Inorganic Chemistry, Vol.35, No.6, 1535-1539, 1996
Coordinatively and Electronically Unsaturated Tungsten(0) Carbonyl-Complexes Stabilized by Pi-Donating Amido Ligands
Novel, coordinatively and electronically unsaturated tungsten tricarbonyl dianions of 2-aminophenol and 1,2-diaminobenzene have been synthesized from the reaction of photogenerated W(CO)(5)THF and [Et(4)N][OC6H4NH2] with subsequent deprotonation by [Et(4)][OH] accompanied by facile CO dissociation, and the reaction of W(CO)(5)THF and 2 equiv of [Et(4)N][NHC6H4NH2], respectively. These air-sensitive derivatives have been fully characterized both in solution (nu(CO) and C-13 NMR) and in the solid-state (X-ray crystallography). These metal dianions which have formally 16e(-) configurations are stabilized by pi-donation from the amido groups of the chelating ligands, as evident from short W-N bond distances. Both solution (nu(CO) and C-13 NMR) and solid-state (W-N vs W-O bond distances) data on these derivatives indicate the amido ligand to be a better ct-donor than the oxo ligand. Complex 2 crystallized in the monoclinic space group P2(1)/n with a 14.499(5) Angstrom, b = 14.708(5) Angstrom, c = 15.137(4) Angstrom, beta = 114.13(2)degrees, V = 2946(2) Angstrom(3), and d(calc) = 1.433 g/cm(3), for Z = 4. Complex 3 crystallized in the triclinic space group
with a = 11.479(6) Angstrom, b = 11.786(8) Angstrom, c = 13.148(7) Angstrom, alpha = 102.41(5)degrees, beta = 91.27(4)degrees, gamma = 99.96(5)degrees, V = 1708(2) Angstrom(3), and d(calc) = 1.444 g/cm(3), for Z = 2.