P-azoxyphenetole

One of the few exceptions are molecules like p-azoxyanisol, p-azoxyphenetol and anisaldazine, which form anisotropic liquids and for which Wolf [Physik and Chemie der Grenzjlachen. Vol. 1, Springer (1957), p. 44) reports y T) curves with kinks. 

Fig. 2.1.8. Orientational order parameters versus temperature (a) theoretical curves for v = 1.15,1.18 and 1.20 (b) experimental curves of i defined by (2.3.1) for p-azoxyanisole (PAA), anisaldazine and p-azoxyphenetole (PAP).< > The dashed portions of the curves represent supercooled regions. (After reference 5.)...

THE 100 /CM-1/ ABSORPTION BAND OF P-AZOXYPHENETOLE IN THE SOLID LIQUID-CRYSTAL, AND LIQUID STATES. //ENGLISH TRANSUTION OF OPTIKA I SPEKTROSKOPIYA 24/4/613-4,1968.//... 

Several electrohydrodynamic effects are known. The most important effect is dynamic scattering as described in 1968 by the RCA liquid crystal group [60]. Already in 1918 Bjornstahl [61] reported measurements on the extinction of light transmitted through a nematic liquid crystal under the influence of an electric field. With a 6.2 mm thick layer of p-azoxyphenetole, he observed a threshold field of 100 V/cm, above which the extinction increased sharply. 

Figure 18. Chromatographic separation of xylene, ethylbenzene, toluene and benzene using nematic p,p -azoxyphenetole as stationary phase (values taken from Ref. [132]).

Fig. 18 shows, however, that excellent separation is achieved if one uses nematic p,p -azoxyphenetoL The so-called separation factor... 

The existence of liquid crystal was known when the Austrian chemist Friedrich Reinitzer discovered a strange phenomenon of two distinct melting points on a cholesterol substance back in 1888. The solid crystal melted into cloudy Uquid at 145.5 C until the cloudiness disappeared and changed to a clear transparent Uquid at 178.5 C. The term Uquid crystal was introduced by Otto Lehmarm when he discovered in 1890 that ammonium oleate and p-azoxyphenetole showed turbid states between the extremely crystalline and the truly isotropic fluid state. This phenomenon was challenged for almost half of a century by some scientists because they previously knew of three states of matter, but the concept was Anally accepted and supported through conclusive experiments and theories. 

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