Theoretical analysis of the oxocarbons: The role played by the solvent and counter-ions in the electronic spectrum of the deltate ion

Abstract

The structure and spectroscopic properties of the deltate anion are calculated in the gas phase using ab initio quantum chemical methods and in aqueous solution through a sequential Monte Carlo-quantum mechanical procedure. The effects of the solvent and counter-ions on the electronic spectrum are analyzed, showing that both should be included in the calculation in order to reproduce the observed UV spectrum. For the smallest cyclic oxocarbon, the deltate anion, the calculated electronic transitions were 254 and 246 nm considering the [Li₂(C₃O₃)(H₂O)₂₀] species. This is in accordance with the expected behavior for the oxocarbon series, predicting absorption bands close to 200 nm for the deltate anion.