UBC Theses and Dissertations
Some chemistry of organometallic nitrosyl complexes of Cr, Mo and W Chin, Teen Teen
While cationic nitrosyl complexes containing the "Cp’M(NO)₂" (Cp' =η⁵-C₅H₅ (Cp) or η⁵-C₅Me₅ (Cp*) ; M = Cr, Mo and W) fragment are well-known, cationic nitrosyl complexes containing the "Cp'M(NO)" fragment are rarely encountered. The preparation of a series of cationic nitrosyl complexes containing the latter fragment resulting from the treatment of [Cp'M(NO)X[sub m]][sub n] (M= Mo or W; X = I, Br or CI; m = 2; n = 1 or 2; M = Cr; X = I; m = 1; n = 2) with nitrosonium, [NO]⁺, or silver(I), [Ag] ⁺, salts in CH₃CN is described. Treatment of the Mo and W dihalo nitrosyl complexes, [Cp'M(NO)X₂]n, with one equivalent of [NO]⁺ or [Ag]⁺ salts in CH₃CN affords the diamagnetic monocations [Cp'M(NO)X(NCCH₃)₂]⁺ . In a special case, the treatment of Cp*Mo(NO)I₂ with one equivalent of [NO] ⁺ in CH₃CN affords the unprecedented dication [Cp*Mo(NO)(NCCH₃)₃]²⁺. These diamagnetic cations have been characterized by their elemental analyses, IR and NMR data and single-crystal X-ray structural determinations of [CpMo(NO)Cl(NCCH₃)₂][BF₄] and [Cp*Mo(NO)(NCCH₃)₃][PF₆]₂. Extension of this chemistry to [CpCr(NO)I]₂ results in the isolation of a new paramagnetic cationic complex, [CpCr(NO)(NCCH₃)₂][PF₆]. The chromium complex (also isolated as its BPh₄- salt) is characterized by its elemental analysis, IR and ESR data as well as a single crystal X-ray structure determination. Upon treatment of [CpCr(NO)(NCCH₃)₂][PF₆] with -NaOMe, the bimetallic [CpCr(NO)(OMe)]₂ complex is obtained. The synthesis and characterization of the dinitrosyl dimers [Cp*M(NO)₂]₂ (M = Cr, Mo) is described. They are prepared in moderate yields by the reduction of Cp*M(NO)₂Cl (M = Cr, Mo) with zinc amalgam in THF. The molybdenum dimer [Cp*Mo(NO)₂]₂> reacts with SnCl₂ to form the chloro complex, Cp*Mo(NO)₂Cl.
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