1.1.1- Tricyano compound

As expected for a tricyano compound, it is highly endothermic (AH°j (s) +348.1 kJ/mol, 3.78 kJ/g), so its stability seems dubious [1]. However, because of isomerisation to the acidic dicyano-enimine (NC)2C=C=NH, it is considerably stabilised and the silver and sodium salts surprisingly are described as stable [2],... 

Merrill and Kass presented a detailed theoretical study of substituent effects on the cyclopropenyl anion. Cyano substituents were found to be particularly effective in stabilizing the anion, and the tricyano compound was calculated to be stabilized by... 

A new class of heteroaromatic compound was introduced by the synthesis of a diphosphathienoquinone (20). It can be reduced to a semiquinone radical anion and dianion at lower potentials than phosphaalkenes. The ESR spectrum indicates that the two P atoms are not equivalent213. 2,4>6-Tricyano- 1,3,5-triazine undergoes dimerization to yield 4,4, 6,6 -tetracyano-2,2 -bitriazine214. 

These compounds are thermally stable. 2,4,6-Tricyano-l,3,5-triazine reacts rapidly with water to form cyanuric acid and hydrogen cyanide (equation 12) (59HC(13)1, p.170). 

The reaction of Q -cyano-/3-chlorocinnamonitrile 64 with KSCN, ROH, and active bromomethylene compounds (BrCH2X) gave the thieno[2,3-d]pyrimidine derivatives 65 [89EGP(D)273441]. Condensation of tetracyano-l,4-dithiin 66 with NaCN in THF produced 4,5,6-tricyano-thieno[2,3-d]pyrimidine-2-thiolate 67 (80JOC5113). 

Tricyanovinyl-N,N-dimethylaniline has been prepared by adding hydrogen cyanide to -dimethylaminobenzalmalono-nitrile and oxidizing the adduct.3 The present procedure, an adaptation of one that has been published,3 is the more convenient preparative method. It can be applied to a wide variety of secondary and tertiary aromatic amines to give />-tricyanovinyl-arylamines that, like the present one, are dyes.3 Other types of aromatic compounds also condense with tetracyanoethylene in this manner. Thus one can obtain 4-tricyano vinyl-2,6-dimethyl-phenol from 2,6-dimethylphenol, 2-tricyanovinylpyrrole from pyrrole, and 9-tricyanovinylphenanthrene from phenanthrene.4... 

On the other hand, a similar reaction of 5-acetyl-4-methyl- or 5-acetyl-2,4-dimethyloxazole leads to 2-acetyl-5-amino-l, 1,4-tricyano-3-methyl-cyclopentadiene (232), a yellow crystalline compound, in 60% yield. A mechanism of the formation of 232 has been proposed.883... 

A complex of l,l,3-tricyano-2-aminopropene (XXI) and riboflavin (entry 74, Table II) has been suggested to be of the charge-transfer type . Such a complex would be of interest in that (XXI) has been reported to block oxidative phosphorylation . A hypochromic effect is observed for the riboflavin maxima, but no new peak appears. The same note refers to charge-transfer complexes of tryptophan (a weak donor) and picric acid (a strong acceptor) with riboflavin. As one would anticipate a healthy contribution from dipolar structure (XXII) in the tricyanoaminopropene, it is not clear whether this compound should be a donor or acceptor (or alkylating agent). A donor-acceptor interpretation for the complex of (XXI) and riboflavin seems questionable. 

A hybrid acceptor compound of TCNQ and DCNQl has been prepared by reaction of benz[a]anthracene-7,12-dione (62) with malononitrile by using Lehnert s reagent to yield 10-(dicyanomethylene)-benz[a]an-throne (63). Further reaction with BTC led to the formation of the tricyano derivative (64) in a moderate yield as stable orange crystals (Scheme 1.13 pyr = pyridine). 

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