A computational study of two promising tweezers

Abstract

A DFT study was carried out to explore the properties of two nonplanar π-conjugated systems that share dibenzo[a,e]-cyclooctatetraene (DBCOT) as a fundamental element. These systems were presented as molecules with potential use as tweezers and in optoelectronic applications due to their expected nonlinear optical effects. Structure optimizations, TD-DFT calculations, molecular orbitals and topological analysis were performed for C36N2H18O4 and C26H18 structures, formed by one and two 1,3,5,7-cyclooctatetraene rings, respectively, with and without the Na cation. This alkali cation was used as a model to investigate the potential of these molecules as tweezers. The results show a V-shaped structure as a minimum in the ground state for both molecules. This angular structure can trap the Na cation very effectively, especially for one of the cases. In addition, the present analysis opens new studies to explore the use of these systems as tweezers of other cations, anions or aromatic molecules that may exhibit π-stacking. The analysis of the molecular orbitals involved in the main electronic transitions allows us to propose that these systems will have interesting optical properties.