Carbon tetroxide
Carbon tetroxide is a highly unstable oxide of carbon with formula. It was proposed as an intermediate in the O-atom exchange between carbon dioxide and oxygen at high temperatures. The C2v isomer, which is -138 kJ mol−1 more stable than the D2d isomer, was first detected in electron-irradiated ices of carbon dioxide via infrared spectroscopy.
The isovalent carbon tetrasulfide is also known from inert gas matrix. It has D2d symmetry with the same atomic arrangement as CO4.
