SYNTHESIS AND CHARACTERIZATION OF NITRILE COMPLEXES OF IRON

The reaction of cis-[FeH2(DMPE)(2)] (DMPE = 1,2-bis(dimethylphosphino) ethane) (la) and trans-[FeCl2(DMPE)(2)] (7a) with acetornitrile, cyano cyclopropane. benzonitrile p-bromobenzonitrile and terephthalonitrile and reaction of trans-[FeCl2(DEPE)(2)] (DEPE = 1,2-bis(diethylphosphin o)ethane) (7b) with acetonitrile, cyanocyclopropane and benzonitrile i n 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 characteris ed spectroscopically and four bis-nitrile complexes have been characte rised crystallographically. Crystals of trans-[Fe(N=CCH3)(2)(DMPE)(2)] [2PF(6)] (3a) are monoclinic, space group P 2/c, with a = 8.697(3), b = 9.165(5), c = 20.026(5) Angstrom, beta = 107.54(3)degrees, Z = 2 and R = 0.058 (2300 F values). Crystals of trans-[Fe(N=CC3H5)(2)(DEPE)(2) ][2BF(4)] (4b) are monoclinic, space group P2(1)/n, with a = 11.146(1) , b = 15.396(2), c = 11.810(2) Angstrom, beta = 111.06(1)degrees, Z = 2 and R = 0.050 (3011 F values). Crystals of trans-[Fe(N=CPh)(2)(DMPE) (2)][2PF(6)] (5a) are monoclinic, space group P2(1)/n, with a = 11.006 (2), b = 12.351(3), c = 13.650(4) Angstrom, beta = 93.60(2)degrees, Z = 2 and R = 0.035 (2650 F values). Crystals of s-[Fe(p-N=CC6H4Br)(2)(D MPE)(2)][2PF(6)][0.5KPF(6)] (6a) are tetragonal, space group <I(4)over bar c2>, with a = b = 20.015(6), c = 21.610(3)Angstrom, beta = 90.00 degrees, Z = 8 and R = 0.049 (2235 F values).