Carbonyl-organocobalt(I) and -(II) complexes

Passage of CO through solutions of complexes (C₆F₅)₂CoL₂ gives carbonyl derivatives (C₆F₅)₂CoL₂(CO) (L₂ = 2 PEt₃, 2 P-n-Bu₃, 2 PPh₃, Ph₂PCH₂CH₃PPh₂). The properties of these compounds are described.The compounds are also produced by treating solutions of (C₆F₅)₂Co-(dioxane)₂ with CO, but a simultaneous reduction to (C₆F₅)Co(CO)₄ takes place. Treatment of the latter complex with monodentate ligands gives substitution products (C₆F₅)Co(CO)₃L (L = PEt₃, P-n-Bu₃, PPh₃) all of which are monomeric, whereas the addition of Ph₂PCH₂CH₂PPh₂ gives the dimer (C₆F₅)(CO)₂CoLLCo(CO)₂(C₆F₅). The properties of these compounds are discussed.     

Cationic pentafluorophenyl complexes of platinum(II)

The complex [O₃ClOPt(C₆F₅)(PEt₃)₂] which we have prepared for the first time, is used as a precursor of a series of cationic complexes [LPt(C₆F₅)(PEt₃)₂]ClO₄ (L = PEt₃, AsPh₃, H₂O, CO, OPPh₃, SPPh₃, HNPr₂, py), which are easily obtained by adding L to the perchlorato complex.     

Steric effects in oxidative addition and reductive elimination reactions of rhodium pentafluorophenylthiolate complexes

The complexes [cis-Rh(SC₆F₅)(PPh₃)₂(L)] (L = py, 3-Mepy, isoquin, N-Melm; py = pyridine, 3-Mepy = 3-methylpyridine, isoquin = isoquinoline, N-Melm = N-methylimidazole) readily undergo oxidative addition of HR (R = H, SC₆F₅, C₂Ph) to give [RhH(R)(SC₆F₅)(PPh₃)_n(L)_3−n] (n = 1, 2) whereas the complexes [cis-Rh(SC₆F₅)(PPh₃)₂(L′)] (L′ = 2-Mepy, 2,6-Me₂py, quin; 2-Mepy = 2-methylpyridine; 2,6-Me₂py = 2,6-dimethylpyridine, quin = quinoline) react only where R = C₂Ph. Where conditions favour the formation of [RhH(R)(SC₆F₅)(PPh₃)_n(L′)_3−n] reductive elimination of H₂ (R = H) or C₆F₅SH (R = SC₆F₅, C₂Ph) occurs.     

Cationic palladium(II) complexes involving unprecedented O-coordination of acetylmethylenetriphenylphosphorane

Cationic pentafluorophenyl palladium(II) complexes of the type [Pd(C₆F₅)L₂(APPY)]ClO₄ (L = PPh₃, PBu₃ⁿ; L₂ = bipy and A acetylmethylenetriphenylphosphorane) have been prepared by addition of APPY to the perchlorato complexes [Pd(OClO₃)(C₆F₅)L₂]; the APPY ligand is O-coordinated, which is unprecedented in keto-stabilized ylide complexes of palladium.The neutral complex Pd(C₆F₅)(Cl)(tht)(APPY) has been made by addition of APPY to the binuclear complex Pd₂(μ-Cl)₂(C₆F₅)₂(tht)₂ (tht = tetrahydrothiophene); in which the APPY ligand shows the normal C-coordination.     

Platinum derivatives of decafluorophosphorobenzene and decafluoroarsenobenzene. The crystal structure of Pt(PPh3)2 (PC6F5)2

The platinum complexes Pt(PPh₃)₂ (PC₆F₅)₂ and Pt(PPh₃)₂(AsC₆F₅)₂ have been isolated from reactions of Pt(PPh₃)₃ with (PC₆F₅)₄ and (AsC₆F₅)₄ respectively. A single-crystal X-ray analysis of Pt(PPh₃)₂(PC₆F₅)₂ has shown that the compound crystallizes in space group P2₁ with a = 9.286(5), b = 20.95(1), c = 11.226(5) Å, β = 90.7(1)°, Z = 2. The structure has been solved by Patterson and Fourier methods and refined to R = 0.043 from three-dimensional diffractometer data. The complex contains the decafluorophosphorobenzene unit C₆F₅PPC₆F₅ bound through each P atom to the platinum. Coordination around the platinum is distorted square planar; the dihedral angle between the two PtP₂ planes is 20.4°.     

