1 SC0 (6e,11e)-heptadeca-6,11-diene-9,9-diylbis(phosphonic acid) 1.000 2 749 [(6e,11e)-2,6,12,16-tetramethylheptadeca-2,6,11,15-tetraene-9,9-diyl]bis(phosphonic acid) 0.862