Investigations by 13C NMR spectroscopy of ethene-initiated catalytic CO hydrogenation

13C NMR spectroscopy shows that the n-alkene and n-alkane products from the catalytic hydrogenation of CO in the presence of 13C2H4 probes over Ru/150 °C, Co/180 °C, Fe/220 °C, or Rh/190 °C (1 atm, CO:H2 1:1, “mild conditions”) contain terminal 13CH313CH2− units. This is consistent with their formation by a regiospecific polymerization of C1 species derived from CO and initiated by 13C2H4. Although the activities toward individual products differed somewhat, similar distributions and similar product labeling patterns were obtained over all the four catalysts. 1-Butene and the higher 1-n-alkenes from all the catalysts were largely 13CH313CH2(CH2)nCHCH2 (n = 0−3), propene formed over Ru or Co was 13CH313CHCH2, while both 13CH313CHCH2 and 13CH213CHCH3 were formed over Fe or Rh. Comparison of the conclusions from these probe experiments with those from isotope transient experiments by other workers indicates that the ethene initiator does not significantly modify the course of the CO hydrogenation. The reacti...