title: Ambient Stable Trigonal Bipyramidal Copper(III) Complexes Equipped with an Exchangeable Axial Ligand.
abstract: A stable trigonal bipyramidal copper(III) complex, [PPN][Cu((TMS)PS3)Cl] (1, wherein PPN represents bis(triphenylphosphine)iminium), was synthesized from CuCl2/PPNCl via intramolecular copper(II) disproportionation. Under ambient conditions, the axial chloride of 1 is exchangeable in solution thus making 1 serve as an intermediate to prepare trigonal bipyramidal copper(III) derivatives, e.g., [PPN][Cu((TMS)PS3)(N3)] (2) and [Cu((TMS)PS3)(DABCO)] (3). Diamagnetic complexes 1-3 were fully characterized by X-ray crystallography, NMR, UV-vis, and Cu K-edge absorption spectroscopy. A series of UV-vis titrations were performed to investigate the relative ligand affinity toward the [Cu((TMS)PS3)] moiety, verifying the 1:1 binding equilibrium between various ligands. Compared to known copper(III) compounds, Cu K-edge absorptions of 1-3 possess lower pre-edge energy and higher shakedown transition energy, which, respectively, attribute to the electron donation from (TMS)PS3(3-) ligand and their trigonal ligand field.
authors.forename: Hao-Ching
authors.initials: HC
authors.lastname: Chang
authors.affiliation: §Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Feng-Chun
authors.initials: FC
authors.lastname: Lo
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Liu
authors.forename: Tsung-Han
authors.initials: TH
authors.lastname: Lin
authors.affiliation: §Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Liaw
authors.forename: Ting-Shen
authors.initials: TS
authors.lastname: Kuo
authors.forename: Way-Zen
authors.initials: WZ
authors.lastname: Lee