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]⁺.     

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.     

Versatile Reaction Pathways of 1,1,3,3,3-Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt3)3] (E=H,GePh3, Si(OEt)3, F,Cl): C-F versus C-H Bond Activation Steps

The reaction of the rhodium(I) complexes [Rh(E)(PEt₃)₃] (E=GePh₃ ( 1 ), H ( 6 ), F ( 7 )) with 1,1,3,3,3-pentafluoropropene afforded the defluorinative germylation products Z/E-2-(triphenylgermyl)-1,3,3,3-tetrafluoropropene and the fluorido complex [Rh(F)(CF₃CHCF₂)(PEt₃)₂] ( 2 ) together with the fluorophosphorane E-(CF₃)CH=CF(PFEt₃). For [Rh(Si(OEt)₃)(PEt₃)₃] ( 4 ) the coordination of the fluoroolefin was found to give [Rh{Si(OEt)₃}(CF₃CHCF₂)(PEt₃)₂] ( 5 ). Two equivalents of complex 2 reacted further by C−F bond oxidative addition to yield [Rh(CF=CHCF₃)(PEt₃)₂(μ-F)₃Rh(CF₃CHCF₂)(PEt₃)] ( 9 ). The role of the fluorido ligand on the reactivity of complex 2 was assessed by comparison with the analogous chlorido complex. The use of complexes 1 , 4 and 6 as catalysts for the derivatization of 1,1,3,3,3-pentafluoropropene provided products, which were generated by hydrodefluorination, hydrometallation and germylation reactions.     

Organoplumbio complexes of platinum(II)

The complex [Pt(C₂H₄)(PPh₃)₂] reacts with Pb₂Ph₆ to give cis-[PtPh(Pb₂Ph₅)(PPh₃)₂]; this decomposes in solution to cis-[PtPh(PbPh₃)(PPh₃)₂], which may also be obtained from the ethylene complex and PbPh₄. Lead compounds PbPhMe₃ and PbPh₃Br also give products of insertion into PbPh bonds, but PbMe₃Cl gives cis- and trans-[PtCl(PbMe₃)(PPh₃)₂]. The complex trans-[Pt(PbPh₃)₂(PEt₃)₂] reacts with 1,2-bis(diphenylphosphino)ethane (DPPE) to give [Pt(PbPh₃)₂(DPPE)] which readily decomposes in dichloromethane in presence of PEt₃ to give [Pt(PbPh₃)(PEt₃)(DPPE)]Cl and [PtPh(PEt₃)(DPPE)]Cl. The complex trans-[PtCl(PbPh₃)(PEt₃)₂] was detected in the products of reactions between trans-[PtCl₂(PEt₃)₂] and trans-[Pt(PbPh₃)₂(PEt₃)₂] or less than 2 moles of LiPbPh₃; it was not detected in the mixture after treatment of trans -[Pt(PbPh₃)₂(PEt₃)₂] with HCl. In contrast to an earlier report, we were unable to detect lead-containing complexes in the products of the reaction between trans-[PtHCl(PPh₃)₂] and Ph₃PbNO₃. The complexes and their decomposition products were identified by ^pre31P-{¹H} NMR spectroscopy.     

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.     

Synthesis and structures of new binuclear zinc alkyl,aryl and aryloxo complexes

The synthesis of a series of binuclear zinc complexes with Cl, N and O bridges is reported. The reaction of EtZnCl with B(C₆F₅)₃ in the presence of hexamethylbenzene affords the arene complex [Zn(μ-Cl)(C₆F₅)(η-C₆Me₆)]₂ in which the C₆Me₆ ligand may be regarded as η³-bonded. The comproportionation of Zn[N(SiMe₃)₂]₂ with ZnBu^t₂ or Zn(C₆F₅)₂ · toluene gave [Bu^tZn{μ-N(SiMe₃)₂}]₂ and [C₆F₅Zn{μ-N(SiMe₃)₂}]₂, respectively, with three-coordinate zinc. The reaction of ZnEt₂ with C₆F₅OH in the presence of pyridine gave [EtZn(μ-OC₆F₅)(py)]₂, while ZnMe₂ and C₆F₅OH followed by recrystallisation from THF gave [Zn(OC₆F₅)(μ-OC₆F₅)(THF)₂]₂ with five-coordinate zinc in a trigonal-bipyramidal geometry. The structures of these compounds have been determined.     