Binuclear hydroxo-monopentahalophenyl complexes of palladium(II)

The novel binuclear hydroxo-bridged complexes trans-[R(PPh₃)Pd(μ-OH)₂Pd(PPh₃)R] and cis-[R(PPh₃)Pd(μ-OH)(μ-pz)Pd(PPh₃)R] (R = C₆F₅ or C₆Cl₅; pz = pyrazolate) have been prepared, and their structures assigned on the basis of NMR data.     

The preparation of cis- and trans-[PtH(C6Cl5)(PEt3)2 and a study of the “hydride-donor capacity” of the complexes trans- [PtH(C6X5(PEt3)2] (X = F and Cl)

The preparations of cis- and trans-[PtH(C₆Cl₅)(PEt₃)₂] by thermal decomposition of cis- and trans-[Pt(OCHO)(C₆Cl₅)(PEt₃)₂], respectively, are reported. Also described are cis- and trans-[Pt(SnCl₃)(C₆Cl₅)(PEt₃)₂], obtained by treating SnCl₂ with cis- and trans-[PtCl(C₆,Cl₅)(PEt₃)₂], respectively. It is shown that while trans- [PtH(C₆Cl₅)(PEt₃)₂] does not form hydride-bridged complexes in the presence of trans-(PtH(MeOH)(PEt₃)₂]⁺, the corresponding complex trans-[PtH(C₆)(PEt₃)₂] reacts with the same solvento complex, in methanol, giving labile [(PEt₃)₂HPt(-μH)Pt(C₆F₅)(PEt₃)₂]⁺.     

Preparation and characterization of mono-cyclopentadienylvanadium dihalide bis-phosphine complexes; crystal structure of (η5-C5H5)VCL2(PMe3)2

Mono-cyclopentadienyl complexes CpVX₂(PR₃)₂ and Cp′VX₂ (PR₃)₂ (Cp = η⁵- C₅H₅; Cp′ = η⁵-C₅H₄Me; R = Me, Et; X = Cl, Br) have been prepared by reaction of VX₃(PR₃)₂ with CpM (M = Na, T1, SnBuⁿ3, 1/2 Mg) or Cp′Na. Attempts to prepare analogous complexes with other phosphine ligands, PPh₃, PPh₂ Me, PPhMe₂, Pcy₃, DMPE and DPPE failed. Reduction of CpVCl₂(PEt₃)₂ with zinc or aluminium under CO (1 bar) offers a simple method for the preparation of CpV(CO)₃(PEt₃). The crystal structure of the trimethylphosphine complex CpVCl₂(PMe₃)₂ is reported.     

Polynuclear palladium and gold perhalophenyl derivatives with dppm bridges. Crystal and molecular structure of trans-C6F5Au(μ-dppm)Pd(C6F5)2(μ-dppm)AuC6F5 (dppm = Ph2PCH2PPh2)

Reactions of PdRR′(η¹-dppm)₂ (R = R′= C₆F₅ or C₆Cl₅; R = C₆F₅, R′= Cl; dppm = Ph₂PCH₂PPh₂) with the gold derivatives ClAu(tht), C₆F₅Au(tht), (C₆F₅)₃Au(tht) or O₃ClOAuPPh₃ (tht = tetrahydrothiophen) in appropriate ratios yield the bi- or tri-nuclear complexes PdRR′(dppm)₂AuCl, PdRR′(dppm)₂Au(C₆F₅); PdRR′(dppm)₂Au(C₆F₅)₃; PdRR′(dppmAuCl)₂; PdRR′(dppmAuC₆F₅)₂; PdRR′[dppmAu(C₆F₅)₃]₂, [PdRR′(dppm)₂Au]X (X = ClO₄ or BPh₄); [PPh₃Au(dppm)Pd(C₆F₅)₂(dppm)AuCl]ClO₄ or [PPh₃ Au(dppm)Pd(C₆F₅)₂(dppm)Au(C₆F₅)₃]ClO₄. The structure of trans-Pd(C₆F₅)₂[dppmAu(C₆F₅)]₂ has been determined by X-ray diffraction.     

