Dispersion Forces, Disproportionation, and Stable High-Valent Late Transition Metal Alkyls

David J Liptrot; Jing-Dong Guo; Shigeru Nagase; Philip P Power

doi:10.1002/anie.201607360

Dispersion Forces, Disproportionation, and Stable High-Valent Late Transition Metal Alkyls

Angew Chem Int Ed Engl. 2016 Nov 14;55(47):14766-14769. doi: 10.1002/anie.201607360. Epub 2016 Oct 25.

Authors

David J Liptrot¹, Jing-Dong Guo², Shigeru Nagase², Philip P Power¹

Affiliations

¹ Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA.
² Fukui Institute for Fundamental Chemistry, Kyoto University, Takano Nishi-Hiraki-Cho 34-4, Sakyo-ku, Kyoto, 606-8103, Japan.

PMID: 27778428
DOI: 10.1002/anie.201607360

Abstract

The transition metal tetra- and trinorbornyl bromide complexes, M(nor)₄ (M=Fe, Co, Ni) and Ni(nor)₃ Br (nor=1-bicyclo[2.2.1]hept-1-yl) and their homolytic fragmentations were studied computationally using hybrid density functional theory (DFT) at the B3PW91 and B3PW91-D3 dispersion-corrected levels. Experimental structures were well replicated; the dispersion correction resulted in shortened M-C bond lengths for the stable complexes, and it was found that Fe(nor)₄ receives a remarkable 45.9 kcal mol^-1 stabilization from the dispersion effects whereas the tetragonalized Co(nor)₄ shows stabilization of 38.3 kcal mol^-1 . Ni(nor)₄ was calculated to be highly tetragonalized with long Ni-C bonds, providing a rationale for its current synthetic inaccessibility. Isodesmic exchange evaluation for Fe(nor)₄ confirmed that dispersion force attraction between norbornyl substituents is fundamental to the stability of these species.

Keywords: density functional calculations; dispersion forces; high oxidation states; organometallics; transition metals.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.