| Abstract: | Complex Chemistry of Reactive Organic Compounds. XLV. Organometallic Methanediazo Complexes: Protonation and Cycloaddition The reactions of the methanediazo tungsten complex (η5-C5H5)W(CO)2(N2CH3) ( 1 ) with protic acids are strongly governed by solvent effects: while trifluoromethylsulfonic acid induces clean protonation with formation of the ionic derivative (η5-C5H5)W(CO)2(HN2CH3)]+CF3SO3? ( 3 ) when diethylether is used as a solvent, compound 4 is formed in the presence of acetonitril which latter solvent has good coordination capabilities itself. Compound 4 originates from a novel type of cycloaddition reaction in which the protonated species of composition (η5-C5H5)W(CO)(CH3CN)(HN2-CH3)]+CF3SO3? is involved. Complete elimination of the nitrogeneous ligand ensemble with concomitant formation of the halogen complex (η5-C5H5)W(CO)2Br3 ( 5 ) occurs upon treatment of 1 with hydrogen bromide. |
