Vanadium complexes pentadienyl

The formation of the 17-electron paramagnetic vanadium complex is not surprising in view of the known corresponding carbonyl complex, however the 16-electron titanium derivative is unexpected in view of the ready formation of the 18-electron biscarbonyl and bistrifluorophos-phine metal complexes containing the 5-cyclopentadienyl ligand. The solid-state structure of the PF3 adduct of bis[2,4-dimethyl-(pentadienyl)]titanium has recently been determined (111) and is shown in Fig. 20. The corresponding vanadium complex is isomorphous. The metal-PF3 distances are 2.326(Ti) and 2.275(V) A. 

HIGH-VALENT MONO- -PENTAMETHYLCYCLO-PENTADIENYL)VANADIUM AND MOLYBDENUM COMPLEXES... 

Direct addition of PF3 to 5-pentadienyl metal complexes offers an alternative synthetic route (method G) and this has been reported in the case of the formation of bis(2,4-dimethylpentadienyl)trifluoro-phosphine complexes of titanium and vanadium [M(C7H11)2PF3] (M = Ti, V) (Scheme 11) 111). 

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