Norihito Sogoshi

Synthesis and Hole Transport Properties of Highly Soluble Pyrene-Based Discotic Liquid Crystals with Trialkylsilylethynyl Groups

Four pyrene-based discotic compounds with trialkylsilylethynyl groups in the side chains were prepared and characterized by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction measurements. All of the compounds were highly soluble in organic solvents, and two of the compounds exhibited a columnar phase, Colr, and the others were crystalline. The hole transport ability in the liquid-crystalline phases was determined by the time-of-flight (TOF) method to be on the order of 10−2 cm2 V−1 s−1, the highest hole mobilities for pyrene derivatives yet observed.

Synthesis of Amorphous Germane by Tunneling Reactions of Hydrogen Atoms with van der Waals GeH4 Films at Cryogenic Temperatures

The reactions of hydrogen atoms with a thin GeH4 film condensed on a substrate at 10 K led to the formation of amorphous-like solid film. The solid products were analyzed by in-situ Fourier transform-infrared spectroscopy, ex-situ spectroscopic ellipsometry, and X-ray photoelectron spectroscopy. It was found that the solid products were mainly composed of hydrogenated amorphous germane and polygermanes. It was proposed that the singlet GeH2 which is the intermediate product in the consecutive reactions of H with GeH4 inserts into the neighboring Ge–H bonds resulting in the Ge–Ge bond network. It was found that up to the equivalent ~23 GeH4 monolayers from the top surface of the reactant GeH4 film were converted to the solid product but not deeper.

REFRACTIVE INDICES OF WATER AND AQUEOUS ELECTROLYTE SOLUTIONS UNDER HIGH MAGNETIC FIELDS

The refractive index of water was measured at atmospheric pressure under magnetic fields up to 10 T and found to increase by ∼0.1% with increasing magnetic field strength. In contrast, the refractive index of saturated aqueous electrolyte solutions decreased under the magnetic field. In the case of n-hexane, any change of the optical property by the magnetic field was not found. A possible explanation is that the lifetime of the hydrogen bond is prolonged due to the electron delocalization of a water dimer under the magnetic field.