Geminal

Two substituents are said to be geminal if they are both attached to the same carbon. 2,2-dibromopropane is an example of a geminal dihalide. Sometimes abbreviated gem– .  A hydrate is a gem-diol. Distinct from vicinal, which indicates substitution on adjacent carbons.  (From the Latin gemini for twins).

[class^="wpforms-"]
[class^="wpforms-"]