The ground state of antiaromatic 1,3,5,7-tetra-tert-butyl-s-indacene

Abstract

The electronic and vibrational properties of the antiaromatic molecule 1,3,5,7-tetra-tert-butyl-s-indacene (TTBI) in the ground state are investigated in this paper. MO ab initio calculations have been performed on TTBI and the parent molecule, s-indacene (I). The results show that the C-C bonds of s-indacene alternate in length and the corresponding C 2h structure is more stable than the structure without bond alternation (D 2h symmetry), regardless of the basis set used. Bond length alternation is decreased by alkyl substitution in the 1, 3, 5, and 7 positions