L. A. Kazitsyna

Synthesis, structure, and infrared spectra of aryldiazonium halogenoborates and tetraphenylborates

1. Diazonium halogenoborates and tetraphenylborates of the type p-YC6H4N2BX4, where Y=CH3O, CH3, Br, H, NO2, and X=Cl, Br, C2H5 have been obtained. 2. The ionic structure of the above-mentioned compounds has been shown by means of their infrared spectra in the 480–1400 cm−1 region, where the characteristic intense and broad absorption bands corresponding to the anions [BF4]−, [BCl4]−, and [BBr4]· are observed. 3. The infrared absorption spectra in the 2200–2350 cm1region of 19 diazonium halogenoborates and tetraphenylborates, and the corresponding aryldiazonium chlorides and bromides, have been recorded. 4. The frequency of the N≡N triple bond depends on the electronegativity of the anion and shifts systematically as this diminishes.

Spectra of aryldiazonium chlorides and the structure of diazonium cations

1. The structure of aryldiazonium cations was discussed, bringing in methods of IR and UV spectroscopy, x-ray diffraction study, and the MO LCAO method. 2. Both solid aryldiazoniums and their solutions are characterized by the presence of a triple bond in the diazonium group and a positive charge localized on both nitrogen atoms. 3. A difference of the UV spectra of the ortho- and meta-isomers from the spectra of the para-isomers was demonstrated for aryldiazonium cations. 4. The influence of the nature of the substituent upon the UV spectra of the aryldiazonium cations was investigated, and it was shown that the basic absorption band in the spectra of phenyldiazonium cations experiences a bathochromic shift with increasing electron-donor strength of the substituent in aryldiazonium cations. 5. It was shown by the MO LCAO method that the nature of the diazonium group (the presence of a triple bond and a delocalized positive charge on the two nitrogen atoms) is retained when any substituent is introduced, including the dimethylamino group.

Infrared absorption spectra of solutions of diazonium salts in the region of 2200–2300 cm−1

1. The behavior of diazonium salts in solutions was studied by means of the IR absorption spectra in the region of 2200–2300 cm−1. Diazonium salts are dissociated into ions in dimethylformamide, methanol, acetone, and ethyl acetate. 2. In dilute solutions the frequency of the valence vibrations of the triple bond does not depend on the character of the anion. When the concentration is increased (40–60%), it varies according to the nature of the anion. 3. The frequency of the valence vibrations of the triple bond of the diazo cation depends little on the polarity of the solvent. The addition of certain inorganic salts to the solutions somewhat reduces this frequency; of the salts studied, FeCl3 and SbCl3 cause the greatest reduction.

Effect of electron-donor properties of substituents and solvents on vibrational spectra of p-nitrobenzenes

Conclusions1.We analyzed the changes in the frequencies and integral intensities of the νsNO2 vibrations in the IR spectra of some nitrophenol, nitrothiophenol, and nitroaniline derivatives. An explanation was proposed for the reasons of the doublet structure of νsNO2, which appears in the spectra of many nitro compounds.2.A relation was shown to exist between the spectral changes and the donor properties of the substituents or solvents.

Spectroscopic study of a series of phenylmercury derivatives of nitroanilines

Conclusions1.The sequence of changes in the electron-donor properties of the following groups in p-nitroanilines and their PhHg derivatives was established from the positions of the long-wave bands in the electron spectra and the νasNO2 frequencies and integral intensities of the νAr and νsNO2 bands in the IR spectra:2.The electron-donor properties of the XHgPh groups in phenylmercury derivatives of p-nitrothiophenol, p-nitrophenol, and p-nitroaniline change in the following order: SHgPh < OHgPh <NHHgPh.3.The H atom is the coordination center with DMSO in the PhHg derivatives of p-nitroaniline; the Hg atom, in the o-nitroaniline derivative.4.A quantitative evaluation of the complexing process with DMSO and dissociation in DMSO is given for the compounds studied.

Electron donor capacity of certain compounds of trivalent phosphorus, containing P-O and P-N bonds

1. The electron donor capacity with respect to H-acid increases in the series from the complete amide of phosphorous acid. 2. The frequency shift and intensity of the absorption bands of H-complexes of derivatives of trivalent phosphorus are lower than for the corresponding esters and amines. 3. The change in the rate of alcoholysis and phenolysis was characterized quantitatively as a function of the strength of the H-acid and the number of amide groups in the molecule.

Spectral investigation of the electron-donor capacity of triphenyl derivatives of elements of group VB

1. An investigation of hydrogen bonds with phenol permits a quantitative evaluation of the changes in the electron-donor capacity in the series of triphenyl derivatives of elements of group VB. 2. The energy of the H-complexes with respect to the heteroatom varies in the series P> Sb ∼ As > N; the energy of theπ-complexes increases in the same series.

Specteal investigation of the electron-donating ability of triethyl phosphite as a method of evaluating the purity of phosphites

1. A method was proposed for evaluation of the purity of phosphite from the absorption band of the H-complex. 2. The electron-donating ability of triethyl phosphite in relation to alcohols is less than that of orthoformic ester.

Investigation of para-, meta-, and ortho- chlorophenyldiazonium double salts by nuclear quadrupole resonance and infrared spectroscopy

1. Both the NQR frequencies and the infrared frequencies vCN2 depend slightly on the nature of the metal anion in chloride complexes of diazonium double salts. 2. A relationship has been established between the NQR and vCN2 infrared frequencies and the nature of the halide in the complex anion. 3. The metal-halogen bond in the complex anion is substantially covalent.

Para-amino-substituted diazonium compounds and acid-base equilibrium of aryldiazonium cations

1. The absorption of p-amino-substituted diazonium cations and the corresponding diazoimides (diazoimines) in the UV and IR spectra differs. 2. The conversion of amino-substituted diazonium cations to p-imidequinonediazides is a reversible reaction of dissociation of a weak acid. 3. p-N-Benzoylaminophenyldiazonium “bicarbonate,” synthesized by Morgan, represents a mixture of a diazonium chloride and p-diazoimide. 4. The strength of the acid (diazonium cations) depends upon the substituent in the amino group and decreases in the series of R: (NO23C6H2 > C6H5SO2 > C6H5CO> CH3CO. 5. The acid-base equilibrium of aryldiazonium cations was discussed.