Abstract
Results from a theoretical study on hexaethynylbenzene (HEB) by MNDO and ab initio (STO-3G) molecular orbital methods are reported. The calculated geometry is in good agreement with the X-ray structure of the hexa-silylated derivative. The molecule HEB has a calculated ionization potential of 8.6 eV for a degenerate orbital. High thermal stability of HEB, is predicted because of the two dimensional aromaticity. STO-3G, 3-21G and 6-31G optimized geometries of
o-diethynylbenzene (DEB) are reported. The 6-31G geometry shows little change from the experimental structure of phenylacetylene indicating small effect of the acetylenic groups on the structure of the benzene ring.