708. Physical properties and chemical constitution. Part XXVII. Dipole moments of some cyclic ethers, sulphides, sulphoxides, and sulphones

Abstract

The orientation polarisations and dipole moments of four cyclic organic sulphides , and the related sulphoxides and sulphones, have been calculated from measurements of the dielectric constants, specific volumes, and refractive indices of their solutions in benzene. The dipole moments are discussed in terms of the moment of the sulphur-oxygen link and the geometrical structure of the molecules. The dipole moments of five cyclic ethers have also been measured, and the carbon-oxygen bond moment evaluated and compared with that of non-cyclic ethers.THE electric dipole moments of several organic sulphides, sulphoxides, and sulphones are recorded in the literature but only in four cases have the moments of the sulphide and the corresponding sulphoxide and sulphone been measured. No cyclic sulphoxides or sulphones have been investigated.

Nuclear magnetic resonance spectra of the epihalohydrins: II. Spectral analyses and structural correlations for all the epihalohydrins

“…The dipole moment of propylene oxide found in this study is in good agreement (Table 5) with previously reported values (16,17,21). The decreasing preponderance of polar conformers with increasing size of halogen is obvious from the trend in the series.…”

“…At least in the case of propylene oxide (P,V"Ccl = 15.92, P,cxpL = 15.67, 16.21 (16,17)), this approxinlation ]nay be shown to lead to no significant error. Molar atom polar~zat~ons (PA) were assigned at the reasonable value of (0.1 x P,), following the i~sual practice (10).…”

Anionic polymerization of styrene in oxepane (hexamethylene oxide)•counter-ion, sodium

“…1.55 D (19), pOXp = 1.51 D)3 although there seems to be a downward trend with increasing ring size. Ion-dipole interaction of solvent molecules with the cation will, therefore, be similar in all three cases although again slightly stronger with THF.…”

The conformational preference and barrier to internal rotation of an equatorial 3,5-dichlorophenyl group by the J method. Derivatives of cyclohexane, 1,3-dithiane, 1,3-dioxane, and 1,3-dioxolane

“…In previous work (30), we have argued that highly electronegative substituents at the ci carbon atom appreciably reduce 'J,,, TWO In the gas phase, 1,3-dioxolane is almost a free pseudorotor (31), whereas in solution the envelope form is apparently rather more stable (5,32,33). Detailed equilibration (34) and 13C chemical shift (35) studies of various 1,3-dioxolane derivatives suggest to us that there exists very little preferred equatorial or axial character in 9, the ring being highly flexible.…”