Aryl- and acetylene-nickel(I) complexes

Reduction of various pentafluorophenylnickel(II) complexes in the presence of phosphines gives unstable nickel(I) compounds but Ni(C₆F₅)(CO)₂(PPh₃)₂ is isolated in the presence of CO. Similar NiR(CO)₂(PPh₃)₂ (R = C₆F₅,C₆Cl₅, 2,3,5,6-C₆Cl₄H) are obtained by reaction of the halogenonickel(I) complex with MgRBr or LiR. Reduction of NiX₂L₂ in the presence of acetylenes gives [NiXL₂]₂(μ-PhCCR) (R = H, X = Cl and R = Ph, X = Cl, Br) when L = P-n-Bu₃ but only NiX(PPh₃)₃ are recovered when L = PPh₃. No reaction with the alkyne is observed for [NiX(PPh₃)₂]_n but [NiCl(PPh₃)]_n reacts with RCCR′ to give paramagnetic NiCl(PPh₃)(CRCR′) (R = Ph, R′= H, COOEt), diamagnetic [NiCl(PPh₃)]₂(μ-PhCCPh) and cyclotrimerization when R = R′ = COOMe. Chemical and structural behaviour of the new nickel(I) complexes is described.     

Perhalophenyl complexes of palladium(II) containing keto-stabilized phosphorus ylides of the type Ph2P(CH2)nPPh2CHC(O)R

From suitable perhalophenyl derivatives of palladium(II), viz.: Pd(C₆F₅)₂-(SC₄H₈)₂, [Pd(μ-X′) (C₆X₅)₂]₂(NBu₄)₂, [Pd(μ-Cl)(C₆X₅)(SC₄H₈)]₂ (X = F, Cl, X′ = Cl, Br), new complexes of various types have been prepared, viz.: trans-Pd(C₆F₅)₂(Y)₂, Pd(C₆X₅)₂(Y), PdCl(C₆X₅)(Y) (X = F, Cl). The neutral ligand Y is a keto-stabilized phosphorus ylide of the type Ph₂P(CH₂)_nPPh₂CHC(O)R (n = 1, R = CH₃, C₆H₅; n = 2, R = C₆H₅) acting in a terminal monodentate P-donor or a bidentate chelate P,C-donor mode. The reaction of PdCl(C₆F₅)(Y) complexes with HCl leads to the corresponding PdCl₂(C₆F₅)(YH) complexes in which the phosphonium cation [YH]⁺ behaves as monodentate P-donor at its phosphinic end.IR and ³¹P NMR spectroscopy were used to decide the coordination mode of the ligands and, in some cases, to reveal the presence of two isomers.     

New nitrosyl(perfluorocarboxylato) complexes of the platinum metals

Perfluorocarboxylic acids (R_FCOOH) (R_F = CF₃,C₂F₅ and (for Rh) C₆F₅) react with the species [M(NO)₂(PPh₃)₂] (M = Ru, Os) and [M′(NO)(PPh₃)₃] (M′ = Rh, Ir) to yield new nitrosyl complexes [Ru(OCOR_F)₃(NO)(PPh₃)₂], [OsH(OCOR_F)₂(NO)(PPh₃)₂], [Os(OCOR_F)(NO)₂(PPh₃)₂][OCOR_F], [Ir(OCOR_F)(NO)(PPh₃)₂][OCOR_F] and [Rh(OCOR_F)₂(NO)(PPh₃)₂].     

Strukturen von neuen Bis(pentafluorophenyl)halogenomercuraten [{Hg(C6F5)2}3(μ‐X)]— (X = Cl,Br, I)

Structures of New Bis(pentafluorophenyl)halogeno Mercurates [{Hg(C₆F₅)₂}₃(μ‐X)]^— (X = Cl, Br, I) From the reactions of [PNP]Cl or [PPh₄]Y (Y = Br, I) with Hg(C₆F₅)₂ crystals of the composition [Cat][{Hg(C₆F₅)₂}₃X] (Cat = PNP, X = Cl ( 1 ); Cat = PPh₄, X = Br ( 2 ), I ( 3 )) are formed. 1 crystallizes in the triclinic space group P1¯, 2 and 3 crystallize isotypically in the monoclinic space group C2/c. In the crystals the halide anions are surrounded by three Hg(C₆F₅)₂ molecules. The reaction of [PPh₄]Br with Hg(C₆F₅)₂ under slightly changed conditions gives the compound [PPh₄]₂[{Hg(C₆F₅)₂}₃(μ‐Br)][{Hg(C₆F₅)₂}₂(μ‐Br)] ( 4 ).     

