Carbonylation of iron(II) halide in the presence of chelate diphosphine ligands. Molecular structure of a novel intermolecular adduct

Article abstract of DOI:10.1016/0022-328X(95)06061-Z

Treatment of tetrahydrofuran solution of FeCl2*4H2O or FeX2 (X=Br, I) and chelate diphosphines L₂ 2=ⁱBuN(PPh2)2, ⁱPrN(PPh2)2, Ph2PCH2CH2PPh2 (dppe)> with carbon monoxide at room temperature and atmospheric pressure gives trans-Fe(CO)2X2L2 (X=Cl, Br, I) in high yields.Their IR, 31PNMR spectra and X-ray crystallography prove that they have the structures of trans-carbonyls and cis-halogens.Reaction of FeCl2*4H2O and dppe with carbon monoxide gives a novel cage intermolecular adduct in wich the active species of Fe2(CO)2Cl4 is stabilized by the cage structure of FeCl2(dppe)₂ in crystalline state.The structures of Fe(CO)2I2<ⁱBuN(PPh2)2> (1) and (8) are determined by X-ray crystallography.Compound 1 crystallizes in space group P1', with a=9.605(2), b=10.295(2), c=17.219(4) Angstroem, α=97.86, β=94.98(2), γ=109.16(2) deg, and Z=2, R=0.071, Rw=0.080.Compound 8 crystallizes in the space group P1', with a=9.874(2), b=10.576(1), c=13.347(4) Angstroem, α=86.09(2), β=85.05(2), γ=81.43(1) deg, and Z=1, R=0.078, Rw=0.082. - Keywords: Carbonylation; Adducts; Iron halides