Showing papers by "Romanian Academy published in 1968"

Hückel Molecular Orbital Models for Heterocycles with Tetra-coordinated Phosphorus Atoms

Abstract: MANY heterocyclic compounds with tetra-coordinated phosphorus atoms have been synthesized1,2. Several models for Hukel molecular orbital calculations3–6 have been proposed for heterocycles containing atoms with d-orbitals, but the most suitable model should first be found before such calculations are made for these phosphorus heterocycles. The most suitable model can be found by comparing the experimental data for phosphabenzene (more exactly 1,1-diphenylphosphabenzene)1,7,8 with the Hukel parameters calculated for all these models.

On the L-Bands and the First Exciton Bands in the Photoemission Spectra of Alkali Iodides

Abstract: The photoemission spectra of NaI, KI, RbI and CsI are investigated experimentally. Besides the bands already revealed by optical absorption measurements and confirmed by photoemission studies, the L1–L4-bands in Nal, the L4-band in RbI, and the fine structure of the E1-bands in KI and RbI are observed. In CsI electron emission is detected corresponding to the first exciton band in the absence of F-centres. The very intense “extra”-bands occurring in the absorption spectra are not found.