Organometall‐Imide – höhervalente Derivate der d‐Metall‐Säuren, 3. Synthese und Reaktionen von (Pentamethylcyclopentadienyl)(imido)‐Komplexen des Molybdäns und Wolframs und eine effiziente Strategie zur Synthese der Organometallate NBu 4 [Cp * MO 3 ] (M = Mo, W)

Organometallic Imido Complexes – Highervalent Derivatives of the d‐Metal Acids, 3 [4b] . – Synthesis and Reactions of Pentamethylcyclopentadienyl Imido Complexes of Molybdenum and Tungsten and an Efficient Strategy for the Synthesis of the Organometallates NBu 4 [Cp * MO 3 ] (M = Mo, W) A convenient and new entry into the chemistry of highvalent pentamethylcyclopentadienyl halfsandwich complexes of molybdenum and tungsten is described. The reaction of Mo‐(N t Bu) 2 Cl 2 or W(N t Bu) 2 Cl 2 (py) 2 with Cp * Li (Cp * = η 5 ‐C 5 Me 5 ) provides a high‐yield route to new complexes Cp * Mo‐(N t Bu) 2 Cl ( 1a ) and Cp * W(N t Bu) 2 Cl ( 1b ) which are converted into a variety of diimido, monoimido, and oxo derivatives. Treatment of 1a,b with MeLi yields the highly volatile methyl derivatives Cp * Mo(N t Bu) 2 Me ( 2a ) and Cp * W(N t Bu) 2 Me ( 2b ), while protolysis of 1a,b with an excess of HCl gas leads to selective cleavage of only one imido function with formation of Cp * Mo(N t Bu)Cl 3 ( 3a ) and Cp * W(N t Bu)Cl 3 ( 3b ). In contrast, protolysis of 1a,b with aqueous HCl provides a high‐yield route to the well‐known organometallic oxides [Cp * MoO 2 ]‐(μ‐O) ( 4a ) and [Cp * WO 2 ](μ‐O) ( 4b ). These two key compounds are easily converted into the organomolybdate and organotungstate salts NBu 4 [Cp * MoO 3 ] ( 5a ) and NBu 4 [Cp * WO 3 ] ( 5b ) by cleavage of the M–O–M bridge with NBu 4 [OH]. The X‐ray structure of 3a is reported.