Perfluormethyl-Element-Liganden. XXXV. Reaktivität metallierter Phosphane und Arsane des Typs π-C5H5(CO)3MER2 (M  Cr,Mo, W; E  P,As; R  CF3, CN)

Perfluoromethyl-Element-Ligands. XXXV. Reactivity of Metallated Phosphanes and Arsanes of the Type π-C₅H₅(CO)₃MER₂ (M ? Cr, Mo, W; E ? P, As; R ? CF₃, CN) The influence of the complex fragments π-C₅H₅(CO)₃M (M ? Cr, Mo, W) on the basicity of the metallated phosphanes or arsanes π-C₅H₅(CO)₃MER₂ (E ? P, As; R ? CF₃, CN) has been investigated by reactions with sulfur, methyliodide, fluorotrichloromethane, and W(CO)₅THF, respectively. π-C₅H₅(CO)₃ME(CF₃)₂ (E ? P: 1a–c ; E ? As: 2a–c ) react with sulfur only for E ? P to give the complexes π-C₅H₅(CO)₃P(S)(CF₃)₂ ( 5a–c ) in good yield. The attempted thermal transformation of the phosphane sulfides to η² coordinated (CF₃)₂P?S complexes proves unsuccessful. The reactions of 1a–c, 2a–c and π-C₅H₅(CO)₃MP(CN)₂ ( 3a–c ) with CH₃I or CCl₃F do not lead to onium salts, but to cleavage of the M–E bonds forming π-C₅H₅(CO)₃MX (X ? I, Cl) and CH₃ER₂ and R₂ECCl₂F, respectively. The reactivity depends on ER₂ and M: P(CF₃)₂ > P(CN)₂ > As(CF₃)₂; Cr > Mo > W. Due to the low donor ability of the complexes 1a–c, 2a–c and 3a–c binuclear compounds π-C₅H₅(CO)₃MER₂W(CO)₅ (E ? As, R ? CF₃: 11a–c ; E ? P, R ? CN: 12a–c ; ER₂?P(CN)Ph: 13a, b ) are obtained only with the highly reactive W(CO)₅THF. In case of the (CF₃)₂P bridged derivatives spontaneous CO-elimination leads to the threemembered ring systems ( 10a–c ).