New η-allyl η-cyclopentadienylcobalt cations

[Co(R-η-C₃H₄)(η-C₅H₅)I] is a good precursor for the preparation of some new cationic complexes as the iodide can easily be replaced; thus addition of PEt₃ to the iodo-complex (R  H) gives [Co(η-C₃H₅)(η-C₅H₅)(PEt₃)]⁺. The reactions of [Co(R-η-C₃H₄)(η-C₅H₅))I] (R  H or 2-Me) with AgBF₄ give solutions containing the coordinatively unsaturated species [Co(R-η-C₃H₄)(η-C₅H₅)⁺. The presence of traces of water leads to the formation of [Co(R-ηC₃H₄)-(η-C₅H₅)(H₂O)]⁺. The addition of monodentate ligands L  PEt₃ PPh₃, AsPh₃, SbPh₃, CNCH₃ and bidentate ligands LL  Ph₂PCH₂CH₂PPh₂(dppe) and o-C₆H₄(AsMe₂)₂(diars), gives, respectively mononuclear [Co(2-Me-ηC₃H₄)-(η-C₅H₅)L]⁺ and binuclear ligand-bridged [(2-Me-ηC₃H₄)(η-C₅H₅)CoLLCo(2-Me-ηC₃H₄)(η-C₅H₅))]²⁺ complexes. Crystals of [Co(2-Me-ηC₃H₄)(η-C₅H₅)-(H₂O)]⁺[BF₄]^- are monoclinic, space group P2₁/c, with a 7.858(3), b 10.262(4), c 15.078(4) Å, β 98.36(1)°. The molecular structure contains the cobalt atom bonded to planar 2-Me-allyl and cyclopentadienyl substituents, which are almost parallel with the H₂O molecule in a staggered conformation with respect to the 2-Me group.     

Titanium(IV) Cations with Trigonal Monopyramidal Geometry: Unusual Lewis Acids Supported by a Triaryl Triamidoamine Ligand

Protonolysis of the titanium alkyl complex [Ti(CH₂SiMe₃)(Xy-N₃N)] (Xy-N₃N=[{(3,5-Me₂C₆H₃)NCH₂CH₂}₃N]³⁻) supported by a triamidoamine ligand, with [NEt₃H][B(3,5-Cl₂C₆H₃)₄] or [PhNMe₂H][B(C₆F₅)₄] afforded the cations [Ti(Xy-N₃N)][A] (A⁻=[B(3,5-Cl₂C₆H₃)₄]⁻ ( 1[B(Ar^Cl)₄] ; B(Ar^Cl)₄=tetrakis(3,5-dichlorophenyl)borate); A⁻=[B(C₆F₅)₄]⁻ ( 1[B(Ar^F)₄] ; B(Ar^F)₄=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate). These Lewis acidic cations were reacted with coordinating solvents to afford the cations [Ti(L)(Xy-N₃N)][B(C₆F₅)₄] ( 2-L ; L=Et₂O, pyridine and THF). XRD analysis revealed a trigonal monopyramidal (TMP) geometry for the tetracoordinate cations in 1[B(Ar^X)₄] and trigonal bipyramidal (TBP) geometry for the pentacoordinate cations in 2-L . Variable-temperature NMR spectroscopy showed a dynamic equilibrium for 2-Et₂O in solution, involving the dissociation of Et₂O. Coordination to the titanium(IV) center activated the THF molecule, which, in the presence of NEt₃, underwent ring-opening to give the titanium alkoxide [Ti(O(CH₂)₄NEt₃)(Xy-N₃N)][B(3,5-Cl₂C₆H₃)₄] ( 3 ). Hydride abstraction from C_β,eq of the triamidoamine ligand arm in [Ti(CH₂SiMe₃)(Xy-N₃N)] or [Ti(NMe₂)(Xy-N₃N)] with [Ph₃C][B(3,5-Cl₂C₆H₃)₄] led to the diamidoamine–imine complex [Ti(R){(Xy-N=CHCH₂)(Xy-NCH₂CH₂)₂N}][B(3,5-Cl₂C₆H₃)₄] (R=CH₂SiMe₃ ( 4 a ); R=NMe₂ ( 4 b )). Hydride addition to 4 b with [Li(THF)][HBPh₃] gave [Ti(NMe₂)(Xy-N₃N)], whereas KH deprotonated further to give [Ti(NMe₂){(Xy-NCH=CH)(Xy-NCH₂CH₂)₂N}] ( 5 ). XRD on single crystals of 3 and 4 b confirmed the proposed structures.     

