Unusual Ar-H/Rh-H J(HH) NMR coupling in complexes of rhodium(III): experimental evidence and theoretical support for an eta1-arene structure

Jennifer R Krumper; Michael Gerisch; Alessandra Magistrato; Ursula Rothlisberger; Robert G Bergman; T Don Tilley

doi:10.1021/ja047665b

Unusual Ar-H/Rh-H J(HH) NMR coupling in complexes of rhodium(III): experimental evidence and theoretical support for an eta1-arene structure

J Am Chem Soc. 2004 Oct 6;126(39):12492-502. doi: 10.1021/ja047665b.

Authors

Jennifer R Krumper¹, Michael Gerisch, Alessandra Magistrato, Ursula Rothlisberger, Robert G Bergman, T Don Tilley

Affiliation

¹ Department of Chemistry, University of California, Lawrence Berkeley National Laboratory, Berkeley, California 94702, USA.

PMID: 15453783
DOI: 10.1021/ja047665b

Abstract

The synthesis and structural properties of three new hydridorhodium(III) complexes are reported. Hydrogenolysis of the cyclometalated rhodium dichloride complexes [RhCl(2)[(S,S)-benbox(Me(2))]] (2a-c) leads to formation of the new complexes [RhCl(2)(H)[(S,S)-ip-benbox(Me(2))H]] (3a-c) in 45% to 85% yield. Compounds 3a-c were found to have unusual features by NMR spectroscopy: in particular, downfield shifted aryl proton resonances (8.88-9.03 ppm) that were coupled to the rhodium hydride resonances. Using X-ray crystallographic studies, a variety of solid- and solution-state characterization techniques, and DFT calculations, these features were attributed to the presence of weak pi-type eta(1)-arene interactions in 3a-c.