Synthesis of coordinatively unsaturated diphosphine nickel(II) and palladium(II)β-agostic ethyl cations: X-ray crystal structure of [Ni{Bu^t₂P(CH₂)₂PBu^t₂}(C₂H₅)][BF₄]

T‐Shaped Platinum Boryl Complexes: Synthesis and Structure

“…[11b, [12][13][14]18] In the solid state all cationic compounds 12-18 show no solvent molecules coordinating to [8] in the cationic boryl complexes (short Pt···H(C) and Pt···C distances; hydrogen atoms were assigned to idealized positions). 2 CH 2 Cl 2 ) are omitted for clarity.…”

The Electronic Structure of the Tris(ethylene) Complexes [M(C2H4)3] (M=Ni, Pd, and Pt): A Combined Experimental and Theoretical Study

“…In the following we have therefore analyzed changes in electronic structure of these textbook examples of neutral d 10 nickel ethylene complexes on protonation. As demonstrated by Spencer and co-workers [42] earlier the b-agostic cationic nickel d 8 spe- (Figure 7) highlights a simple rule: The agostic hydrogen atom faces a zone of locally increased Lewis acidity in the valence shell of the transitionmetal atom. Hence, the C À H bond activation is controlled by the local Lewis acidity of the transition-metal atom in…”

Nickel

“…Protonation of (diphosphane)nickel(0)-ethene complexes with HBF 4 · OEt 2 results in the formation of the corresponding cationic three-coordinate nickel(II)alkyl complexes, in which a b-agostic hydrogen is present [23]. Figure 5.2 illustrates the structure of [Ni(dbpe)(ethyl)] with an agostic Ni-H distance of 1.64 Å [23].…”

“…Figure 5.2 illustrates the structure of [Ni(dbpe)(ethyl)] with an agostic Ni-H distance of 1.64 Å [23]. NMR spectroscopy at 20 8C revealed a multiplet at -1.24 ppm for the three protons at the b-carbon, whereas at -100 8C a broad signal at -5.8 ppm is assigned to the agostic hydrogen [23]. NMR spectroscopy at 20 8C revealed a multiplet at -1.24 ppm for the three protons at the b-carbon, whereas at -100 8C a broad signal at -5.8 ppm is assigned to the agostic hydrogen [23].…”