Application of lanthanide induced shifts in proton magnetic resonance spectroscopy of juvenile hormones.
A downfield shift of proton signals up to 9 ppm is induced in the 1H NMR spectra of juvenile hormone I (methyl 3,11-dimethyl-10,11-cis-epoxy-7-ethyl-2-trans, 6-trans-tridecadienoate) and III (methyl 10,11-epoxy-2-trans, 6-trans-farnesoate) by the lanthanide complex Eu(fod)3. A plot of induced shift vs the ratio of [LSR]/[substrate] shows a good linear correlation for the range 0.3--1.0 mole ratio. Highest shifts are induced for the protons H-10 and H-2 adjacent to the two Lewis base groups of the hormone. Resolution due to induced shift decreases for the other signals with increasing distance of protons from the two coordination sites.
D005063:Europium; D005583:Fourier Analysis; D007605:Juvenile Hormones; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation
D007605:Juvenile Hormones; D005063:Europium