New η-cycloheptatrienyl tungsten compounds and the intercalation of [M(η-C7H7)(η-C5H4Me)](M = Mo or W) into ZrS2

Abstract

The compound [W(η-C₇H₇)(η-C₇H₉)]1 is formed in gram quantities by reduction of WCl₆ with sodium amalgam in the presence of cycloheptatriene. The compound 1 with iodine in acetonitrile gives [W(η-C₇H₇)(MeCN)I₂]2 and this reacts with PMe₃ forming [W(η-C₇H₇)(PMe₃)I₂]. Oxidation of 1 with bromine in acetonitrile yields [W(η-C₇H₇)(MeCN)Br₂] and with bromine in tetrahydrofuran followed by addition of PMe₃ gives [W(η-C₇H₇)(PMe₃)Br₂]. Reduction of 2 with sodium amalgam in the presence of 1,2-bis(dimethylphosphino)ethane (dmpe) affords [W(η-C₇H₇)(dmpe)I]. Compound 2 also reacts with Na(C₅H₄R)(R = H or Me) and lithium indenide to give the mixed-sandwich compounds [W(η-C₇H₇)(η-C₅H₄R)](R = H or Me) and [W(η-C₇H₇)(η-C₉H₇)] respectively. The sandwich compounds [M(η-C₇H₇)(η-C₅H₄Me)](M = Mo or W) and ZrS₂ form the intercalates {ZrS₂[M(η-C₇H₇)(η-C₅H₄Me)]_x}.