NEW ANSA-2,2-BIS(ETA-CYCLOPENTADIENYL)PROPANE MOLYBDENUM AND TUNGSTENCOMPOUNDS AND INTRAMOLECULAR HYDROGEN-DEUTERIUM EXCHANGE IN METHYL-HYDRIDE AND ETHYL-HYDRIDE DERIVATIVES

The new compounds [Mo2Cl4(OEt)(4)(EtOH)(2)], [Mo{(eta C5H4)C(C5H10)(et a-C5H4)}Cl-2], [W{(eta-C(5)J(4))CMe2(eta-C5H4)-Cl-2][BF4], [W{(eta-C5H 4)CMe2(eta-C5H4)}(SPh)(2)] [W{(eta-C5H4)CMe2(eta-C5H4)}(SPri)(2)], [W {(eta-C5H4)CMe2-(eta-C5H4)}(SPri)(NCMe] ][BF4], [M{(eta-C5H4)CMe2(eta- C5H4)}(NCMe)Cl][PF6] (M = Mo or W), [W{(eta-C5H4)-CMe2(eta-C5H4) ) (P Ph3)Cl][PF5], (eta-C5H4)CMe2(eta-C5H4)}(CNC6H3Me2-2,6)Cl][PF6], ta-C5 H4)CMe2(eta-C5H4)}(eta(2)-C2H4)][B(C6F5)(4)], [eta-C5H4)}CMe2(eta-C5H 4)}Et(NCMe)][B(C6F5)(4)], ta-C5H4)CMe2(eta-C5H4)}(eta(2)-C2H4)H][B(C6F 5)(4), (W{(eta-C5H4)CMe2(<eta-C5H4)}Et(CI)][BF4], [W{(eta-C5H4)CMe2(e ta-C5H4)}H-3][PF6], [M{(eta-C5H4)-CMe2(eta-C5H4)} Et-2] (M = Mo or W) , [W{(eta-C5H4)CMe2(eta-C5H4)}Et(I)], [W{(eta-C5H4)CMe2(eta-C5H4)}Et- (O2CPh)], [W{(eta-C5H4)CMe2(eta-C5H4)}Et(X)](X = H or D), [W{(eta-C5H4 )CMe2(eta-C5H4)}(CD3)(2)], [W{(eta-C5H4)-CMe(eta-C5H4)} (CD3)I], [W{( eta-C5H4)CMe2(eta-C5H4)}(CD3)H] and {W{(eta-C5H4)CMe2(eta-C5H4)}Me(D)] have been prepared, The asterisk indicates the crystal structure has been determined. Evidence is presented for intramolecular hydrogen-deu terium scrambling processes in the methyl-and ethyl-hydride compounds. Preliminary variable-temperature LH NMR studies on [W{(eta-C5H4)CMe2( eta-C5H4)}H-A(H-B)(2)][PF6] give a value for J(AB) of 16 000 Hz at -70 degrees C.