Electrical conductivity, DSC, XRD, and 7Li NMR studies of rotator crystals n-C21H43COOLi x K(1 − x) (0.33 ≤ x ≤ 0.50), n-C m H(2m + 1)COOLi, and n-C m H(2m + 1)COOK (m = 13, 15, 17, 19, and 21)

Differential scanning calorimetry (DSC) thermograms, X-ray diffraction (XRD) analysis, electrical conductivity (σ), and ⁷Li NMR spectroscopy characterization of n-C _m H_(2m?+?1)COOM solids (M = Li, Na, K; m?=?13, 15, 17, 19, 21) and mixed crystals n-C₂₁H₄₃COOLi _x K_(1???x) (0.25?≤?x?≤?0.75) was performed as a function of temperature. DSC thermograms of n-C _m H_(2m?+?1)COOM revealed several solid-solid phase transitions with large entropy changes. Electrical conductivity studies established that n-C _m H_(2m?+?1)COOLi crystals are poor electrical conductors. In contrast, n-C _m H_(2m?+?1)COOK salts were found to have σ values of 10^???7–10^???8 S·cm^???1. Since the crystal structures and phase-transition temperatures of both n-C _m H_(2m?+?1)COOLi and n-C _m H_(2m?+?1)COOK crystals were similar, they were able to form mixed crystals with the structure n-C _x H_(2m?+?1)COOLi _x K_(1???x). DSC thermograms of the mixed crystals showed a small entropy change at the melting point (ΔS _mp?<?13 J K^???1 mol^???1), in addition, large ΔS values at the solid-solid phase transition temperature. The σ values obtained for mixed crystals were roughly one order of magnitude greater than those determined for n-C₂₁H₄₃COOK crystals. ⁷Li NMR spectra of the mixed crystals recorded at various temperatures suggested that the self-diffusion of Li^?+? ions was excited in the highest-temperature solid phase. Based on these results, we have classified these mixed crystals as rotator crystals.     

Zur Charakteristik der Entladungen von elektrostatisch aufgeladenen Geweben

Ohne Zusammenfassung     

Torsional bands of hydroxylamine

Infrared absorption spectrum of NH₂OH has been observed in its gaseous state, and the fine structures of the bands at 386 and 751 cm^?1 assignable, respectively, to the fundamental and overtone of the torsional vibration of this molecule have been examined. Band center frequencies for the n = 1 ← 0, 2 ← 1, 3 ← 2, 2 ← 0, and 3 ← 1 transitions (where n is the vibrational quantum number of the torsional oscillation) have been determined to be 386.2, 365.1, 346.3, 751.2, and 711.3 cm^?1, respectively. On the basis of these data, a discussion is given on the internal-rotation potential function.