EPR study of (η5-cyclopentadienyl)nickel(I) complexes with P-and N-Donor ligands and 1,5-cyclooctadiene

Isolated Cationic Organometallic Nickel(I) Arene Complexes

“…Apart from our recently published [Ni(cod) 2 ] + complex, previously also reported with BF 4 – as an intermediate, mainly electron rich donor ligands were necessary to stabilize Ni I species, i.e. phosphines, carbenes,, β‐diketiminates or Cp – (Cyclopentadienyl), , Only a few examples of Ni I arene complexes are known, all of which are molecular compounds. Wolf and Kölle, for example, reported on Ni I ‐Cp complexes.…”

“…Such EPR interfering solvent interactions were already reported for Pd I , [21] Pt I [22] and postulated for Ni I phosphine complexes. [19] [9] 2.168 2.018 2.018 [10]…”

“…phosphines, [2] carbenes, [3,4] -diketiminates [5][6][7] or Cp - (Cyclopentadienyl). [4,8,9] Only a few examples of Ni I arene complexes are known, all of which are molecular compounds. Wolf [4] and Kölle, [10] for example, reported on Ni I -Cp complexes.…”

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

“…At a later reaction stage probably the first substitution of one cod ligand by THF occurs, before a complete replacement of the cod ligands initiates the disproportionation of the [Ni I (THF) x ][Al(O R F ) 4 ] intermediate to [Ni II (THF) 6 ][Al(O R F ) 4 ] 2 ( 3 ) and Ni 0 . As expected for Ni II species in an octahedral coordination environment, thus, bearing a Ni atom with a d 8 high‐spin electron configuration, zero field splitting is too large to observe any signal in X‐band EPR (9.5 GHz) . The same reason probably holds for complex 3 , if the octahedral distortion is small or rather non‐existent.…”

Organobimetallic Nickel‐Iron Complexes, Valence Tautomer or Charge Localized Ferrocene Ligands Upon Oxidation

“…[10][11][12] Cyclopentadienylnickel(I) (CpNi I ) coordinated by a σ-donor ligand have been reported but will generally form unreactive clusters. [13][14][15][16][17][18][19] �-Diimine ligands have been shown to support both CpNi I/III redox states, however, the ligand's noninnocence makes it difficult to assign location of the redox process. [20] Herein we report CpNi II coordinated by dRpf = 1,1'-bis(di-Rphosphino)ferrocene, R = phenyl (dppf), iso-propyl (dippf), and cyclohexyl (dcpf)).…”