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Download fileStructure and Reactivity of (η-C5R5)Mo(NO)2−Halide, −Halomethyl, and −Alkyl Complexes: Consecutive Aerobic Methylene and Nitrosyl Ligand Oxidation
journal contribution
posted on 14.05.1996, 00:00 authored by Wendy L. Elcesser, Morten Sörlie, John L. HubbardCp‘Mo(NO)2(CH2X) complexes are
isolated in 80−90% yield after the treatment of the
Cp‘Mo(NO)2X complexes in
CH2Cl2 with ethereal diazomethane in the
presence of Cu powder
(Cp‘ = η-C5H5 (Cp),
η-C5(CH3)5 (Cp*); X = Cl,
Br). The Cp‘Mo(NO)2(CH2I)
derivatives are
obtained in over 90% yield by treating the
Cp‘Mo(NO)2(CH2Cl) derivatives
with NaI in THF.
Four new halomethyl complexes have been characterized by X-ray
crystallography and are
compared to the related CpMo(NO)2Br,
Cp*Mo(NO)2Cl, and
Cp*Mo(NO)2(CH3)
derivatives.
The structural data and IR data indicate the donor properties of
the halomethyl ligands to
be intermediate between halide and alkyl ligands. The
Cp‘Mo(NO)2(CH2X) complexes
react
initially with O2 to give CH2O and the
regeneration of the parent Cp‘Mo(NO)2X
complexes.
The Cp‘Mo(NO)2Cl complexes react with
O2 after an induction period to give the
well-known
Cp‘MoO2Cl complexes, NO2, NOCl, and
N2O. Exposure of
CpCr(NO)2(CH(CH3)Br) to
18O2
gives 18OCH(CH3) and 16O-labeled
CpCr(NO)2Br. The
Cp‘Mo(NO)2−alkyl complexes react
with O2 to give the corresponding
Cp‘MoO2−alkyl derivatives in 40−70% yield (alkyl =
CH3,
CH2CH3). Electrochemical data show
the Mo complexes to oxidize at 0.2−0.3 V lower than
the Cr congeners.