Synthesis and characterization of new sulfide aggregates of the type [{Pt2(μ3-S)2(P-P)2}M(C6F5)2] (M=Ni, Pd, Pt; P-P=2PPh3, 2PMe2Ph, dppf)

The reaction of [Pt₂(μ-S)₂(P-P)₂] (P-P=2PPh₃, 2PMe₂Ph, dppf) [dppf=1,1^′-bis(diphenylphosphino)ferrocene] with cis-[M(C₆F₅)₂(PhCN)₂] (M=Ni, Pd) or cis-[Pt(C₆F₅)₂(THF)₂] (THF=tetrahydrofuran) afforded sulfide aggregates of the type [{Pt₂(μ₃-S)₂(P-P)₂}M(C₆F₅)₂] (M=Ni, Pd, Pt). X-ray crystal analysis revealed that [{Pt₂(μ₃-S)₂(dppf)₂}Pd(C₆F₅)₂], [{Pt₂(μ₃-S)₂(PPh₃)₂}Ni(C₆F₅)₂], [{Pt₂(μ₃-S)₂(PPh₃)₂}Pd(C₆F₅)₂] and [{Pt₂(μ₃-S)₂(PMe₂Ph)₂}Pt(C₆F₅)₂] have triangular M₃S₂ core structures capped on both sides by μ₃-sulfido ligands. The structural features of these polymetallic complexes are described. Some of them display short metal-metal contacts.     

Decarboxylation syntheses of transition metal organometallics,II.trans-carbonyl(polyhalogenophenyl)bis(triphenylphosphine)rhodium(I) compounds

Summary The rhodium(I) carboxylates,trans-RhO₂CR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,o-HC₆F₄,p-McOC₆F₄, 4,5-H₂C₆F₃, 3,5-H₂C₆F₃, or 2,6-F₂C₆H₃, have been prepared by reaction of RhH(CO)(PPh₃)₃ with the appropriate polyhalogenobenzoic acids in ethanol and/or by reaction oftrans-RhCl(CO)(PPh₃)₂ with the appropriate thallous carboxylates in benzene. Decarboxylations with formation of polyhalogenoarylrhodium(I) compounds,trans-RhR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,p-MeOC₆F₄, 4,5-H₂C₆F₃ or 3,5-H₂C₆F₃), have been achieved either by decomposition of the corresponding rhodium(I) carboxylates in pyridine or by reaction oftrans-RhCl(CO)(PPh₃)₂ and the thallous carboxylates in pyridine, but the derivatives R =o-HC₆F₄ or 2,6-F₂C₆H₃ could not be obtained by this method. The rate of decarboxylation decreased in the sequence R = C₆F₅ >p-MeOC₆F₄ >p-HC₆F₄ >m-HC₆F₄ > 4,5-H₂C₆F₃ > 3,5-H₂C₆F₃.Part 1, ref. 10.Preliminary communication, ref. 9.     

A new class of polymeric complexes having Pt-Ag interactions: Crystal structure of |{[(PPh3)(C6F5)Pt(μ-Cl)]2Ag}(μ-Cl)2Ag(MeOH)|n

The reaction of (NBu₄)[trans-PtCl₂(C₆F₅)L] (L = PPh₃, AsPh₃) with AgClO₄ (1:1) molar ratio in a CH₂Cl₂/MeOH mixture leads to the polymeric complexes [PtAgCl₂(C₆F₅)L]_n (L = PPh₃1, AsPh₃2). The structure of complex |{[(PPh₃)(C₆F₅)Pt(μ-Cl)]₂Ag}(μ-Cl)₂Ag(MeOH)|_n (1·MeOH) has been determined by single-crystal X-ray diffraction, showing a chain polymer in which the silver atoms are in two different environments with or without Pt-Ag bond.     