Coordination Properties of Perfluoroethyl‐ and Perfluorophenyl‐Substituted Phosphonous acids,RfP(OH)2

Phosphinic acids, R^fP(O)(OH)H (R^f=CF₃, C₂F₅, C₆F₅), turned out to be excellent preligands for the coordination of phosphonous acids, R^fP(OH)₂. Addition of C₂F₅P(O)(OH)H to solid PtCl₂ under different reaction conditions allows the isolation and full characterization of the mononuclear complexes [ClPt{P(C₂F₅)(OH)O}{P(C₂F₅)(OH)₂}₂] and [Pt{P(C₂F₅)(OH)O}₂{P(C₂F₅)(OH)₂}] containing hydrogen‐bridged [R^fP(OH)O]^? and R^fP(OH)₂ units. Further deprotonation of [Pt{P(C₂F₅)(OH)O}₂{P(C₂F₅)(OH)₂}₂] leads to the formation of the dianionic platinate, [Pt{P(C₂F₅)(OH)O}₄]^2?, revealing four intramolecular hydrogen bridges. With PdCl₂ the dinuclear complex [Pd₂(μ‐Cl)₂{[P(C₂F₅)(OH)O]₂H}₂] was isolated and characterized. The Cl^? free complex [Pd{P(C₂F₅)(OH)O}₂{P(C₂F₅)(OH)₂}₂] was also prepared and deprotonated to the dianionic palladate, [Pd{P(C₂F₅)(OH)O}₄]^2?. Both compounds were characterized by NMR spectroscopy, IR spectroscopy, and X‐ray analyses. In addition, the C₆F₅ derivatives [ClPt{P(C₆F₅)(OH)O}{P(C₆F₅)(OH)₂}₂] and [Pd₂(μ‐Cl)₂{[P(C₆F₅)(OH)O]₂H}₂] as well as the CF₃ derivative [Pd₂(μ‐Cl)₂{[P(CF₃)(OH)O]₂H}₂] were synthesized and fully characterized. Phosphonous acid complexes are inert towards air and moisture and can be stored for several months without decomposition. The catalytic activity of the palladium complexes in the Suzuki cross‐coupling reaction between 1‐bromo‐3‐fluorobenzene and phenyl boronic acid was demonstrated.     

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.     

Synthesis and Reactivity of Boron‐, Silicon‐, and Tin‐Bridged ansa‐Cyclopentadienyl–Cycloheptatrienyl Titanium Complexes (Troticenophanes)

