Synthesis and characterization of dioxocomplexes of molybdenum with (eta-C5H5)Co{P(O)(OEt)(2)}(3), C5H4(SiMe3) and 1,3-C5H3(SiMe3)(2) ligands. X-ray crystal structure of [(eta-C5H5)Co{P(O)(OEt)(2)}(3)]MoO2Cl

The interaction of (NH4)(2)Mo2O7 with Me3SiCl in 1,2-dimethoxyethane (dme) gives, in a one pot reaction, the known dioxo-compound MoCl2O2(dme) (1). Di oxo-molybdenum complexes of the type (L)MoO2Cl (L=monoanionic, formally tri dentate, ancillary ligand like (eta-C5H5)Co{P(O)(OEt)(2)}(3), L-OEt (2) C5H 4(SiMe3), Cp-tms (3) and 1,3-C5H3(SiMe3)(2), Cp-2tms (4)) have been prepare d using 1 as the starting material. Other known oxo complexes are also easi ly accessible from 1, for example, the reaction with CpTl, PMe3 and Li[(Me3 SiN)(2)CPh]. tmda affords CpMoO2Cl (5), MoOCl2(PMe3)(3) (7) and Mo(O)(2){(M e3SiN)(2)CPh}(2) (8), respectively. Complex 4 acts as a good catalyst of th e ore-transfer model reaction from dimethylsulfoxide to PPh3 at room temper ature. Complex (L-OEt)MoO2Cl (2) has been structurally characterized by X-r ay crystallography. (C) 1999 Elsevier Science Ltd. All rights reserved.