title: Synthesis and structural studies of nickel(0) Tetracarbene complexes with the introduction of a new four-coordinate geometric index, τδ.
abstract: The synthesis and characterization of two homoleptic chelating nickel(0) tetracarbene complexes are reported. These are the first group 10 M(0) (M = Ni, Pd, Pt) tetracarbene complexes. These species have geometries intermediate between C2v sawhorse and tetrahedral and show high UV-vis absorption in the 350-600 nm range, with extinction coefficients (ϵ) between 5600 and 9400 M(-1) cm(-1). Density functional theory analysis indicates that this high absorptivity is due to metal-to-ligand charge transfer. In order to better describe the unusual geometries encountered in these complexes, an adjustment to the popular τ4 index for four-coordinate geometries is introduced in order to better delineate between sawhorse and distorted tetrahedral geometries.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0358, La Jolla, California 92093-0358, United States.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Reineke
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0358, La Jolla, California 92093-0358, United States.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Sampson
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0358, La Jolla, California 92093-0358, United States.
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Rheingold
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0358, La Jolla, California 92093-0358, United States.
authors.forename: Clifford P
authors.initials: CP
authors.lastname: Kubiak