The Li2CN molecule has been detected by means of Knudsen effusion mass spectrometry. The ionization potential and the energy of dissociation to LiNC and Li, D-0 degrees (LiNC-Li), have been obtained. The measured value of D-0 degrees (LiNC-Li) is 32.7 +/- 3.3 kcal/mol, which indicates strong bonding of lithium to the LiNC fragment. Theoretical calculations indicate a somewhat lower dissociation energy of 24.4 kcal/mol. The favored structure has C-s symmetry and is best described as a "salt" of the Li-2(+) cation with the CN- anion. Another C-s-symmetric structure has a similar stability, while two linear isomers are higher in energy. The presence of a Li-2(+) unit justifies the term hyperlithiated for this system, the first such system with more than one electronegative atom to be characterized thermochemically.