Negative ion photoelectron spectroscopy confirms the prediction that D_3h carbon trioxide (CO₃) has a singlet ground state.

ABSTRACT: The CO₃ radical anion (CO₃˙^-) has been formed by electrospraying carbonate dianion (CO₃^2-) into the gas phase. The negative ion photoelectron (NIPE) spectrum of CO₃˙^- shows that, unlike the isoelectronic trimethylenemethane [C(CH₂)₃], D_3h carbon trioxide (CO₃) has a singlet ground state. From the NIPE spectrum, the electron affinity of D_3h singlet CO₃ was, for the first time, directly determined to be EA = 4.06 ± 0.03 eV, and the energy difference between the D_3h singlet and the lowest triplet was measured as ΔE_ST = - 17.8 ± 0.9 kcal mol^-1. B3LYP, CCSD(T), and CASPT2 calculations all find

SUBMITTER: Hrovat DA 

PROVIDER: S-EPMC5975725 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature