Reactivity of a β-diketiminate ytterbium(II) hydride with cyclopentadiene derivatives

Abstract

Cyclopentadienyl ligands are ubiquitous in lanthanide chemistry and have been used extensively to stabilize low-valent lanthanide(II) complexes. We now report the reactions of the β-diketiminate ytterbium(II) hydride [(BDI^Dipp)Yb(H)]₂ (BDI^Dipp = HC{C(Me)NDipp}₂, Dipp = 2,6-ⁱPr₂C₆H₃) with tetramethylcyclopentadiene, pentamethylcyclopentadiene, indene, and fluorene; to provide ready access to the heteroleptic ytterbium(II) η⁵-C₅R₅ cyclopentadienides with extrusion of hydrogen gas. The tetramethylcyclopentadienyl, pentamethylcyclopentadienyl, indenyl, and fluorenyl compounds were characterized by ¹H and ¹³C{¹H} NMR, elemental analysis, and single crystal X-ray diffraction. These data indicated that each heteroleptic cyclopentadienide exists as a mononuclear species in both solution and the solid state, formulated with retention of the oxidation state on the ytterbium(II) center. Additionally, the pentamethylcyclopentadienyl derivative was characterized by single crystal neutron diffraction, a study that explored the nature of an agostic interaction between a methyl group and the ytterbium(II) center.

Graphical Abstract

Keywords:

• Ytterbium(II) hydrides
• cyclopentadienyls
• organoytterbium
• single crystal X-ray diffraction
• single crystal neutron diffraction

Acknowledgements

M.J.E, M.D.A and G.M.R would like to acknowledge the award of beam-time on the KOALA instrument at ANSTO (Proposal P9354 and DB9677).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

G.M.R acknowledges the award of a Victoria University of Wellington Doctoral Scholarship and a MacDiarmid Institute Doctoral Scholarship. Financial support from the University Research Fund at Victoria University of Wellington (M.D.A) and MacDiarmid Institute for Advanced Materials and Nanotechnology.