A novel one‐pot method was developed for the preparation of [Ti(η⁵‐C₅H₅)(η⁷‐C₇H₇)] (troticene, 1 ) by reaction of sodium cyclopentadienide (NaCp) with [TiCl₄(thf)₂], followed by reduction of the intermediate [(η⁵‐C₅H₅)₂TiCl₂] with magnesium in the presence of cycloheptatriene (C₇H₈). The [n]troticenophanes 3 (n=1), 4 , 8 , 10 (n=2), and 11 (n=3) were synthesized by salt elimination reactions between dilithiated troticene, [Ti(η⁵‐C₅H₄Li)(η⁷‐C₇H₆Li)] ? pmdta ( 2 ) (pmdta=N,N′,N′,N′′,N′′‐pentamethyldiethylenetriamine), and the appropriate organoelement dichlorides Cl₂Sn(Mes)₂ (Mes=2,4,6‐trimethylphenyl), Cl₂Sn₂(tBu)₄, Cl₂B₂(NMe₂)₂, Cl₂Si₂Me₄, and (ClSiMe₂)₂CH₂, respectively. Their structural characterization was carried out by single‐crystal X‐ray diffraction and multinuclear NMR spectroscopy. The stanna[1]‐ and stanna[2]troticenophanes 3 and 4 represent the first heteroleptic sandwich complexes bearing Sn atoms in the ansa bridge. The reaction of 3 with [Pt(PEt₃)₃] resulted in regioselective insertion of the [Pt(PEt₃)₂] fragment into the Sn? C_ipso bond between the tin atom and the seven‐membered ring, which afforded the platinastanna[2]troticenophane 5 . Oxidative addition was also observed upon treatment of 4 with elemental sulfur or selenium, to produce the [3]troticenophanes [Ti(η⁵‐C₅H₄SntBu₂)(η⁷‐C₇H₆SntBu₂)E] ( 6 : E=S; 7 : E=Se). The B? B bond of the bora[2]troticenophane 8 was readily cleaved by reaction with [Pt(PEt₃)₃] to form the corresponding oxidative addition product [Ti(η⁵‐C₅H₄BNMe₂)(η⁷‐C₇H₆BNMe₂)Pt(PEt₃)₂] ( 9 ). The solid‐state structures of compounds 5 , 6 , and 9 were also determined by single‐crystal X‐ray diffraction.     

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].     

One- and Two-Electron Transfer Oxidation of 1,4-Disilabenzene with Formation of Stable Radical Cations and Dications

Electron-transferable oxidants such as B(C₆F₅)₃/nBuLi, B(C₆F₅)₃/LiB(C₆F₅)₄, B(C₆F₅)₃/LiHBEt₃, Al(C₆F₅)₃/(o-RC₆H₄)AlH₂ (R=N(CMe₂CH₂)₂CH₂), B(C₆F₅)₃/AlEt₃, Al(C₆F₅)₃, Al(C₆F₅)₃/nBuLi, Al(C₆F₅)₃/AlMe₃, (CuC₆F₅)₄, and Ag₂SO₄, respectively were employed for reactions with (L)₂Si₂C₄(SiMe₃)₂(C₂SiMe₃)₂ (L=PhC(NtBu)₂, 1 ). The stable radical cation [ 1 ]^+. was formed and paired with the anions [nBuB(C₆F₅)₃]⁻ (in 2 ), [B(C₆F₅)₄]⁻ (in 3 ), [HB(C₆F₅)₃]⁻ (in 4 ), [EtB(C₆F₅)₃]⁻ (in 5 ), {[(C₆F₅)₃Al]₂(μ-F)]⁻ (in 6 ), [nBuAl(C₆F₅)₃]⁻ (in 7 ), and [Cu(C₆F₅)₂]⁻ (in 8 ), respectively. The stable dication [ 1 ]²⁺ was also generated with the anions [EtB(C₆F₅)₃]⁻ ( 9 ) and [MeAl(C₆F₅)₃]⁻ ( 10 ), respectively. In addition, the neutral compound [(L)₂Si₂C₄(SiMe₃)₂(C₂SiMe₃)₂][μ-O₂S(O)₂] ( 11 ) was obtained. Compounds 2 – 11 are characterized by UV-vis absorption spectroscopy, X-ray crystallography, and elemental analysis. Compounds 2 – 8 are analyzed by EPR spectroscopy and compounds 9 – 11 by NMR spectroscopy. The structure features are discussed on the central Si₂C₄-rings of 1 , [ 1 ]^+., [ 1 ]²⁺, and 11 , respectively.     

