Utilizing the Perfluoronaphthalene Radical Cation as a Selective Deelectronator to Access a Variety of Strongly Oxidizing Reactive Cations.

A selective deelectronation reagent with very high potential of +2.00 (solution) / +2.41 V (solid-state) vs. Fc+/0 and based on a room temperature stable perfluoronaphthalene (naphthaleneF) radical cation salt was developed and applied. The solid-state deelectronation of commercial naph-tha-leneF with [NO]+[F{Al(ORF)3}2]- generates [naphthaleneF]+∙[F{Al(ORF)3}2]- (ORF = OC(CF3)3) in gram scale. Thermo-chemical analysis unravels the solid-state de-electronation potential of the starting [NO]+-reagent to be +2.34 V vs. Fc+/0 with [F{Al(ORF)3}2]- counterion, but only +1.14 V vs. Fc+/0 with the small [SbF6]- ion. Selective reactions demonstrate the selectivity of [naphthaleneF]+∙ for deelectronation of a multitude of organ(ometall)ic molecules and elements in solution: providing the molecular struc-tures of the acene dications [tetracene]2+, [pentacene]2+ or spectroscopic evi-dence for the carbo-nyl complex of the ferrocene dication [Fc(CO)]2+, the [P9]+ cation from white phosphor-us, the solvent-free copper(I) salt starting from copper metal and the dicationic Fe(IV)-scorpionate complex [Fe(sc)2]2+.

Activation of the GaI Cation for Bond Activation: from Oxidative Additions into C-Cl and H-P Bonds to Reversible Insertion into P4.

Although the discovery of the GaI complex salt [Ga(PhF)2-3 ][Al(ORF )4 ] (RF =C(CF3 )3 , PhF=C6 H5 F) invoked the preparation of a diverse library of cationic Ga(I) coordination complexes and clusters, studies on small molecule activation with low-valent GaI cations are scarce. Herein, a first experimental study on the reactivity of a monomeric Ga(I) cation activated with a pyridine-diimine pincer ligand (in [Ga(PDIdipp )][Al(ORF )4 ]) towards small-molecules is reported. First controlled oxidative additions of the GaI cation into C-Cl, H-P and P-P bonds are presented. Moreover, the [4+1]cycloaddition to butadienes was achieved. Intriguingly, the isolated, blue insertion product into the P-P bond of P4 allows for the quantitative release of the P4 molecule upon reaction with AlEt3 and butadienes. Reversible P4 insertion of main-group metals has previously been reported for Ge and Sn, respectively. The experimental study is supported by high-level computational analysis of the in-part reversible oxidative additions at the DLPNO-CCSD(T)/def2-TZVPP//PBEh-3c/def2-mSVP level of theory with COSMO-RS solvation in 1,2-difluorobenzene.

[Ni(CO)4 ]+ as NiI Synthon: Synthesis and Characterization of NiI Half-Sandwich and Sandwich Cations.

The stable, easily accessible salt [Ni(CO)4 ]+ [F{Al(ORF )3 }2 ]- (RF =C(CF3 )3 ) was used as a NiI synthon to generate the novel half-sandwich complexes [Ni(arene)(CO)2 ]+ (arene=C6 H6 , o-dfb=1,2-F2 C6 H4 ). By irreversible removal of CO from the equilibrium, even the rather endergonic reaction to a [Ni(o-dfb)2 ]+ salt was successful (Δr G°(solv) =+78 kJ mol-1 ). The latter displays an unprecedented slipped η3 ,η3 -sandwich structure and is the ultimate synthon to NiI -chemistry.

Isolation and Characterization of the Homoleptic Nickel(I) and Nickel(II) Bis-benzene Sandwich Cations.

A stable salt of the metalloradical [Ni(C6 H6 )2 ]+ hitherto unknown in the condensed phase was synthesized from [Ni(CO)4 ]+ [WCA]- and benzene ([WCA]- =[F{Al(ORF )3 }2 ]- ; RF =C(CF3 )3 ). Single crystal XRD reveals a remarkable asymmetrically η3 ,η6 -slipped sandwich structure. The magnetic properties of the [Ni(C6 H6 )2 ]+ cation were determined in solution and in the gas phase. Oxidation with the synergistic Ag+ /0.5 l2 system led to the salt [Ni(C6 H6 )2 ]2+ ([WCA]- )2 . All products were fully characterized by means of IR, Raman, NMR/EPR, single crystal and powder XRD.

Synthesis and Application of a Perfluorinated Ammoniumyl Radical Cation as a Very Strong Deelectronator.

The perfluorinated dihydrophenazine derivative (perfluoro-5,10-bis(perfluorophenyl)-5,10-dihydrophenazine) ("phenazineF ") can be easily transformed to a stable and weighable radical cation salt by deelectronation (i.e. oxidation) with Ag[Al(ORF )4 ]/ Br2 mixtures (RF =C(CF3 )3 ). As an innocent deelectronator it has a strong and fully reversible half-wave potential versus Fc+ /Fc in the coordinating solvent MeCN (E°'=1.21 V), but also in almost non-coordinating oDFB (=1,2-F2 C6 H4 ; E°'=1.29 V). It allows for the deelectronation of [FeIII Cp*2 ]+ to [FeIV (CO)Cp*2 ]2+ and [FeIV (CN-t Bu)Cp*2 ]2+ in common laboratory solvents and is compatible with good σ-donor ligands, such as L=trispyrazolylmethane, to generate novel [M(L)x ]n+ complex salts from the respective elemental metals.