Investigations on UV and IR<b> </b>spectra for C₈₀O<i>n</i> (<i>n</i>=1,2)

Abstract

Equilibrium geometries and relative stability of possible isomers for C₈₀O and C₈₀O₂ have been studied using the AM1 method. The most stable geometry for C₈₀O has been found to be 1,2- C₈₀O when the oxygen atom is added to the 6/5 bond. The most stable geometry for C₈₀O₂ is 1, 2,14,15 - C₈₀O₂ with an epoxide structure at the C(1)-C(2) bond . UV-vis and IR

spectra for the isomers of C₈₀O<i>n</i> (<i>n</i>=1,2) have been investigated using the INDO/CIS and AM 1 methods. First absorptions in the electronic spectra and strongest absorptions in the IR spectra arc blue-shifted in the order C₈₀(<i>I_h</i>),1, 2 - C₈₀O and 1, 2,14,15 - C₈₀O₂ as the LUMO-HOMO energy gap increases and the conjugated system gets stabilized. Also, the C-C<i> </i>bonds

are strengthened owing to the addition or the oxygen atoms.