1- -4-nitrobenzene COMPOUND INDEX

Abstract—The viscosities, electrical conductivities, densities and refractive indexes of the binary systems of sulphuric acid with nitromethane, nitrobenzene and o-, m- and p-nitrotoluene have been investigated at 25° and 40°C. It has been shown that the forma tion of addition compounds according to the equation ... 

The investigation of viscosities, electrical conductivities, refractive indexes and densities of binary liquid systems of sulphuric acid with nitromethane, nitrobenzene and 0-, m and p-nitrotoluene was made in order to obtain a clearer picture of the behaviour of these binary mixtures, regarding the stability of the addition compounds formed between the components. The application of these methods of physicochemical analysis to a number of binary systems with sulphuric acid [1, 2, 3] has enabled us to get some idea of the way in which the formation and stability of addition compounds affects the liquid phase properties of these systems. The binary systems of sulphuric acid with mononitrocompounds are particularly suitable for comparison with each other, because of the close similarity of the liquid media in these systems, due to comparable values of dielectric constants and liquid phase properties of the mononitrocompounds. The stability of the addition compounds in these systems in the crystalline phase [4] has... 

Refractive indexes of these systems are given in Fig. 3 and in Tables 10-13, They all show positive deviations from additivity in volume fractions of the components, which increase in the order nitrobenzene < m-nitroi oluene < o-nitrotoluene. This confirms that the addition compounds formed by these aromatic nitrocompounds with sulphuric acid are more and more stable in this order, which is the order of increasing basicities. Rathex unexpectedly, however, the system with nitromethane shows high positive deviations from additivity, which equal those in the system with. o-nitrotoluene, This fact might be due to the small dimensions of the nitromethane molecules, which are therefore Jess likely to cause the disruption of the structure of sulphuric acid and thus U lower the Tefractive indexes of the mixtures, than the larger molecules of the aromatic nitrocompounds. 

Maricich, T. J. et al., J. Amer. Chem. Soc., 1974, 96, 7771, 7776 Benzene-, p-nitrobenzene-, and p-toluene-sulfinyl azides are thermally unstable, decomposing explosively when warmed alone or as cone, solutions. They may be prepared safely and handled as solutions at —20°C or below. The isolated solids may be stored at —80°C, but benzenesulfinyl azide explodes at 11°C, and p-toluenesul-finyl azide at 8°C. Individually indexed compounds are ... 

The compound consists of colorless crystals which melt at 35.7°. A supercooled melt shows a refractive index = 1.5313. The compound is very sensitive toward hydrolysis. It is readily soluble in benzene, nitrobenzene, and tetrachloroethane. 

Imidodisulfuric acid chloride forms colorless crystals which hydrolyze very rapidly in moist air they melt at 37°, boil at 115°/4 mm. and at 55°/0.03 mm., and have a refractive index ny> = 1.4948. The compound is readily soluble in organic solvents such as benzene or nitrobenzene. Hydrolysis in alkaline medium leads to imidodisulfate in acidic medium, sulfamic acid and sulfuric acid are formed. 

Another guiding principle to the CA index is that of inversion, whereby the subject is usually the chemical substance of which the compound is a derivative. For instance, "trinitrobenzene is indexed as "Benzene, 1,3,5-trinitro- and not as "Trinitrobenzene, though there may be a reference such as "Nitrobenzene, see Benzene, nitro-. ... 

Most refractometers are designed so that circulating water at a constant temperature can maintain the prisms at 20°C. If this temperature-control system is not used or if the water is not at 20°C, a temperature correction must be made. Although the magnitude of the temperature correction may vary from one class of compound to another, a value of 0.00045 per degree Celsius is a useful approximation for most substances. The index of refraction of a substance decreases with increasing temperature. Therefore, add the correction to the observed n value for temperatures higher than 20°C and subtract it for temperatures lower than 20°C. For example, the reported value for nitrobenzene is 1.5529. One would observe a value at 25°C of 1.5506. The temperature correction would be made as follows ... 

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