[Ni(cod)₂][Al(OR^F)₄], a Source for Naked Nickel(I) Chemistry

Abstract

The straightforward synthesis of the cationic, purely organometallic NiI salt [Ni(cod)2]+[Al(ORF)4]− was realized through a reaction between [Ni(cod)2] and Ag[Al(ORF)4] (cod=1,5‐cyclooctadiene). Crystal‐structure analysis and EPR, XANES, and cyclic voltammetry studies confirmed the presence of a homoleptic NiI olefin complex. Weak interactions between the metal center, the ligands, and the anion provide a good starting material for further cationic NiI complexes.

Reactivity of [Ni(cod)2][Al(ORF)4] towards Small Molecules and Elements

“…In contrast, when investigating the dried residue obtained after filtration and removal of the solvent – besides an amorphous background – additional reflections were observed, which neither match with the strong reflections simulated from the cell of the single X‐ray structure of 1 , nor with the simulated diffraction pattern of the known crystal structures of Ag[Al(O R F ) 4 ] or [Ag(cod) 2 ][Al(O R F ) 4 ] ( 2 ) (Figure S1, Supporting Information). These reflections at large 2 Θ values cannot be attributed to any appropriate known substance, but we assume that it correlates to a contamination of 1 with Ag or an Ag‐Ni alloy, probably located on the crystal surface.…”

“…[(Ag(PPh 3 ) 4 ][Al(O R F ) 4 ] instead of [Ni(PPh 3 ) 3 ][Al(O R F ) 4 ]. However, in X‐ray structure analyses of single crystals the metal coordinated by cod in [Ni(cod) 2 ][Al(O R F ) 4 ] ( 1 ) was unambiguously determined as Ni, also by comparison to the analogous structure with silver as metal ion . Powder diffraction of large mortared crystals of 1 and phase analysis did not show any impurities (Figure , crystalline sample).…”

“…Ni(cod) 2 was prepared according to the literature . Ag[Al(O R F ) 4 ], [Ag(cod) 2 ][Al(O R F ) 4 ] ( 2 ) and [Ni(cod) 2 ][Al(O R F ) 4 ] ( 1 ) were prepared as described previously , . Ag[Al(O R F ) 4 ] is also commercially available at http://www.iolitec.de.…”

A Simple Homoleptic Gallium(I) Olefin Complex: Mimicking Transition‐Metal Chemistry at a Main‐Group Metal?

“…Ag + : q = 88.58; Rh + with a d 8 configuration: q = 10.08; see Table 1). [3] Vibrational spectra show the expected redshift, despite the weak coordination of the COD ligands with on average d db-Ga = 299.9 pm (r vdW (Ga + C) = 380 ppm). Thus, the C = C stretching mode of the COD ligand in 1 at 1635 (IR)/1639 cm À1 (Raman) shows a redshift by 21-22 cm À1 compared to the free ligand (n C=C = 1656 (IR) [34] /1661 cm À1 (Raman)).…”