CLUSTERS CONTAINING YNAMINE LIGANDS .5. COORDINATION AND TRANSFORMATIONS OF AN YNAMINE LIGAND IN A DIMANGANESE COMPLEX - SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF MN2(CO)8[MU-MEC2NET2], MN2(CO)8[MU-H2CCC(H)NET2], MN2(CO)8[MU-ETA-2-C3H3NET2], AND MN2(CO)7[MU-ETA-4-C3H3NET2]

The complex Mn2(CO)8(mu-MeC2NEt2) (1), obtained from the photoreaction of Mn2(CO)10 with MeC2NEt2, has been structurally characterized and shown to contain an ynamine ligand asymmetrically bridging the two mutually bonded manganese atoms. The new isomer Mn2(CO)8(mu-H2CCCHNEt2) (2) was isolated in very low yield (0.7%) from this reaction. Compound 2, a second isomer, Mn2(CO)8[mu-eta(2)-C3H3NEt2] (3), and a decarbonylation product of 3, Mn2(CO)7[mu-eta(4)-C3H3NEt2] (4), were obtained in yields of 16%, 8%, and 22%, respectively, by heating 1 to reflux in THF solvent. All three compounds were characterized by crystallographic methods. Compound 2 is the first example of a metal complex containing a aminoallene ligand. This ligand bridges the two metal atoms. Compound 3 contains a bridging eta(2) metalated aminoallyl ligand. Compound 4 contains a bridging eta(4) metalated aminoallyl ligand. Crystal data: for 1, space group P2(1)/c, a = 13.608 (2) angstrom, b = 13.874 (8) angstrom, c = 20.044 (3) angstrom, beta = 92.32 (1)-degrees, Z = 8, 2293 reflections, R = 0.053; for 2, space group P2(1)/n, a = 10.414 (2) angstrom, b = 24.02 (1) angstrom, c = 7.618 (2) angstrom, beta = 107.86 (1)-degrees, Z = 4, 1412 reflections, R = 0.040; for 3, space group P1BAR, a = 10.999 (2) angstrom, b = 12.684 (3) angstrom, c = 7.076 (2) angstrom, alpha = 93.08 (2)-degrees, beta = 107.90 (2)-degrees, gamma = 101.63 (2)-degrees, Z = 2, 1891 reflections, R = 0.022; for 4, space group P2(1)/n, a = 17.904 (2) angstrom, b = 7.509 (2) angstrom, c = 24.555 (4) angstrom, beta = 91.19 (1)-degrees, Z = 8, 2180 reflections, R = 0.031.