Synthesis, X-Ray Crystal Structure and Reactivity of [(tmeda)(p-tolyl)Pd(μ2-I)AgL], an Unusual Silver Iodide Complex; Reversible CO Insertion into the Pd-C Bond of [Pd(PPh3)(p-tolyl)L] (L - = [(C5H5)Co{P(OR)2O}3] - , R = Me, Pri)

Abstract

The palladium complexes [Pd(PPh3)(aryl)LOR] (aryl = Ph, p-tolyl; LOR¯ = [(C5H5)Co{P(OR)2O}3]¯, R = Me, Pri) have been prepared by reaction of [PdI(aryl)(tmeda)] (tmeda = N,N,N′,N′-tetramethyl-ethylenediamine) with the silver salts AgLOR in the presence of PPh3. The complexes [Pd(PPh3)(aryl)LOR] rapidly and reversibly insert carbon monoxide to yield the aroyl palladium complexes [Pd(PPh3)(C(O)- p-tolyl)LOR] (R = Me, Pri ). The palladium iodide complex [PdI(p-tolyl)(tmeda)] and the silver salt AgLOR in the absence of PPh3 form an unusual adduct [(p-tolyl)(tmeda)Pd(µ2-I)AgLOMe] that contains a short silver-iodide bond (Ag-I 2 · 703(1) Å). The silver-palladium bond is bridged by iodine (Pd-Ag 3 · 011(1), Pd{I 2 · 5934(9) Å) and the silver atom is coordinated by the tris-chelating oxygen ligand LOMe.

Reactivity of [NBu4][(C6F5)2M(μ-PPh2)2M‘(acac-O,O‘)] (M, M‘ = Pt, Pd) toward Silver Centers. Synthesis of Polynuclear Complexes Containing M−Ag Bonds (M = Pd, Pt)

“…The Pd−Ag distance observed in 2b is one of the shortest reported in the literature. Only a few polynuclear Pd/Ag complexes have been reported, but in most cases the Pd−Ag distances are longer than 3 Å, − and only in two cases are the Pd−Ag distances less than 2.9 Å: [Pd(H 2 O)LAg] 2+ (2.884(2) Å) 25 and [Mn 2 Pd 2 Ag(μ-Cl)(μ-PPh 2 ) 2 (μ-dppm)(CO) 8 ] (2.7259(6) and 2.8014(6) Å) . In the first case a presumably weak Pd−C(aryl)−Ag interaction is stabilized by peripheral coordination of the silver center to three oxygen atoms of the ligand, while in the Mn/Pd/Ag cluster the silver center is exclusively bonded to the four other metal centers.…”

Electrophilic Ruthenium(VI) Nitrido Complex Containing Kläui's Oxygen Tripodal Ligand

“…Potentials were reported with reference to the ferrocenium/ferrocene couple. Elemental analyses were performed by Medac Ltd., Surrey, U.K. [ n -Bu 4 N][Ru(N)Cl 4 ] and [AgL OEt ] were prepared according to literature methods. Ru(NO)Cl 3 · x H 2 O was purchased from Strem Ltd. and used as received.…”

Synthesis and Reactivity of the Neutral Pyrazolate Complexes [M2{CH2C6H4P(o-tolyl)2-κC,P}2(μ-Rpz)2] (M = Pd, Pt; Rpz = Pz, 3,5-dmpz, 4-Mepz) toward AgClO4. Molecular Structure of [Pt2Ag{CH2C6H4P(o-tolyl)2-κC,P}2(μ-4-Mepz)2]ClO4

“…A rich chemistry in this area has been developed in our group, involving the synthesis of heteronuclear Pt II −M compounds − (M = Ag, Cu, Hg, Tl, Pb, Sn), which have usually been obtained by reacting mono- or dinuclear anionic pentahalophenyl complexes of Pt II with the corresponding complexes or salts of the metal M. In some cases the neutral mono- or dinuclear platinum complexes have been used for preparing Pt→M derivatives. However, complexes containing Pd→M bonds usually cannot be prepared, except for a few cases in which very long Pd−Ag bonds (if any) are supported by bridging ligands. − In the case of (perhalophenyl)palladate substrates, similar Pd−Ag derivatives have not been obtained mainly due to trans-arylation processes 2,4 or to a reluctance of the Pd center to engage in the formation of this type of Pd→M donor−acceptor bond …”