V. I. Slovetskii

An investigation of the structure of salts of 1,1-dinitroalkanes and trinitromethane by spectral methods

An investigation of the infrared spectra showed that the salts (potassium, sodium, ammonium, and lithium) of 1,1-dinitroalkanes and trinitromethane have three absorption bands: ∼1480, ∼1210, and ∼1120 cm−1. The infrared spectra do not contain absorption bands characteristic of the C=N double bond or an uncharged nitro group. Therefore, it is confirmed that salts of 1,1-dinitroalkanes and trinitromethane do not contain a C=N bond, and that all the nitro groups are equivalent and participate equally in the formation of the anion.

Spectrophotometric determination of the dissociation constants of aliphatic nitro compounds

1. The dissociation constants of aliphatic nitro compounds may be found spectrophotometrically to a high degree of accuracy. 2. The dissociation constants of ten nitroalkanes have been measured at various temperatures (trinitromethane, 1,1-dinitroalkanes, and 1,1,3,3-tetranitroalkanes). 3. The acidity function H− has been found for hydrochloric acid in concentrations from 0.1–1.2 M. 4. Standard values of the enthalpy and entropy of the dissociation reactions of nitroalkanes have been calculated from the temperature dependence of the dissociation constants.

Dissociation constants of certain nitroalkanes in aqueous ethanol

1. The dissociation constants of dinitromethane, 1,1-dinitroethane, 1,1-dinitropropane, trinitro-methane, and 1,1,3,3-tetranitrobutane were determined in 50% ethanol at various temperatures (5–60°). 2. The activity coefficients of hydrochloric acid (0.001–0.1 M) in 50% ethanol were measured for various temperatures (5–60°). 3. The acidity function H was found for hydrochloric acid (0,3–1.5 M) in 50% ethanol. The acidity function H is practically independent of the temperature within the indicated limits (5–60°). 4. The standard values of the enthalpy, entropy, and free energy were calculated for the process of dissociation of the nitroalkanes studied in 50% ethanol on the basis of the temperature dependence of the dissociation constants.

Relationship between the inductive effect and values of the dissociation constants in the series of gem-dinitro compounds

In the series of gem-dinitro-compounds, a quantitative relationship was found between the dissociation constants and the induction constants of the radical substituents.

The decomposing action of light on aliphatic nitro compounds

Nitroalkanes and their salts in water solution are decomposed by the action of light, and this decomposition is stronger, the closer the wavelength of the light which illumines the substances is to the absorption maximum of the substance.

Quantitative relation between the induction constants of substituent radicals and the physical chemical properties of nitro compounds

1. The changes in the physical chemical properties studied in the series of nitroalkanes and their halogen derivatives is to a large degree determined by the induction constants of the substituent radicals. 2. With compounds of this series a quantitative relation was found between the induction constants of the substituent radicals, o*, and the spectroscopic characteristics, the dissociation constants, and the half-wave potentials in polarographic reduction.

Acid character of 1,1-dinitroalkanes and their spectra

On the basis of determinations of dissociation constants and a study of the spectra of eleven dinitroalkanes it was shown that there is a direct correlation between the acid character and the frequencies of C-H vibrations in the series of compounds RCH(NO2)2. A relation has therefore been found between the acid characters of these nitro compounds and their spectrum characteristics.