Reaction studies on some functionalized alkyl transition metal compounds and the crystal structure of [Cp(CO)3W{(CH2)3NO2}]

The reactions of the halogenoalkyl compounds Cp(CO)₃W{(CH₂)_nX}] (Cp = η⁵-C₅H₅; n = 3-5; X = Br, I) and Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with the nucleophiles Z = CN⁻ and gave compounds of the type Cp(CO)₃W{(CH₂)_nZ}] for the tungsten compounds, whilst cyclic carbene compounds were obtained from the reactions of the molybdenum compound. The reactions of Cp(CO)₃W{(CH₂)_nBr}] (n = 3, 4) and Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with gave Cp(CO)₃W{(CH₂)_nONO₂}] and Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃ONO₂}], respectively. The reaction of Cp(CO)₃W{(CH₂)_nBr}] with AgNO₂ gave Cp(CO)₃W{(CH₂)_nNO₂}]. In the solid state the complex Cp(CO)₃W{(CH₂)₃NO₂}] crystallizes in a distorted square pyramidal geometry. In this molecule the nitropropyl chain deviates from the ideal, all-trans geometry as a result of short, non-hydrogen intermolecular N-O?O-N contacts. The reactions of the heterobimetallic compounds Cp(CO)₃W{(CH₂)₃}ML_y] {ML_y = Mo(CO)₃Cp, Mo(CO)₃Cp^∗ and Mo(CO)₂(PMe₃)Cp; Cp^∗ = η⁵-C₅(CH₃)₅} with PPh₃ and CO were found to be totally metalloselective, with the ligand always attacking the metal site predicted by the reactions of the corresponding monometallic analogues above with nucleophiles. Thus the compounds Cp(CO)₃W{(CH₂)₃}C(O)ML_z] {ML_z = Mo(CO)₂YCp, Mo(CO)₂YCp^∗ and Mo(CO)Y(PMe₃)Cp; Y = PPh₃ or CO} were obtained. Similarly, the reaction of Cp(CO)₂Fe{(CH₂)₃}Mo(CO)₂(PMe₃)Cp] with CO gave only Cp(CO)₂Fe{(CH₂)₃C(O)}Mo(CO)₂(PMe₃)Cp]. Hydrolysis of the bimetallic compound, Cp(CO)₃W(CH₂)₃C(O)Mo(CO)(PPh₃)(PMe₃)Cp], gave the carboxypropyl compound Cp(CO)₃W{(CH₂)₃COOH}]. Thermolysis of the compound Cp(CO)₂Fe(CH₂)₃Mo(CO)₃(PMe₃)Cp] gave cyclopropane and propene, indicating that β-elimination and reductive processes had taken place.