(Chem.) Either of two metameric nitrogenous hydrocarbon bases, C12H8N2, analogous to phenanthridine, but more highly nitrogenized.
phenanthroline
phenanthroline
[fə′nan·thrə‚lēn] (organic chemistry) C12H8N2 Any of three nitrogen bases related to phenanthrene; the ortho form is an oxidation-reduction indicator, turning faint blue when oxidized.