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 ).     

Tetraphosphor-trithio-dihalogenide und -pseudohalogenide

Tetraphosphorus Trithio Dihalides and Pseudohalides P₄S₃Cl₂, P₄S₃Br₂, P₄S₃(CN)₂ and P₄S₃(NCS)₂ were prepared by reacting α-P₄S₃I₂ with the corresponding silver halides and pseudohalides, respectively. The ³¹P n.m.r. data of the compounds are reported.     

Correlation of the Rates of Solvolysis of the Benzhydryldimethylsulfonium Ion. Application of the Aromatic Ring Parameter(1)

Values for the specific rates of solvolysis of the benzhydryldimethylsulfonium ion in 34 solvents have been analyzed using various forms of the extended Grunwald-Winstein equation. The specific rates are insensitive toward changes in solvent nucleophilicity (N(T)) values, and they correlate best against a combination of Y(+) values (based on the solvolyses of the 1-adamantyldimethylsulfonium ion) and aromatic ring parameter (I) values. Common-molecule return is observed, being especially powerful in solvents rich in fluoro alcohol; the logarithm of the associated mass law constant correlates inversely with the solvent N(T) values. The product selectivities in ethanol-water mixtures are also consistent with an S(N)1 mechanism for the solvolyses.