The Instability of Ni{N(SiMe3 )2 }2 : A Fifty Year Old Transition Metal Silylamide Mystery

Michelle Faust; Aimee M Bryan; Akseli Mansikkamäki; Petra Vasko; Marilyn M Olmstead; Heikki M Tuononen; Fernande Grandjean; Gary J Long; Philip P Power

doi:10.1002/anie.201505518

The Instability of Ni{N(SiMe3 )2 }2 : A Fifty Year Old Transition Metal Silylamide Mystery

Angew Chem Int Ed Engl. 2015 Oct 26;54(44):12914-7. doi: 10.1002/anie.201505518. Epub 2015 Sep 2.

Authors

Michelle Faust¹, Aimee M Bryan¹, Akseli Mansikkamäki², Petra Vasko², Marilyn M Olmstead¹, Heikki M Tuononen³, Fernande Grandjean⁴, Gary J Long⁴, Philip P Power⁵

Affiliations

¹ Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616 (USA).
² Department of Chemistry, NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland).
³ Department of Chemistry, NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland). heikki.m.tuononen@jyu.fi.
⁴ Department of Chemistry, Missouri University of Science and Technology, University of Missouri, Rolla, MO 65409-0010 (USA).
⁵ Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616 (USA). pppower@ucdavis.edu.

PMID: 26332337
DOI: 10.1002/anie.201505518

Abstract

The characterization of the unstable Ni(II) bis(silylamide) Ni{N(SiMe3 )2 }2 (1), its THF complex Ni{N(SiMe3 )2 }2 (THF) (2), and the stable bis(pyridine) derivative trans-Ni{N(SiMe3 )2 }2 (py)2 (3), is described. Both 1 and 2 decompose at ca. 25 °C to a tetrameric Ni(I) species, [Ni{N(SiMe3 )2 }]4 (4), also obtainable from LiN(SiMe3 )2 and NiCl2 (DME). Experimental and computational data indicate that the instability of 1 is likely due to ease of reduction of Ni(II) to Ni(I) and the stabilization of 4 through dispersion forces.

Keywords: dispersion effects; magnetism; nickel; silylamide; steric effects.