7 research outputs found
P-C Bond Cleavage by a Heterobimetallic Polyhydride Complex, (C5Me5)Ru(m-H)3Ir(C5Me5). Structure Determination and Fluxional Behavior of a Bridging Phosphido Complex, (C5Me5)Ru(m-PPh2)(m-H)(m-h1:h2-C6H5)Ir(C5Me5)
Toward Metal-Mediated C−F Bond Formation. Synthesis and Reactivity of the 16-Electron Fluoro Complex [RuF(dppp) 2
A Combined Gas-Phase, Solution-Phase, and Computational Study of C−H Activation by Cationic Iridium(III) Complexes
Contrasting reactivity of fluoropyridines at palladium and platinum: C-F oxidative addition at palladium, P-C and C-F activation at platinum
The divergent behavior of palladium(0) and platinum(0) is revealed in the reactivity of [M(PR3)2] (M = Pd or Pt; R = Cy or iPr) toward pentafluoropyridine and 2,3,5,6-tetrafluoropyridine. The palladium complexes react with pentafluoropyridine at 100 °C to yield the fluoride complexes trans-[Pd(F)(4-C5NF4)(PR3)2]. They do not react with 2,3,5,6-tetrafluoropyridine. The reaction of platinum(0) complexes [Pt(PR3)2] with pentafluoropyridine in THF at ambient temperature yields trans-[Pt(R)(4-C5NF4)(PR3)(PFR2)] complexes, whereas the reaction of [Pt(PCy3)2] with 2,3,5,6-tetrafluoropyridine results in C−H activation to form cis-[Pt(H)(4-C5NF4)(PCy3)2]; this complex may be converted to the trans isomer by photolysis. The cis-hydride also forms during the reaction of [Pt(PCy3)2] with C5NF5 in hexane. These reactions also contrast with earlier studies of the reactivity of the same substrates toward {Ni(PEt3)2}, which yield [Ni(F)(2-C5NF5)(PEt3)2] with pentafluoropyridine and [Ni(F)(2-C5NF4H)(PEt3)2] with tetrafluoropyridine. Thus palladium has different regioselectivity from nickel and is the least reactive. Platinum is capable of both C−F and C−H activation and is alone in the triad in undergoing rearrangement to the alkyl complex with the fluorophosphine ligand. Mechanisms for the rearrangement are proposed. The platinum dihydride complex trans-[Pt(H)2(PR3)2] reacts with pentafluoropyridine at room temperature, yielding a 1:1:1 mixture of trans-[PtH(FHF)(PR3)2], trans-[Pt(H)(4-C5NF4)(PR3)2], and trans-[Pt(R)(4-C5NF4)(PR3)(PFR2)]. Crystal structures are reported for trans-[Pd(F)(4-C5NF4)(PCy3)2]·H2O·C6H6, trans-[Pd(F)(4-C5NF4)(PiPr3)2], trans-[Pt(C6H11)(4-C5NF4)(PCy3)(PFCy2)]· CH2Cl2, and cis-[Pt(H)(4-C5NF4)(PCy3)2]