title: Synthesis and reactivity of the hydrido- and alkylrhenium methylidene complexes Cp*(PMe3)2(R)Re=CH2 (R = H, CH3).
abstract: Protonolysis of the dimethylrhenium(III) compound Cp(PMe(3))(2)Re(CH(3))(2) (3) led to formation of the highly reactive hydridorhenium methylidene compound [Cp(PMe(3))(2)Re(CH(2))(H)][OTf] (4), which was characterized spectroscopically at low temperature. Although 4 decomposed above -30 degrees C, reactivity studies performed at low temperature indicated it was in equilibrium with the coordinatively unsaturated methylrhenium complex [Cp(PMe(3))(2)Re(CH(3))][OTf] (2). Methylidene complex 4 was found to react with PMe(3) to afford [Cp(PMe(3))(3)Re(CH(3))][OTf] (6) and with chloride anion to give Cp(PMe(3))(2)Re(Me)Cl (7). When BAr(f) anion was added to 4, the thermally stable methylrhenium methylidene complex [Cp(PMe(3))(2)Re(CH(2))(CH(3))][BAr(f)] (8) was isolated upon warming to room temperature. The mechanisms of formation of both 4 and 8 are discussed in detail, including DFT calculations. The novel carbonyl ligated complex Cp(CO)(2)Re(CH(3))OTf (12) was prepared, isolated, and found to not undergo migration reactions to form methylidene complexes.
authors.affiliation: Department of Chemistry, University of California-Berkeley, and Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94702, USA.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Krumper
authors.forename: Richard L
authors.initials: RL
authors.lastname: Martin
authors.forename: P Jeffrey
authors.initials: PJ
authors.lastname: Hay
authors.forename: Cathleen M
authors.initials: CM
authors.lastname: Yung
authors.forename: John
authors.initials: J
authors.lastname: Veltheer
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman