Synthesis and characterisation of nitrile complexes of iron

Article abstract of DOI:10.1016/S0022-328X(96)06912-4

The reaction of cis-[FeH₂(DMPE)₂] (DMPE = 1,2-bis(dimethylphosphino)ethane) (1a) and trans-[FeCl₂(DMPE)₂] (7a) with acetonitrile, cyanocyclopropane, benzonitrile, p-bromobenzonitrile and terephthalonitrile and reaction of trans-[FeCl₂(DEPE)₂] (DEPE = 1,2-bis(diethylphosphino)ethane) (7b) with acetonitrile, cyanocyclopropane and benzonitrile in methanol solution resulted in a series of nitrile chloride complexes trans-[FeCl(N≡C-R)(PP)₂]⁺ and bis-nitrile complexes trans-[Fe(N≡C-R)₂(PP)₂]²⁺ of iron. All of the complexes have been characterised spectroscopically and four bis-nitrile complexes have been characterised crystallographically. Crystals of trans-[Fe(N≡CCH₃)₂(DMPE)₂][2PF₆] (3a) are monoclinic, space group P2/c, with a = 8.697(3), b = 9.165(5), c = 20.026(5)A, β = 107.54(3)°, Z = 2 and R = 0.058 (2300 F values). Crystals of trans-[Fe(N≡CC₃H₅)₂(DEPE)₂][2BF₄] (4b) are monoclinic, space group P2₁/n, with a = 11.146(1), b = 15.396(2), c = 11.810(2)A, β= 111.06(1)°, Z = 2 and R = 0.050 (3011 F values). Crystals of trans-[Fe(N≡CPh)₂(DMPE)₂][2PF₆] (5a) are monoclinic, space group P2₁/n, with a = 11.006(2), b = 12.351(3), c = 13.650(4)A, β = 93.60(2)°, Z = 2 and R = 0.035 (2650 F values). Crystals of trans-[Fe(p-N≡CC₆H₄Br)₂(DMPE)₂][2PF₆][0.5KPF₆] (6a) are tetragonal, space group 14c2, with a = b = 20.015(6), c = 21.610(3) A, β = 90.00°, Z = 8 and R = 0.049 (2235 F values).