Alpha-olefin are manufactured in high yield and with very high selectivity
by contacting ethylene with an iron complex of a selected
2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridine
bisimine, and in some cases a selected activator compound such as an
alkyl aluminum compound. Novel bisimines and their iron complexes are
also disclosed. The .alpha.-olefin are useful as monomers and chemical
intermediates.