Synthesis and Characterization of the Trihalophosphine Compounds of Ruthenium [RuX2(η6-cymene)(PY3)] (X = Cl, Br, Y = F, Cl, Br) and the Related PF2(NMe2) and P(NMe2)3 Compounds; Multinuclear NMR Spectroscopy and the X-ray Single Crystal Structures of [RuBr2(η6-cymene)(PF3)], [RuBr2(η6-cymene)(PF2{NMe2})], and [RuI2(η6-cymene)(P{NMe2}3)]

Triorganylphosphoranides: Realization of an Unusual Structural Motif Utilizing Electron Withdrawing Pentafluoroethyl Groups

Phosphoranides comprising three phosphorus carbon bonds are scarcely represented in the literature. We now utilized tris(pentafluoroethyl)phosphane, P(C₂ F₅ )₃ , and cyanobis(pentafluoroethyl)phosphane, P(C₂ F₅ )₂ (CN), featuring electron withdrawing pentafluoroethyl groups, to synthesize such compounds. Metal fluorides MF (M=Ag, Cs) add to P(C₂ F₅ )₃ yielding respective M[P(C₂ F₅ )₃ F] salts. Those M[P(C₂ F₅ )₃ F] subsequently suffer a loss of C₂ F₄ , furnishing M[P(C₂ F₅ )₂ F₂ ]. The cesium salt decomposes instantaneously when warmed to rt, whereas the silver salt decomposes slowly over several days at rt. Treatment of Ag[P(C₂ F₅ )₃ F] with 2,2'-bipyridine facilitated the isolation and structural characterization of [Ag(bipy){P(C₂ F₅ )₃ F}]. With P(C₂ F₅ )₂ (CN), AgF reacts under substitution of the cyano group yielding P(C₂ F₅ )₂ F, rather than phosphoranide formation. However, [K(18-crown-6)]F adds to P(C₂ F₅ )₂ (CN) furnishing [K(18-crown-6)][P(C₂ F₅ )₂ (CN)F]. Its structural characterization was successful, despite its tendency to undergo an exchange of substituents, yielding [K(18-crown-6)][P(C₂ F₅ )₂ F₂ ] and presumably [K(18-crown-6)][P(C₂ F₅ )₂ (CN)₂ ]. The latter forms an equilibrium with [K(18-crown-6)]CN and P(C₂ F₅ )₂ (CN) which lies well on side of the phosphane and cyanide salt.

Halogenation and Nucleophilic Quenching: Two Routes to E−X Bond Formation in Cobalt Triple‐Decker Complexes (E=As, P; X=F, Cl, Br, I)

The oxidation of [(Cp’’’Co)₂(μ,η² : η²‐E₂)₂] (E=As (1), P (2); Cp’’’=1,2,4‐tri(tert‐butyl)cyclopentadienyl) with halogens or halogen sources (I₂, PBr₅, PCl₅) was investigated. For the arsenic derivative, the ionic compounds [(Cp’’’Co)₂(μ,η⁴ : η⁴−As₄X)][Y] (X=I, Y=[As₆I₈]_0.5 (3 a), Y=[Co₂Cl_6‐nI_n]_0.5 (n=0, 2, 4; 3 b); X=Br, Y=[Co₂Br₆]_0.5 (4); X=Cl, Y=[Co₂Cl₆]_0.5 (5)) were isolated. The oxidation of the phosphorus analogue 2 with bromine and chlorine sources yielded the ionic complexes [(Cp’’’Co)₂(μ‐PBr₂)₂(μ‐Br)][Co₂Br₆]_0.5 (6 a), [(Cp’’’Co)₂(μ‐PCl₂)₂(μ‐Cl)][Co₂Cl₆]_0.5 (6 b) and the neutral species [(Cp’’’Co)₂(μ‐PCl₂)(μ‐PCl)(μ,η¹ : η¹‐P₂Cl₃] (7), respectively. As an alternative approach, quenching of the dications [(Cp’’’Co)₂(μ,η⁴ : η⁴‐E₄)][TEF]₂ (TEF=[Al{OC(CF₃)₃}₄]⁻, E=As (8), P (9)) with KI yielded [(Cp’’’Co)₂(μ,η⁴ : η⁴‐As₄I)][I] (10), representing the homologue of 3, and the neutral complex [(Cp’’’Co)(Cp’’’CoI₂)(μ,η⁴ : η¹‐P₄)] (11), respectively. The use of [(CH₃)₄N]F instead of KI leads to the formation of [(Cp’’’Co)₂(μ‐PF₂)(μ,η² : η¹ : η¹‐P₃F₂)] (12) and 2, thereby revealing synthetic access to polyphosphorus compounds bearing P−F groups and avoiding the use of very strong fluorinating reagents, such as XeF₂, that are difficult to control.

Difluorobis(pentafluoroethyl)phosphoranide: A Promising Building Block for Phosphoranidometal Complexes

Despite the fact that different metal tetrafluorophosphoranides, M[PF₄] (M = Cs, Ag, K), decompose readily, we successfully enhanced the stability of such species by the replacement of two fluorine atoms with electron withdrawing pentafluoroethyl groups. Thus, AgF adds to P(C₂F₅)₂F, yielding Ag[P(C₂F₅)₂F₂], which served as a starting material for the synthesis of mono-, bis-, and tris[difluorobis(pentafluoroethyl)phosphoranido]silver complexes. Addition of 2,2'-bipyridine allowed for the isolation of stable [Ag(bipy){P(C₂F₅)₂F₂}], whereas the reaction with the chlorides [NMe₄]Cl and CoCl₂ afforded the bis- and trisphosphoranidoargentates [NMe₄][Ag{P(C₂F₅)₂F₂}₂(OEt₂)] and [Co(NCMe)₆][Ag{P(C₂F₅)₂F₂}₃]·2MeCN, respectively. Altogether, the difluorobis(pentafluoroethyl)phosphoranido moiety serves as a novel, small, noncyclic phosphoranido ligand. It provided access to the first homoleptic phosphoranidometal complex, [Co(NCMe)₆][Ag{P(C₂F₅)₂F₂}₃]·2MeCN, which itself features the unusual structural motif of an [AgX₃]^2- ion.

N-Methylation of Amines with Methanol in the Presence of Carbonate Salt Catalyzed by a Metal-Ligand Bifunctional Ruthenium Catalyst [(p-cymene)Ru(2,2'-bpyO)(H2O)]

A ruthenium complex [(p-cymene)Ru(2,2'-bpyO)(H₂O)] was found to be a general and efficient catalyst for the N-methylation of amines with methanol in the presence of carbonate salt. Moreover, a series of sensitive substituents, such as nitro, ester, cyano, and vinyl groups, were tolerated under present conditions. It was confirmed that OH units in the ligand are crucial for the catalytic activity. Notably, this research exhibited the potential of metal-ligand bifunctional ruthenium catalysts for the hydrogen autotransfer process.

Room temperature transmetallation from tris(pentafluorophenyl)borane to cyclometallated iridium(iii)

Transmetallation with tris(pentafluorophenyl)borane produces bis-cyclometallated iridium complexes with a perfluorophenyl ancillary ligand.

A straightforward access to ruthenium-coordinated fluorophosphines from phosphorous oxyacids

For the first time, it has been shown the deoxofluorination of metal-coordinated phosphorous oxyacids is feasible using a safe and environmentally friendly “F” source and affords fluorophosphines in a mild and selective way.