Synthesis of ylideplatinum(II) complexes via α-functionalised alkylplatinum(II) intermediates and some comparative data on palladium(II) complexes; X-ray structure of trans-[Pt(CH2PEt3)I(PEt3)2]I

The reaction of [Pt(PEt₃)₃] with CH₂I₂ affords trans-[Pt(CH₂PEt₃)I(PEt₃)₂]I and is believed to proceed via the α-functionalised alkyl cis-[Pt(CH₂I)I(PEt₃)₂], because similar ylides are obtained from cis- or trans-[PT(CH₂X)(PPh₃)₂X] (XCl, Br, or I) with PR₃ (PEt₃, PBu₃ⁿ, PMePh₂, PEtPh₂, or PPh₃); cis-[Pd(CH₂I)-I(PPh₃)₂] does not react with excess PPh₃, but with PEt₃ yields trans-[Pd(CH₂PEt₃)I(PPh₃)₂]I; the X-ray structure of trans-[Pt(CH₂PEt₃)I(PEt₃)₂]I (current R = 0.045) shows PtP(1) 2.332(7), PtP(2) 2.341(8), PtC 2.08(2), and PtI 2.666(2) Å, and angles (a) C(1)PtI, P(1), P(2): 176.9(8), 91.6(6), 93.4(6), (b) IPtP(1), P(2): 87.1(2), 88.5(2), and (c) P(1)P(2), 166.8(3), and (d) PtC(1)P(3), 118(1)°.     

Synthesis and 197Au-Mössbauer spectroscopic studies of dihalo(pentafluorophenyl)(bidentate ligand)gold(III) complexes

Addition of a bidentate ligand (LL = 1,10-phenanthroline, o-phenylenebis(dimethylarsine)) to solutions of Au(C₆F₅)X₂(tht) (X = Cl, Br; tht = tetrahydrothiophene) leads to potentially five-coordinate gold(III) derivatives. ¹⁹⁷Au Mössbauer spectroscopy points, however, to four-coordinate square-planar complexes with a weak penta-coordination in the phen-containing derivatives. The complexes react with AgClO₄ to give four-coordinate cationic complexes of the types [Au(C₅F₅)X(LL)]ClO₄ or [Au(C₆F₅)(PPh₃)(LL)](ClO₄)₂.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.     

NMR,IR and DFT studies of phenylplatinum complexes with O-monodentate coordinated silsesquioxanate and auxiliary phosphine ligands

The molecular structure and spectroscopic properties of a series of phenylplatinum complexes containing silsesquioxanate and phosphine ligands with general formula trans-[Pt{O₁₀Si₇(R)₇(OH)₂}(Ph)(L)₂] (1: R = cyclo-C₅H₉, L = PEt₃; 2: R = iso-C₄H₉, L = PEt₃; 3: R = CH₃, L = PEt₃; 4: R = cyclo-C₅H₉, L = PMe₃; 5: R = cyclo-C₅H₉, L = PMe₂Ph; 6: R = cyclo-C₅H₉, L = PPh₂Me; 7: R = cyclo-C₅H₉, L = PPh₃) have been investigated by DFT/OPW91/6-31G(d) calculations, ¹H, ¹³C, ²⁹Si and ³¹P NMR and IR spectroscopy. DFT molecular modeling based on available X-ray and NMR data for complexes 1 and 2 allowed deriving structure-NMR spectra correlations. It was found that the alkyl substituents (R) attached to Si atoms, cyclo-C₅H₉, iso-C₄H₉ and CH₃, slightly influence the geometry and multinuclear NMR parameters of the complexes in the series studied. The molecular structures of the Pt(II) complexes with R = cyclo-C₅H₉ (4–7) were predicted by DFT calculations of their simplified models with R = CH₃ (4′?7′). The geometry optimizations of 4′?7′ showed square-planar configuration of Pt(II) center bonded to two trans phosphine ligands, a phenyl group and an O-monocoordinated silsesquioxanate. The structures 4′?6′ are stabilized by two intramolecular hydrogen bonds similar to 1 and 2. A fast conformer exchange process A?B and switching of H-bonds in solution of 1–6 were suggested based on (i) the calculated conformer energies and small barrier of the process, and (ii) the observed single ¹H NMR signal at low magnetic field. The stability of the Pt(II) complexes depends on the nature of the phosphine ligands and decreases in the order PMe₂Ph > PMe₃ > PPh₂Me > PEt₃ > PPh₃. The PPh₃ ligands attached to Pt(II) in 7 cause the largest geometry changes and a new set of weaker hydrogen bonds. The comparison of the calculated NMR and IR parameters with the experimental spectroscopic data reveals good coincidence and thus confirmed the suggested molecular structures.