New ansa-2,2-bis(η-cyclopentadienyl)propane molybdenum and tungsten compounds and intramolecular hydrogen–deuterium exchange in methyl-hydride and ethyl-hydride derivatives

Autor: Chernega, Alexander, Cook, Jessica, L. H. Green, Malcolm, Labella, Luca, J. Simpson, Stephen, Souter, Joanne, H. H. Stephens, Adam
Zdroj: Journal of the Chemical Society, Dalton Transactions; January 1997, Vol. 1997 Issue: 18 p3225-3244, 20p
Abstrakt: The new compounds [Mo2Cl4(OEt)4(EtOH)2], [Mo{(η-C5H4)C(C5H10 )(η-C5H4)}Cl2], [W{(η-C5H4)CMe2(η-C 5H4)Cl2][BF4], [W{(η-C5H4)CMe2(η-C 5H4)}(SPh)2],* [W{(η-C5H4)CMe2(η-C 5H4)}(SPri)2], [W{(η-C5H4)CMe2(η-C 5H4)}(SPri)(NCMe)][BF4], [M{(η-C5H4)CMe2(η-C 5H4)}(NCMe)Cl][PF6] (M = Mo or W),* [W{(η-C5H4)CMe2(η-C 5H4)}(PPh3)Cl][PF6], [W{(η-C5H4)CMe2(η-C 5H4)}(CNC6H3Me2- 2,6)Cl][PF6],* [W{(η-C5H4)CMe2(η-C 5H4)}(η2-C2H4 )H][B(C6F5)4],* [W{(η-C5H4)CMe2(η-C 5H4)}Et(NCMe)][B(C6F5) 4], [W{(η-C5H4)CMe2(η-C 5H4)}Et(Cl)],* [W{(η-C5H4)CMe2(η-C 5H4)}Et(Cl)][BF4], [W{(η-C5H4)CMe2(η-C 5H4)}H3][PF6],* [M{(η-C5H4)CMe2(η-C 5H4)}Et2] (M = Mo or W),* [W{(η-C5H4)CMe2(η-C 5H4)}Et(I)], [W{(η-C5H4)CMe2(η-C 5H4)}Et(O2CPh)], [W{(η-C5H4)CMe2(η-C 5H4)}Et(X)] (X = H or D), [W{(η-C5H4)CMe2(η-C 5H4)}(CD3)2], [W{(η-C5H4)CMe2(η-C 5H4)}(CD3)I],* [W{(η-C5H4)CMe2(η-C 5H4)}(CD3)H] and [W{(η-C5H4)CMe2(η-C 5H4)}Me(D)] have been prepared. The asterisk indicates the crystal structure has been determined. Evidence is presented for intramolecular hydrogen–deuterium scrambling processes in the methyl- and ethyl-hydride compounds. Preliminary variable-temperature 1H NMR studies on [W{(η-C5H4)CMe2(η-C 5H4)}HA(HB)2] [PF6] give a value for J(AB) of 16 000 Hz at -70 °C.
Databáze: Supplemental Index