Sr[C2O5] is an Inorganic Pyrocarbonate Salt with [C2O5]2- Complex Anions

The synthesis of a novel type of carbonate, namely of the inorganic pyrocarbonate salt Sr[C2O5], which contains isolated [C2O5](2-)-groups, significantly extends the crystal chemistry of inorganic carbonates beyond the established sp(2)- and sp(3)- carbonates. We synthesized Sr[C2O5] in a laser-heated diamond anvil cell by reacting Sr[CO3] with CO2. By single crystal synchrotron diffraction, Raman spectroscopy, and density functional theory (DFT) calculations, we show that it is a pyrocarbonate salt. Sr[C2O5] is the first member of a novel family of inorganic carbonates. We predict, based on DFT calculations, that further inorganic pyrocarbonates can be obtained and that these will be relevant to geoscience and may provide a better understanding of reactions converting CO2 into useful inorganic compounds.

Automated summary

Researchers have synthesized a novel inorganic pyrocarbonate salt, Sr[C2O5], which contains isolated [C2O5](2-) groups. This discovery significantly expands the crystal chemistry of inorganic carbonates. Through experimental and theoretical calculations, it is shown that Sr[C2O5] is a pyrocarbonate salt and it is predicted that more inorganic pyrocarbonates can be obtained. These findings are relevant to geoscience and provide insights into the conversion of CO2 into useful inorganic compounds.