Synthesis and Characterization of a Linear, Two-Coordinate Pt(II) Ketimide Complex

Andrew W Cook; Peter Hrobárik; Peter L Damon; Daniel Najera; Branislav Horváth; Guang Wu; Trevor W Hayton

doi:10.1021/acs.inorgchem.9b02443

Synthesis and Characterization of a Linear, Two-Coordinate Pt(II) Ketimide Complex

Inorg Chem. 2019 Dec 2;58(23):15927-15935. doi: 10.1021/acs.inorgchem.9b02443. Epub 2019 Nov 11.

Authors

Andrew W Cook¹, Peter Hrobárik², Peter L Damon¹, Daniel Najera¹, Branislav Horváth³, Guang Wu¹, Trevor W Hayton¹

Affiliations

¹ Department of Chemistry and Biochemistry , University of California Santa Barbara , Santa Barbara , California 93106 , United States.
² Department of Inorganic Chemistry, Faculty of Natural Sciences , Comenius University , SK-84215 Bratislava , Slovakia.
³ Central NMR Laboratory, Faculty of Pharmacy , Comenius University , SK-83232 Bratislava , Slovakia.

PMID: 31710476
DOI: 10.1021/acs.inorgchem.9b02443

Abstract

Herein we report the synthesis and characterization of a linear, two-coordinate Pt(II) ketimide complex, Pt(N═C^tBu₂)₂ (1), formed via the reaction of PtCl₂(1,5-COD) with 2 equiv of Li(N═C^tBu₂). Also generated in the reaction is the bimetallic complex [(^tBu₂C═N)Pt(μ-N,C-N═C(^tBu)C(Me)₂CH₂)Pt(N═C^tBu₂)] (2). Both complexes 1 and 2 have been characterized by NMR spectroscopy and X-ray crystallography. Notably, complex 1 exhibits short Pt-N distances (av. Pt-N = 1.817 Å) and an unusually deshielded ¹⁹⁵Pt chemical shift (δ_Pt = -629 ppm) with a large ¹J(¹⁹⁵Pt,¹⁴N) coupling constant (537 Hz). These data, in combination with a detailed density functional theory electronic structure analysis, reveal the presence of highly covalent Pt═N multiple bonds formed by a combination of σ-donation, π-donation, and π-backdonation.