, 228 Indole, 3-(tricyanovinyl)-nucleophilic addition reactions, 4, 281 reactions... 

Tetracyanoethylene yields a colored it-complex with aromatic compounds in the case of aromatic amines, phenols and indoles these then react to yield the corresponding tricyanovinyl derivatives [3, 4]. 

Tricresyl phosphate, 11 493, 494 Tricyanocuprate(I), 7 578t Tricyanovinyl dyes, 9 258 Tricyclic encapsulating ligand, tetraprotonated form of, 24 44 cis,lrares-Tricyclodecanediamine physical properties of, 2 500t Tricyclohexyl citrate... 

In principle, the behaviour of any molecular species in forming donor-acceptor complexes depends on its ionization potential, electron affinity and polarizability. However, the donor (or acceptor) ability of a substance depends strongly on the requirements and properties of its partners. The same compound may act as a donor towards strong acceptor compounds or as an acceptor towards donor compounds. This is the case of the TT-amphoteric p-tricyanovinyl-AA/V-dimcthylaniline (41) which is a donor towards 2,4,7-trinitrofluorenone and an acceptor towards /V,/V-dirnclhy Ian Mine138. 

Thermal stability of these new high idf] chromophores is still a problem, especially those containing a tricyanovinyl gronp (FTC), and compromises need to be made against high and high thermal stability, as exhibited by (5.8). 

NaL -2 H2O (0.5 g, 1.7 mmol) is dissolved in water (100 mL). Concentrated aqueous HCl (11 M, 3 mL) is added dropwise with stirring. Immediately, a deep green crystalline solid separates, and the color of the solution changes from violet (A ax 550 nm) to red-violet (A ax 523 nm) on the formation in solution of HL, the 2-tricyanovinyl-3,4-dicyano-5-amino-17/-pyrrole. The solid (HL + HL) is then collected on filter paper, washed with water (3 x 10 mL), dried in air, and then heated in an oven at 70°C for 24 h. During this time the complete HL HL transformation occurs in the solid state, and pure HL is obtained (0.38 g, 95%). 

When all the tetracyanoethylene has been added, the reaction mixture is stirred at 45-50° for 10 minutes, and heat is supplied as needed by a water bath. />-Tricyanovinyl-N,N-dimethyl-aniline generally crystallizes out as a dark-blue solid during this period. At the end of the heating period, the mixture is chilled... 

The crude product is purified by recrystallization from 160-180 ml. of acetic acid. The solution (Note 1) is allowed to cool slowly to room temperature, and -tricyanovinyl-N,N-dimethyl-aniline is collected on a Buchner funnel and washed successively with 20 ml. of methanol and 40 ml. of ether. The product, 23-26 g. (52-58%), is obtained as dark-blue needles, m.p. 173-175° (Note 2). 

Indolizines also react readily with activated halides such as picryl chloride146 and tricyanovinyl chloride147 to form highly colored derivatives. 

Two molecular crystals were prepared with the intent to prepare organic ferromagnets. These are the nitronyl nitroxide 1 and l,3,5-tris(tricyanovinyl)benzene (2). 

We have recently prepared a new chromophoric and redox-responsive ionophore (4) containing a tricyanovinyl redox-active moiety (35) (Scheme 2). Electronic absorption spectra of (4) exhibit hypochromic shifts on binding Group IA and IIA metal cations and cyclic voltamme-tric electrochemical investigations reveal that (4) electrochemically recognizes Na+ and K+ guest cations, resulting in one-wave CV shifts of the tricyanovinyl reduction wave (80 and 20 mV, respectively) to more anodic potentials. 

The monobenzo compound (107 R1=R2 = H) forms a stable salt with methyl iodide. Reaction with TCNE results in elimination of hydrogen cyanide and formation of the tricyanovinyl derivative (107 R1 = C(CN)=C(CN)2, R2 = H) (67JA2626). 

The bicyclic species (111) are unknown but some reactions of the monobenzo (112) and dibenzo (113) species have been described and they closely resemble those of the isomeric betaines (107) and (108) (Section 4.37.4.4). Electrophilic substitution occurs on the ben-zenoid rings of compound (113) and treatment with methyl iodide slowly gives an adduct. The monobenzo derivative is more reactive, readily giving a methiodide and rapidly undergoing electrophilic substitution reactions. Reaction of compound (112 R = H) with TCNE results in elimination of hydrogen cyanide and formation of the tricyanovinyl derivative (112 R = C(CN)=C(CN)2) (67JA2633). 

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