Ansa‐Complexes of [Mn(η5‐C5H5)(η6‐C6H6)]: Preparation,Characterization, and Reactivity of [n]Manganoarenophanes (n=1, 2, 3)

We report the synthesis of [n]manganoarenophanes (n=1, 2) featuring boron, silicon, germanium, and tin as ansa‐bridging elements. Their preparation was achieved by salt‐elimination reactions of the dilithiated precursor [Mn(η⁵‐C₅H₄Li)(η⁶‐C₆H₅Li)]?pmdta (pmdta=N,N,N′,N′,N′′‐pentamethyldiethylenetriamine) with corresponding element dichlorides. Besides characterization by multinuclear NMR spectroscopy and elemental analysis, the identity of two single‐atom‐bridged derivatives, [Mn(η⁵‐C₅H₄)(η⁶‐C₆H₅)SntBu₂] and [Mn(η⁵‐C₅H₄)(η⁶‐C₆H₅)SiPh₂], could also be determined by X‐ray structural analysis. We investigated for the first time the reactivity of these ansa‐cyclopentadienyl–benzene manganese compounds. The reaction of the distannyl‐bridged complex [Mn(η⁵‐C₅H₄)(η⁶‐C₆H₅)Sn₂tBu₄] with elemental sulfur was shown to proceed through the expected oxidative addition of the Sn?Sn bond to give a triatomic ansa‐bridge. The investigation of the ring‐opening polymerization (ROP) capability of [Mn(η⁵‐C₅H₄)(η⁶‐C₆H₅)SntBu₂] with [Pt(PEt₃)₃] showed that an unexpected, unselective insertion into the C_ipso?Sn bonds of [Mn(η⁵‐C₅H₄)(η⁶‐C₆H₅)SntBu₂] had occurred.     

Synthetic and spectroscopic studies of some mono-hydrido-bridged complexes of platinum(II)

The mono-hydrido-bridged complexes (PEt₃)₂(Ar)Pt(μ₂-H)Pt(Ar)(PEt₃)₂]-[BPh₄] (Ar = Ph, 4-MeC₆H₄ and 2,4-Me₂C₆H₃) have been obtained by treating trans-[Pt(Ar)(MeOH)(PEt₃)₂][BF₄] with sodium formate and Na[BPH₄]. The cations [PEt₃)₂(Ar)Pt(μ₂-H)Pt(Ar^b')(PEt₃)₂]^b+ (Ar = Ph and Ar^b' - 2,4-Me₂C₆H₃ and 2,4,6-Me₃C₆H₂ have bee identified in solution. Their ^b1H- and ^b31P-NMR data are reported. The X-ray crystal structure of [(PEt₃)₂(Ph)Pt(μ₂-H)Pt(Ph)(PEt₃)₂][BPh₄] is reported.     

Synthesis and Reactivity of Iridium(I) Fluorido Complexes: Oxidative Addition of SF4 at trans-[Ir(F)(CO)(PEt3)2]

The facile access to the Vaska type fluorido complexes trans-[Ir(F)(CO)(PR₃)₂] [ 6 : R = Et, 7 : R = Ph, 8 : R = iPr, 9 : R = Cy, 10 : R = tBu] was achieved by halide exchange at trans-[Ir(Cl)(CO)(PR₃)₂] ( 1 – 5 ) with Me₄NF. Furthermore, the reaction of complex 6 with SF₄ gave cis,trans-[Ir(F)₂(SF₃)(CO)(PEt₃)₂] ( 11 ), whereas 8 – 10 did not react. Reactivity studies revealed that 11 can selectively be manipulated at the sulfur atom by hydrolysis or fluoride abstraction to give cis,trans-[Ir(F)₂(SOF)(CO)(PEt₃)₂] ( 12 ) and cis,trans-[Ir(F)₂(SF₂)(CO)(PEt₃)₂][AsF₆] ( 13 ), respectively.     

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.     

