Diazonium character, diazo compounds

Kekule Formula.—These facts led Kekule to suggest a second formula in which the nitrogen atoms are both trivalent and in the same relationship to each other and the ring as they are in azo benzene. The formula is CeHs—N=N—Cl, benzene diazonium chloride. For some time this was the accepted formula for, if we put it in the reactions which we have written for the formation of diazo compounds and for their conversion into azo compounds and into hydrazines, we find that it is satisfactory. It does not agree, however, with the true salt character of benzene diazonium chloride nor the strongly basic nature of the hydroxide compound, the free diazo benzene. In every respect the neutral salts, e.g., benzene diazonium chloride and the free diazo... 

Such a reaction agrees perfectly with the new formula which has been generally accepted as expressing the constitution of the free diazo base and the salts. The base thus takes the name benzene diazonium hydroxide and the salts, e.g., the chloride, benzene diazonium chloride signifying their ammonium character. The new formula does not, however, fit the reactions by which diazo. compounds are converted into azo or amino azo compounds nor the reduction of diazo benzene to phenyl hydrazine. Thus we have two formulas neither of which... 

Di(methylsulfonyl)diazomethane allowed to react 24 hrs. at room tmp. with 2 moles a-morpholinostyrene in chloroform l,6-dimorpholino-l,6-diphenyl-3,4-diaza-1,3,5-hexatriene. Y ca. 65%. - Alkenylamines hardly react with ordinary diazoalkanes. However, they react easily with diazo compounds that have a pronounced diazonium character. U. Schollkopf, E. Wiskott, and K. Riedel, Ang. Ch. 80, 153 (1968). 

This is, however, a weak electrophile compared with species such as N02 and will normally only attack highly reactive aromatic compounds such as phenols and amines it is thus without effect on the otherwise highly reactive PhOMe. Introduction of electron-withdrawing groups into the o- or p-positions of the diazonium cation enhances its electrophilic character, however, by increasing the positive charge on the diazo group ... 

The 2-diazo-4,6-dinitrophenol (dinol, diazol, DDNP, DDNPh, or DADNPh) is the first-ever synthesized diazonium compound. Its synthesis is attributed to Griess [1] who prepared it by introducing nitric oxides into an alcoholic solution of 2-amino-4,6-dinitrophenol (picramic acid) [1,2]. Its explosive character was, however, first reported more than 30 years later in 1892 by Lenze [3]. 

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