Junko Yoshino

Polarized Absorption Spectra of 1,10-Phenanthroline and Phenanthrene in Stretched PVA Sheets

The divided spectra of 1,10-phenanthroline and phenanthrene were obtained, and the polarization direction of each band in the near ultraviolet region was determined. By comparison of the results of the divided spectra and those of the Pariser-Parr-Pople calculations including a variable ß approximation, assignment of the electronic bands of these compounds was established. It has been found that 1,10-phenanthroline has the a;-polarized bands (polarized perpendicularly to the (72-axis) at 30.7 kK, 34.5 kK, 37.3 kK and 43.7 kK, and the 2/-polarized bands (parallel to the C2-axis) at 29.4 kK, 39.2 kK and 42.7 kK. The a;-polarized band at 30.7 kK might be assigned to be due to an

Electronic Spectra of Phenolate and Naphtholate Anions

The transition energies, oscillator strengths and polarization directions of phenolate, ocand ^-naphtholate ions were calculated by use of the PPP procedure including a variable electronegativity (VESCF) and variable ß methods. As for the naphtholate ions, the calculated results were compared with the results of the polarized aborption spectra using stretched PVA (polyvinyl alcohol) sheets. The calculated results are in good agreement with the experimental data including polarization directions. In the semiempirical calculations, the second ionization potential of the 0~ ion was approximated by In--+o+

Polarized Triplet-Triplet Absorption Spectra Using Stretched Polymer Films: Biphenyl and Fluorene

Polarized triplet-triplet (Tn-t-Ti) absorption spectra of biphenyl and fluorene were measured in stretched polymer (polyvinylalcohol) films, and the polarizations of the Tn^-Ti transitions were determined. It has been clarified that the Tn <Ti band of fluorene in the wave number region of 24—30 kK consists of two different electronic transitions polarized perpendicularly to each other, i. e. the longer molecular-axis polarized band system (the 0—0 band

POLARIZED TRIPLET–TRIPLET ABSORPTION SPECTRUM USING STRETCHED POLYMER FILM AT LIQUID NITROGEN TEMPERATURE: DIPHENYLACETYLENE

Measurements of a polarized triplet–triplet absorption spectrum using stretched polymer films have been attempted at liquid nitrogen temperature. The polarizations of the triplet–triplet transitions of diphenylacetylene were determined, and the molecular structure in the excited triplet state was discussed.