Iridium(I)‐ und Iridium(III)‐Komplexe mit Triisopropylarsan als Ligand

Iridium(I) and Iridium(III) Complexes with Triisopropylarsane as Ligand The ethene complex trans‐[IrCl(C₂H₄)(AsiPr₃)₂] ( 2 ), which was prepared from [IrCl(C₂H₄)₂]₂ and AsiPr₃, reacted with CO and Ph₂CN₂ by displacement of ethene to yield the substitution products trans‐[IrCl(L)(AsiPr₃)₂] ( 3 : L = CO; 4 : L = N₂). UV irradiation of 2 in the presence of acetonitrile gave via intramolecular oxidative addition the hydrido(vinyl)iridium(III) compound [IrHCl(CH=CH₂)(CH₃CN)(AsiPr₃)₂] ( 5 ). The reaction of 2 with dihydrogen led under argon to the formation of the octahedral complex [IrH₂Cl(C₂H₄)(AsiPr₃)₂] ( 7 ), whereas from 2 under 1 bar H₂ the ethene‐free compound [IrH₂Cl(AsiPr₃)₂] ( 6 ) was generated. Complex 6 reacted with ethene to afford 7 and with pyridine to give [IrH₂Cl(py)(AsiPr₃)₂] ( 8 ). The mixed arsane(phosphane)iridium(I) compound [IrCl(C₂H₄)(PiPr₃)(AsiPr₃)] ( 11 ) was prepared either from the dinuclear complex [IrCl(C₂H₄)(PiPr₃)]2 ( 9 ) and AsiPr₃ or by ligand exchange from [IrCl(C₂H₄)(PiPr₃)(SbiPr₃)] ( 10 ) und triisopropylarsane. The molecular structure of 5 was determined by X‐ray crystallography.     

Reactions involving transition metals : XIX. Some reactions of perfluoronorbornadiene with low valent transition metal complexes

Perfluoronorbornadiene reacts with the compounds [M(PPh₃)₄] (M = Pt, Pd) and [IrCl(CO)(PMePh₂)₂] to give the adducts [(C₇F₈)M(PPh₃)₂] and [(C₇F₈)IrCl(CO)(PMePh₂)₂] in which one of the double bonds is coordinated to the metal atom. The platinum complex reacts further with [Pt(PPh₃)₄] to give [(C₇F₈){Pt(PPh₃)₂}₂] having both double bonds coordinated to a Pt atom. The carbonylmetal anions [M^?] react to form the mono-substitution products [(C₇F₇)M] (M = Mn(CO)₅, Re(CO)₅, Ir(CO)₂(PPh₃)₂, Rh(CO)₂(PPh₃)₂), but the use of an excess of [Fe(CO)₂(η-C₅H₆)]^? leads to substitution of one fluorine atom on each of the double bonds. The complex having M = Mn(CO)₅ reacts with [Pt(PPh₃)₄] to afford the derivative [(C₇F₇){Mn(CO)₄(PPh₃)}{Pt(PPh₃)₂}], and the compound where M = Ir(CO)₂(PPh₃)₂ undergoes an oxidative addition reaction with acetyl chloride. Oxidative coupling products have been isolated on UV irradiation of a mixture of perfluoronorbornadiene and [Fe(η⁴-CH₂CRCHCH₂)(CO)₃] (R = H, Me), and under similar conditions the reaction with Fe(CO)₅ affords [(C₇F₈)Fe(CO)₄] in very low yield.     

The Synthesis by Decarboxylation Reactions and Crystal Structures of 1, n–Bis(diphenylphosphino)alkane(pentafluorophenyl)‐platinum(II) Complexes

Decarboxylation reactions between the complexes cis–[PtCl₂L] (L = 1, n–bis(diphenylphosphino)–ethane (n = 2, dppe), –propane (n = 3, dppp) or –butane (n = 4, dppb)) and thallium(I) pentafluorobenzoate in pyridine give cis–[PtCl(C₆F₅)L] and cis–[Pt(C₆F₅)₂L] complexes in high yields with short reaction times. X–ray crystal structures of cis–[PtCl(C₆F₅)(dppe)] · 0.5 C₅H₅N, cis–[PtCl(C₆F₅)(dppp)], cis–[PtCl(C₆F₅)(dppb)] · C₃H₆O, cis–[Pt(C₆F₅)₂L] (L = dppe, dppp and dppb) and the reactants cis–[PtCl₂(dppp)] (as a CH₂Cl₂ solvate) and cis–[PtCl₂(dppb)] show monomeric structures with chelating diphosphine ligands in all cases rather than dimers with bridging diphosphines. ³¹P NMR data are consistent with these structures in solution.