SOME PROPERTIES OF CYCLACENES AND SILACYCLACENES

Various Huckel type cyclacenes and silacyclacenes are subject to semi- empirical molecular orbital treatment at the level of AMI type. Cyclac enes having silicon atom at the peri and fusion points of arenoid ring s as well as all-silated cyclacenes are considered. The cryptoannuleni c effects, frontier molecular orbital energies, geometries and polariz abilities of these structures have been examined.