Syntheses of NN′-ethylenebis(salicylideneiminate) transition-metal chelates by oxidative decarbonylation

Abstract

Reaction of NN′-ethylenebis(salicylideneiminato)mercury(II), [Hg(salen)], with certain transition-metal carbonyls leads to the formation of the corresponding chelate of the transition-metal ion with deposition of mercury or the formation of mixed-metal chelates. Thus [Cr(CO)₆] and [Mo(CO)₆] give [Cr(salen)]₂O and [MoO-(salen)]₂O respectively. The compound [{Fe(cp)(CO)₂}₂](cp =η-cyclopentadienyl) gives Hg(salen)·Fe(cp)-(salen) which on treatment with glacial acetic acid yields [Fe(salen)]O₂CMe. Dicobalt octacarbonyl gives Hg(salen)·Co(CO)₃ which when heated in pyridine or dimethylformamide yields [Co(salen)] with deposition of mercury.