V. E. Kataev

Vibrational spectra and the conformational composition of β-chloro- and β-bromophenetoles

ConclusionsAccording to the data from vibrational spectrospyco, chloro- and bromophenetole in the crystalline state remain in the gauche orientation of the C-O and C-Hal bonds.

Analysis of the anisotropic polarizability of molecules in the gas phase, liquids, and solutions: 2. The Kerr effect

Conclusions1.We have found correlations between series of molecular anisotropies measured by different methods.2.The internal field must be taken into account in determining molecular anisotropies in liquids and solutions. Use of the internal field factor (n2 + 2)2/9 provides the best agreement with gas-phase measurements.3.We suggest an equation for calculating optical anisotropies at infinite dilution with allowance for the internal field.

Steric structure of some 2-halogenated ethylbenzenes

Conclusions1.With the complex use of the methods of dipole moments, the Kerr effect, the Cotton-Mouton effect, and molecular mechanics, it was shown that the 2-halogenated ethylbenzenes studied in solutions of CC14 are an equilibrium mixture of approximately equally populated trans and gauche retainers on the C-C bond.2.In both conformations, the plane of the aromatic ring is close to shielding of the C-H bond.

Structure of several β-haloethyl aryl sulfides

ConclusionsThe average population of the conformation with trans orientation of the C-S and C-Hal bonds for the β-haloethyl aryl sulfides studied was found to be 80%.

Structure of several β-bromophenetoles

Conclusions1.The two-component equilibrium of conformers relative to the C-C bond in the p- and o, p-substituted β-bromophenetoles studied is shifted somewhat toward the trans conformer.2.Realization of the GG conformer with eclipsed Ar-O and C-Br groups is possible in the o-halo-β-bromophenetoles studied.

A structural study of several β-halophenetoles

Conclusions1.The GG form, in which the halogen atom is in direct proximity to the aromatic ring, participates in the conformational equilibrium in several to the β-halophenetoles studied. The occupancy of this form decreases upon the replacement of Cl by Br.2.The occupancy of conformations with trans orientation of the C-Hal and C-O bonds is 60%.

Polar properties and conformations of the methyl ethers of the ethylene halohydrins

Conformations with C-O and C-Hal bond counter-oriented parallel dipoles can be realized in the ethylene chloro- and ethylene bromohydrins.

Polarities, polarizabilities, and conformations of the 2-haloalkyl-1,3-dioxanes

1. n nConformations with trans orientation of the C-Hal bond of the axial halomethyl group, i.e., with parallel counter orientation of the C-O and C-Hal dipoles in the 1,3 po-sition, are realized in the 2,2-bis(chloromethyl)- and 2,2-bis(bromomethyl)-1,3-dioxanes (II) and (III). It has been shown that one of the realized conformers of these compounds has the C-Hal bonds in parallel orientation. n n n n n2. n nFor the dimethylacetal of bromoacetaldehyde there are probably two different structures, with the acetal group in trans-gauche or gauche-gauche conformation (the CH3 groups located on opposite sides of the O-C-O plane in the last case) and the C-Br bond parallel to one of the C-O bonds. n n n n n3. n nPreferred conformations have been established for the axial isomer of 2-chloromethyl-2,4-dimethyl-1,3-dioxane.

Dipole moments and polarizability anisotropy parameters of several cyclic acetals

1. n nThe orientations of the dipole moments of 1,3-dioxane, 1,3-dioxolane, and their 2-phenyl- and 2-p-nitrophenyl derivatives, as well as the polarities of the C-Ar groups have been determined. n n n n n2. n nThe parameters of the polarizability of the benzylidene and p-nitrobenzylidene groups which have two C-O bonds in the α position have been determined. n n n n n3. n nThe effective conformations of the aryl groups in position 2 in. 1,3-dioxanes and 1,3-dioxolanes, which are characterized by the angles of rotation from the CAr-C-H plane, have been established.

Polarity, anisotropy of the polarizability, and spatial structure of acetals and ketals

1. n nThe dipole moments of the two kinds of C-O bonds in acetals and their analogs are not identical. n n n n n2. n nIn formal molecules and the dimethylketal of acetone the C-O-C-O -C chains have gauche-gauche conformation, with the methyl groups lying on different sides of the O-C-O plane. n n n n n3. n nThe dimethylketal of tetrachlorocyclopentadienone is represented by a mixture of trans-gauche and gauche-gauche conformers.