Azoxy compoimds

FIGURE 5.7. Experimental dependences of the threshold voltage for Ka-pustin-Williams domains with a planar initial orientation (a) on the anisotropy of the electrical conductivity and (b) on the dielectric anisotropy for doped MBBA (circles) and for mixture A of azoxy compoimds (crosses). Calculation is according to a two-dimensional theory (curve 1) and a one-dimensional theory (curve 2). The threshold of the Prederiks effect for doped MBBA is shown in curve 3, which represents the theory, while the squares represent the experimental measurements [31]. 

A black predpitate of silver indicates a nitro-, nitroso-, azo- or azoxy-compoimd. 

Azoxy-con unds (RN(0)NR ). Heat a very small quantity (ca 1 mg) of the substance with 1 ml of concentrated sulphuric add at 90 for 30 seconds. Azoxy-compoimds are converted to hydroxy-azo-compounds, which possess rich orange or red-brown colours. 

Unsymmetrical azo- or azoxy-compoimds on reduction with tin and hydrochloric add produce a mixture of two amines, while hydrazo-compounds may yield amine(s) formed by normal reduction of the hydrazo-link and a diamine produced by a benzidine rearrangement. Nitro-samines, on reduction with tin and acid, give the secondary amines from which they were derived.)... 

The examples are azoxy compounds, nitro compoimds or ozone. 

D) Reduction of Nitrobenzene to Azoxybenzene. In alkaline media the reduction of nitro compoimds may give azoxy (RN=N(0)R), azo (RN=NR), or hydrazo (RNHNHR), depending on the amount and type of reducing agent used. 

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