Tomiharu Hosaka

13C NMR spectrum analysis of electrochemically prepared polythienylene films

The 13C NMR spectrum analysis of electrochemically prepared polythienylene films has been investigated. Both a film doped with ClO−4 ions (PT–ClO4) and an undoped film (PT0) through the electrochemical reduction of PT–ClO4 give only two sharp absorption bands. The spectra of PT–ClO4 and PT0 are remarkably similar to each other in shape. These results demonstrate that both polythienylene are well‐defined polymers with only two kinds of carbon atoms which are compatible with dominance of the α–α′ linkage. The upfield shift of the absorption band for PT0 compared with PT–ClO4 is consistent with the increase in electron density through the electrochemical reduction.

13C NMR and Fourier transform infrared study of electrochemically prepared polythienylene film

Abstract The 13 C NMR and Fourier transform infrared (FTIR) spectra of an electrochemically prepared polythienylene film have been obtained. The polythienylene film displays only two sharp absorption bands, at 124.8 and 136.5 ppm downfield from TMS (tetramethylsilane) in the 13 C NMR, these being attributable to the carbon atoms in the β-position and the α-position, respectively, relative to the sulfur atom of poly(2,5-thienylene). The polythienylene film also shows a sharp absorption band at 789 cm −1 in the IR, which is definitely ascribable to the C-H out-of-plane vibration of poly(2,5-thienylene). The polythienylene film will be shown to have a highly defined structure with a dominance of poly(2,5-thienylene).

Electrochemically prepared poly(3-methylthienylene) films doped with iodine

Abstract Electrochemically prepared poly(3-methylthienylene) films doped with iodine have been investigated and the relationship between their conductivity and iodine content was studied. The conductivity of the films with various iodine contents was obtained in accordance with an Arrhenius equation with an activation energy equal to 0.17 to 0.033 eV. The highest conductivity was 5 S cm−1. The activation energy, which is dependent on the iodine content, shows discontinuous change, as is the case with polyacetylene doped with iodine. The relationship between conductivity and structure of the poly(3-methylthienylene) films will be discussed.

13C NMR spectrum analysis of electrochemically prepared poly(3-methylthienylene) films

Abstract The 13 C NMR spectrum analysis of electrochemically prepared poly(3-methylthienylene) films has been investigated. Both a film doped with ClO 4 ions (P3MT-ClO 4 ) and an undoped film (P3MT 0 ) give only two distinct absorption bands through the electrochemical reduction of P3MT-ClO 4 . These distinct bands are definitely attributable to the methyl group (upper field) and the thiophene ring (lower field), respectively, and are characteristic of well-defined poly(3-methylthienylene). The correlation between conductivity and 13 C NMR spectra will be discussed.

Performance of a high-density optical recording disk using vacuum-evaporation-deposited organic dye film

High density optical recording disk using vacuum evaporation deposited organic dye film is newly developed. As we investigate the signal characteristics of the vacuum evaporated disk in comparison with the disk fabricated by conventional spin-coat method, it is found that the vacuum evaporated disk has some features: to keep uniformity of tracking signal easily, high modulation, and wide power margin. Furthermore, it is clarified that the recording mechanism of the evaporated disk includes the hole formation by sublimation of the dye material. We confirm that the performance of the vacuum evaporated disk is high potentiality for DVD-R.