Atranes. II. Dipole moments and structure of silatranes

Possible steric configurations of 1-organyl- and 1-organoxysilatranes,, are considered. The dipole moments of six compounds of this type (X=CH₃, (CH₃)₂CH, CH₂=CH, C₆H₅, C₂H₅O, C₆H₅O) have been found experimentally to be extremely high, 5.3–7.1 D. They conclusively show that the silatranes contain a semipolar transannular coordinate bond SiN between the negatively charged 5 -covalent silicon atom in the middle of the planar SiO₃ group and the tetrahederal onium nitrogen atom.Part I, see [1].     

Stereochemistry of eight-membered heterocycles. 4. Dipole moments of cyclic acetals with two planar fragments

An additive system of polarities in 12H-dibenzo(dinaphtho)[d,g][1,3]dioxocins is proposed, and alkyl—oxygen and phenyl—oxygen group dipole moments in these compounds were determined. The stereospecific relation of the polarity of the C _sp 2-O bond to the mutual orientation of p orbitals of unshared electron pairs of oxygen atoms and orbitals of the aromatic ring is shown.A. N. Butlerov Scientific-Research Chemical Institute, V. I. Ul'yanov-Lenin Kazan State University, Kazan 420008. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 607–612, March, 1992.     

Dipole moments and spatial structure of some trisarylselenomethanes

Conclusions Trisarylselenomethanes exist in a conformation with a gauche orientation of the three Ar-Se groups relative to the C-H bond of the central atom.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 436–438, February, 1977.     

Dipole moments and structure of poly(epoxypropylcarbazole)

The mean-square molecular dipole moments 〈μ²〉 of carbazole, N-ethylcarbazole and of the sequence of poly(epoxypropylcarbazole) (PEPCa) oligomers of various molecular weights have been evaluated in solutions of these organic compounds in dioxan. For PEPCa the values of 〈μ²〉 have also been determined in the solid state. On the basis of the experimental results and of molecular mechanics calculations it has been shown that the orientation of the lateral group of PEPCa favors noninteracting racemic dyads. The temperature-dependence of the effective dipole moment of solid PEPCa follows the Onsager theory above 295 K.