C10H8N2

from The Collaborative International Dictionary of English v.0.48

Dipyridyl \Di*pyr"i*dyl\, n. [Pref. di- + pyridine + -yl.]
   (Chem.)
   A crystalline nitrogenous base, {C10H8N2}, obtained by the
   reduction of pyridine.
   [1913 Webster]