title: Sequential Gas-Phase Activation of Carbon Dioxide and Methane by [Re(CO)2]+: The Sequence of Events Matters!
abstract: The potential of carbonyl rhenium complexes in activating and coupling carbon dioxide and methane has been explored by using a combination of gas-phase experiments (FT-ICR mass spectrometry) and high-level quantum chemical calculations. While the complexes [Re(CO)x]+(x = 0, 1, 3) are thermally unreactive toward CO2, [Re(CO)2]+abstracts one oxygen atom from this substrate spontaneously at ambient conditions. Based on13C and18O labeling experiments, the newly generated CO ligand is preferentially eliminated, and two mechanistic scenarios are considered to account for this unexpected finding. The oxo complex [ORe(CO)2]+reacts further with CH4to produce the dihydridomethylene complex [ORe(CO)(CH2)(H)2]+. However, coupling of the CO and CH2ligands to form CH2═C═O does not take place. Further, the complexes [Re(CO)x(CH2)]+(x = 1, 2), generated in the thermal reaction of [Re(CO)x]+(x = 1, 2) with CH4, are inert toward CO2. Mechanistic insight on the origin of this remarkable reactivity pattern has been derived from detailed quantum chemical calculations.
authors.affiliation: Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Shaodong
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 135, 10623 Berlin, Germany.|Institute of Theoretical Chemistry, Jilin University , Changchun 130023, People's Republic of China.
authors.forename: Jilai
authors.identifier: 0000-0002-3363-9164
authors.initials: J
authors.lastname: Li
authors.affiliation: Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Marjan
authors.initials: M
authors.lastname: Firouzbakht
authors.affiliation: Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Schlangen
authors.affiliation: Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Helmut
authors.identifier: 0000-0002-3369-7997
authors.initials: H
authors.lastname: Schwarz