dianions

https://doi.org/10.1351/goldbook.D01674
Molecular entities bearing two negative charges, which may be located on a single atom or on different atoms or may be delocalized.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1331 [Terms] [Paper]