Phenazinium salts

The anodic oxidation of phenazine N,AT-dioxide at a platinum anode in benzonitrile led to the intermediate radical-cation, which dimerizes.320,321 5-Substituted 5,10-dihydrophenazines are oxidized in two successive one-electron steps or one two-electron step in aqueous acetone.322 The corresponding phenazinium salts were formed as the ultimate oxidation products. 

The formal exchange of two methine groups in positions 9 and 10 in anthracene by nitrogen atoms would result in dibenzo-l,4-diazine, i.e. phenazine. The commonly accepted numbering system (used by Chemical Abstracts) is presented in structural formula I, which differs from the older literature, in which the nitrogen atoms were labelled as the 9- and 10-positions. Quaternization of either heterocyclic nitrogen atom changes the phenazine to its phenazinium salt in the earlier literature the name phenazonium salt was used. 

Although chemically and structurally quite different from phenazines, phenazinium salts can be prepared by analogous methods from A -substituted benzene-1,2-diamines. 

Dimethylaminoindamines undergo rapid intramolecular cyclization to give the 2,8-diamino-10,10-dimethyl-5,10-dihydrophenazinium ion which is slowly converted into the lO-methyl-phenazinium salt, a methyl group being eliminated as methanol." ... 

Phenazine oxide reacts with Grignard reagents to give phenazinium salts. ... 

Leow reported the use of a phenazinium salt, either phenazine ethosulfate or saffanin O, as a photocatalyst for the aerobic oxidative amidation of aromatic aldehydes with secondary amines to prepare the corresponding amides in good to high yields (Scheme 62) (140L5812).This method provides access to a more ecologically safe, mild, and inexpensive generation of benzamides. 

Directed synthesis of phenazinium salts N-Oxides as intermediates... 

Dimethyl sulfate added at 110-115° to a soln. of 2-phenylphenazine 10-oxide in nitrobenzene, after abatement of the exothermic reaction heated 10-12 min. at 125-130° in an oil bath, and the product isolated as the perchlorate 2-phenyl-5-methylphenazinium 10-oxide perchlorate. Y 85%.—Phenazinium salts of determined structure can be obtained through the above intermediates. F. e. s. Y. S. Rozum, 30, 1661 (1960) C. A. 55, 1631d. 

Phenazinium salts, directed synthesis 17, 989 Phenol (s. a. Sodium/phenol)... 

R. M. Metzger,N.E. Heimer,D. Gundel,H.Sixl,R. H.Harms,H.J. Keller,D. Nothe,and D.Wehe,Crystal and molecular structure andEPR spectra of thel 1 salt N-(l-butyl) phenazinium (NBP) 2, 2 -(2,3,5,6-tctrafluoro-2A5-cyclohcxadiene-l,4-diylidcnc)-bis-propanedinitrile (TCNQF4),/. Chem. Phys. 77 6203-6214 (1977). 

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... 

Various redox compounds that fulfil catalyst characteristics have been investigated in systems with recycling of NAD by electrocatalytic methods. Quinones, formed either by oxidation of carbon surfaces [143, 145] or adsorbed to the electrode surface [146, 147], phenazines [148, 149], phenoxazine derivatives such as Meldola Blue [182], 9-naphthoyl-Nile Blue [151, 152] and l,2-benzophenoxazine-7-one [153], and also the organic conducting salt N-methyl phenazinium tetracyanoquinodimethanide (TTF TCNQ") [154, 155], ferricinium ions [156, 157] and hexacyanoferrat(IIl) ions [158, 159] can act as catalysts for the electrochemical oxidation of NADH. It is assumed that in corresponding electron-transfer reactions a charge-transfer complex between the immobilized mediator and NADH is formed. The intermediate reduced redox mediator will be reoxidized electrochemically. Most systems mentioned, however, suffer from poor electrode stabilities. 

Phenazinium, 3-((7-((4-aminophenyl)amino)-5-phenylphenazinium-3-yl)amino)-5-phenyl-7-((5-phenyl-7-(phenylamino)phenazinium-3-yl)-amino)-, salt with chromic acid... 

N-acoxycyclimmonium salts azidocyclimmonium — azomethinium —, cyclic carbalkoxycyclimmonium — nitrocyclimmonium — phenazinium — pyridinium — quinaldinium — thiazolium —... 

The action of diazonium salts on thiazolidine-2,4-diones and rhodanines yields 5-arylazo-2,4-diones (271) resembling azo-rhodanines in spectral and other properties. Condensation products of phenazine and rhodanine of type (272) are formed in good yield by the nucleophilic attack of N-methylrhodanine on the appropriate phenazinium perchlorate. A ben-zothiazole residue may be similarly incorporated. ... 

Disulfophenyl)amino]-7-phenylsulfobenzo[d] phenazinium hydroxide inner salt. Azocarmine BX. C.I. Acid red 103. C.I. 50090... 

Phenylsulfo-5-[ 4-sulfopheny[)amino]benzo[aL phenazinium hydroxide inner salt. Rosiniduline. C.I. Acid red 101. C.l. 50085... 

Amino-3-sulfophenyl)amino]-7-[ethyl[ 3-sulfopheny[) methyl amino]-5- 4-sulfophenyl)phenazinium hydroxide inner salt. C.I. 50230. C.l. Acid blue 18... 

Phenyl-5,9-bis(phenylamino)-4J0-disulfohenzo[ a] phenazinium hydroxide inner salt. C.I. 50320. Acid blue 102 [6378-88-7]... 

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