Synthesis and Characterization of the Metalloplumbylenes (η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(CO)<sub>3</sub>M-P̈b-C<sub>6</sub>H<sub>3</sub>-2,6-Trip<sub>2</sub> (M = Cr, Mo, or W; Trip = −C<sub>6</sub>H<sub>2</sub>-2,4,6-i-Pr<sub>3</sub>)
作者:Lihung Pu、Philip P. Power、Imke Boltes、Regine Herbst-Irmer
DOI:10.1021/om990774s
日期:2000.2.1
The reaction of Pb(Br)C6H3-2,6-Trip(2) (Trip = C6H2-2,4,6-i-Pr-3), generated in situ, with the salts Na[M(eta(5)-C5H5)(CO)(3)]. DME (M = Cr, Mo, or W; DME = 1,2-dimethoxyethane) affords the novel green, crystalline metalloplumbylenes (eta(5)-C5H5)(CO)(3)M-Pb-C6H3-2,6 -Trip(2) (M = Cr, 1; Mo, 2; W, 3) in moderate yield. The compounds were characterized spectroscopically (H-1, C-13, and Pb-207 NMR, IR, and UV-vis) and by combustion analysis. In addition the X-ray crystal structures of 1-3 were determined. The compounds feature strongly bent geometries at lead (M-Pb-C = 108.6(2)-113.58(9)degrees) and relatively long M-Pb distances (2.9092(9) Angstrom, Cr; 2.9845(7) Angstrom, Mo; 2.9809(10) Angstrom, 3.0055(6) Angstrom W), which are consistent with single M-Pb bonding. The stability of the complexes, which melt with decomposition in the range 210-226 degrees C, is attributed to steric protection of the metal centers by the very large -C6H3-2,6-Trip(2) substituent. The compounds are the first examples of metalloplumbylenes that feature a bent two-coordinate lead geometry.