Electronic spectroscopy of some small anions containing S, N and O using CR-EOM-CCSD(T) method

Abstract

The electronic spectroscopy of four anions (SSNSS–, SSNS–, SSNO–, SNO–) was studied using Time-Dependent Density Functional Theory (TD-DFT), Equation Of Motion Coupled Cluster with Singles and Doubles (EOM-CCSD) and the Completely Renormalised Equation-Of- Motion with Singles, Doubles and non-iterative Triples (CR-EOM-CCSD(T)) methods. The same methodology was applied to check the electronic spectroscopy of different anions whose structure or even existence are not well stated (SNS–, SSN–, SSNSO–, ). The agreement of the calculated bands in UV-vis for these compounds with the experimental bands of UV-vis for SSN– and SSNSO– makes it very likely that these molecules were the intermediate ones that absorb strongly in the UV-vis. On the contrary, the fact that was an anion that absorbs strongly in the visible spectrum in certain reactions looks doubtful.