CHARACTERIZATION OF HYDROGENATED DERIVATIVES OF METHYLDICYCLOPENTADIENE AND DIMETHYLDICYCLOPENTADIENE ISOMERS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY AND C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

The identification of the di- and tetrahydrogenated derivatives of met hyl- and dimethyldicyclopentadiene isomers has been performed directly in the hydrogenated mixtures, by comparing the results from the gas c hromatography-mass spectrometric mass balance with those from quantita tive C-13 nuclear magnetic resonance spectra. The assignment of the ca rbons of these isomers has been realized by analysing data from J-modu lated spin-echo sequences and by applying semi-empirical rules for the influence of the methyl groups on the carbon chemical shifts in cyclo pentane and norbornane ring systems.