isomeric (adj.) Look up isomeric at Dictionary.com
"pertaining to or characterized by isomerism," 1831, from German isomerisch (Berzelius, 1831, in a paper on the "Composition of the Tartaric and Paratartaric Racemic Acids"), from Greek isomeres "sharing equality, having equal parts or shares," from iso- "equal" (see iso-) + meros "part, share" (see merit (n.)). Isomerous is from 1845 in botany, 1840 in chemistry.