TY - JOUR KW - carbon dioxide KW - carbonate KW - CO2 reduction catalysis KW - C-O activation KW - formate KW - oxalate AU - Leah Dodson AU - Michael Thompson AU - J. Mathias Weber AB - Redox chemistry during the activation of carbon dioxide involves changing the charge state in a CO2 molecular unit. However, such changes are usually not well described by integer formal charges, and one can think of COO functional units as being in intermediate oxidation states. In this article, we discuss the properties of CO2 and CO2-based functional units in various charge states. Besides covering isolated CO2 and its ions, we describe the CO2-based ionic species formate, oxalate, and carbonate. Finally, we provide an overview of CO2-based functional groups and ligands in clusters and metal–organic complexes. BT - Annual Review of Physical Chemistry DA - 2018-02 DO - 10.1146/annurev-physchem-050317-021122 N2 - Redox chemistry during the activation of carbon dioxide involves changing the charge state in a CO2 molecular unit. However, such changes are usually not well described by integer formal charges, and one can think of COO functional units as being in intermediate oxidation states. In this article, we discuss the properties of CO2 and CO2-based functional units in various charge states. Besides covering isolated CO2 and its ions, we describe the CO2-based ionic species formate, oxalate, and carbonate. Finally, we provide an overview of CO2-based functional groups and ligands in clusters and metal–organic complexes. PY - 2018 T2 - Annual Review of Physical Chemistry TI - Characterization of Intermediate Oxidation States in CO2 Activation UR - https://www.annualreviews.org/doi/10.1146/annurev-physchem-050317-021122 VL - 69 SN - 0066-426X ER -