Definition: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
gadoversetamide [ Mallinckrodt brand of gadoversetamide,OptiMARK,Tyco brand of gadoversetamide ] nonionic, linear chelate used for magnetic resonance imaging of brain and spine