Yu. K. Maksyutin

NQR study of hydrogen bonded trichloroacetic acid complexes

1. The35Cl NQR method was used to study 10 complexes of trichloroacetic acid with lactams, ketones, amides, and amines. 2. All of the studied compounds are complexes with a hydrogen bond. 3. The relation between the basicity of the donor and the average frequency shift is linear. 4. Employing the method of complete neglect of differential overlapping (second variation), it was shown by calculation that the relation between the negative charges on the chlorine atoms and the negative charge on the oxygen atom of the hydroxyl of the acceptor molecule is nonlinear.

Calculation of complexes with charge transfer and their spectra by the pariser-parr-pople method considering configurational interaction

1. Theπ-π complexes of benzene and pyridine with chloranil and tetracyanoethylene were calculated. 2. The calculated absorption spectra of the benzene complexes are in good agreement with the experimental data. 3. The model of theπ-π complex cannot explain the mechanism of the reaction of ion radical formation in the interaction of pyridine with chloranil and tetracyanoethylene.

Microcalorimetric investigation of the interaction of polystyrene, poly-N-vinylcarbazole, and their monomer analogs with antimony trichloride

1. The equilibrium constants and thermodynamic parameters of complexes of SbCl3 with cumene, polystyrene, N-propylearbazole, and poly-N-vinylcarbazole were measured by the method of microcalorimetry. The thermodynamic parameters of the complexes are related by an isokinetic function; the isoequilibrium temperature is 179°K. 2. The higher equilibrium constants of the polymer complexes in comparison with the monomer complexes are due to steric factors.

Investigation of SbCl5-donor complexes with charge transfer by the NQR method

1. The NQR-121Sb and123Sb spectra of two complexes and35Cl spectra of six complexes of antimony pentachloride were investigated. 2. The degree of charge transfer and the distribution of charge in the acceptor molecule was calculated according to the Daily-Townes theory. 3. The influence of electronic and steric factors on the NQR-35Cl spectra was investigated.

NQR spectra of complexes of antimony trichloride with π-donors

1. The NQR spectra of121Sb,123Sb, and35Cl were investigated for 26 complexes of SbCl3 with 12 aromatic donors. 2. The quadrupole interaction constants in the complexes vary correspondingly to the change in the ionization potentials of the donors. 3. The increased value of the quadrupole interaction constant for the complex of SbCl3 with polystyrene in comparison with complexes of SbCl3 with ethylbenzene and cumene is evidently due to the lower degree of charge transfer on account of steric interactions of the acceptor molecules with the polymer chain. 4. The degree of charge transfer in the investigated complexes was estimated.

Cl35 nuclear quadrupole resonance spectra of some organotin chlorides

1. The Cl35NQR spectra of some organotin chlorides were investigated. 2. The dependence between the Cl35NQR frequencies and the quadrupole splitting constants of Sn119 in the Mossbauer spectra was obtained. 3. The electron structures of the investigated compounds were discussed.

NQR spectra of Cl35 in complexes of stannic chloride with monochlorodimethyl ether and benzyl chloride

The NQR spectra of Cl35 of complexes (1:2) of stannic chloride with monochlorodimethyl ether and benzyl chloride were investigated. Both complexes have an octahedral structure with a cis-arrangement of the donor molecules.

NQR spectra of Bi209 in complexes of BiCl3 with p-donors

1. The NQR spectra of Bi209 in complexes of BiCl3 with diethyl ether, anisole, acetone, and acetonitrile were investigated. 2. The investigated complexes are comparatively weak. 3. Changes in the quadrupole interaction constants and the parameters of the asymmetry in the series of these complexes depend to a substantial degree on the geometrical structure of the complexes.

Investigation of cis-trans-isomerization of complexes of stannic chloride with n-donors by the NQR method

1. The shape of the NQR spectra of octahedral complexes of halides of metals of group IV with n-donors was considered by the molecular orbital method. The shifts of the NQR frequencies and the nature of the splitting of the NQR spectra of cis- and trans-isomers differ. The large splitting of the spectrum of the cis-isomer is due to the chemical nonequivalence of the axial and equatorial halogen atoms. 2. The NQR spectra of a number of complexes of stannic chloride with n-donors were investigated. On the basis of the nature of the splittings of the spectra, a number of conclusions were drawn on cis-transisomerism in the investigated compounds. The possibility of determining the composition and structure of the complexes by the NQR method was demonstrated.

Br79 and Br81 NQR spectra of aluminum bromide complexes with some p-donors

1. The Br79 and Br81 NQR spectra of five aluminum bromide complexes with some p-donors were investigated. 2. The direction of the quadrupole frequency shifts in these complexes is caused by a charge transfer. The magnitude of the shift is determined by the extent of the charge transfer. 3. The steric factor leads to a high-frequency shift of the NQR lines, and also the large splitting in the spectra.