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.     

Reaktionen von Gemischtligand-Komplexen des Nickel(0) mit Kohlenstoffdichalcogeniden

Reactions of Mixed Ligand Complexes of Nickel(0) with Carbon Dichalcogenides Decisive for the occurrence of a reaction between mixed ligand complexes of nickel(0) and carbon dichalcogenides is the HOMO-energy of the complex and the LUMO-energy of the reagent, which are reflected in the corresponding polarographic half-wave potentials. Therefore, (dipy)-Ni(COD) is substituted by SeCS, CS₂ and SCO, whereas (PPh₃)₂Ni(C₂H₄) only reacts with CS₂, but not with SCO. Substitution by CO₂ needs substrates like Ni(PCy₃)₃ or Ni(PEt₃)₄ which have the lowest anodic waves. (PCy₃)₂Ni(C₂H₄) and (dipy)Ni(PPh₃)₂ effect C?S-bond breaking in SCO, and mixed carbonyls, such as (PCy₃)₂Ni(CO)₂ or (PPh₃)₂Ni(CO)₂, are formed. Futher products are dithiocarbonates or oligonuclear nickel sulfides which are stabilized by a phosphine. Another oligonuclear complex, (PPh₃)₂Ni₃(CS₂)₂, is formed by the reaction of CS₂ with surplus (PPh₃)₂Ni(C₂H₄). The function of CS₂ is that of a bridging ligand. The carbon dichalcogenides are side-on (η²) coordinated in compounds like (dipy)Ni(CS₂), (PPh₃)Ni(CS₂) and (dipy)Ni(SCO). It is always the highest electronegative heteroatom of the non symmetric ligands SeCS and SCO which does not interact with the central atom.     

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.     

Oxidative addition and insertion reactions of cyclic alkyne-platinum(0) complexes

The reactions of various alkyne-platinum(0) complexes with methyl iodide and with iodine have been studied. The 3-hexyne complex Pt(C₂H₅C₂C₂H₅)(PPh₃)₂ gives alkyne-free oxidative addition products PtI(CH₃) (PPh₃)₂ and PtI₂ (PPh₃)₂ exclusively. In contrast, the strained cyclic alkyne complexes Pt(C₆H₈)(PPh₃)₂, Pt(C₇H₁₀)(PPh₃)₂, Pt(C₆H₈) (dppe) and Pt(C₇H₁₀) (dppe)¹ react with methyl iodide to give mainly 2-methylcycloalkenyiplatinum(II) complexes, e.g. PtI(C₆H₈CH₃) (PPh₃)₂, formed by electrophilic attack on the metal-alkyne bond. Iodine reacts similarly with Pt(C₆H₈) (PPh₃)₂ and Pt(C₇H₁₀) (PPh₃)₂ to give 2-iodocycloalkenylplatinum(II) complexes but, in the case of the corresponding dppe complexes, PtI₂(dppe) is the main product. The insertion reaction of methyl iodide with Pt(C₆H₈)(PPh₃)₂ proceeds via an oxidative addition intermediate PtI(CH₃) (C₆H₈) (PPh₃)₂ which can be isolated. Trifluoromethyl iodide reacts with Pt(C₆H₈)(PPh₃)₂ to give a 2-iodocyclohexenyl complex Pt(CF₃) (C₆H₈I) (PPh₃)₂ and with Pt(C₇H₁₀) (PPh₃)₂ to give PtI(CF₃) (PPh₃)₂. ³¹P NMR data are given and discussed.     

Coordination chemistry of sulfines : I. Synthesis and characterization of the complexes Pt(PPh3)2(XYCSO) (X,Y = aryl,S-aryl,S-alkyl,Cl). Coordination via the CS-π-bond

Reactions of Pt(PPh₃)₄ with the sulfines, XYCSO, (X, Y = aryl, S-aryl, S-alkyl, Cl) yield coordination compounds of the type Pt(PPh₃)₂(XYCSO). Infrared, ³¹P and ¹H NMR spectra reveal that in all cases the sulfine ligand is coordinated side-on via the CS π-bond (Pt—η²-CS). Reactions of Pt(PPh₃)₄ with either the E- or Z-isomer of (p-CH₃C₆H₄)(CH₃S)CSO yields the corresponding E- or Z-coordination compound, Pt(PPh₃)₂[E-(p-CH₃C₆H₄)(CH₃S)CSO] or Pt(PPh₃)₂[Z-(p-CH₃C₆H₄)(CH₃S)CSO], indicating that the configuration of the sulfine ligand is retained upon coordination to the Pt(PPh₃)₂ unit. The compounds Pt(PPh₃)₂(XYCSO), containing reactive CX and/or CY bonds (X, Y = S-aryl, S-alkyl, Cl), undergo a rearrangement in solution to give complexes of the type PtX(PPh₃)₂(YCSO).     

Structural and Photophysical Study on Heterobimetallic Complexes with d8–d10 Interactions Supported by Carborane Ligands: Theoretical Analysis of the Emissive Behaviour

Heterobimetallic complexes of formula [M{(PPh₂)₂C₂B₉H₁₀}(S₂C₂B₁₀H₁₀)M′(PPh₃)] (M=Pd, Pt; M′=Au, Ag, Cu) and [Ni{(PPh₂)₂C₂B₉H₁₀}(S₂C₂B₁₀H₁₀)Au(PPh₃)] were obtained from the reaction of [M{(PPh₂)₂C₂B₁₀H₁₀}(S₂C₂B₁₀H₁₀)] (M=Pd, Pt) with [M′(PPh₃)]⁺ (M′=Au, Ag, Cu) or by one‐pot synthesis from [(SH)₂C₂B₁₀H₁₀], (PPh₂)₂C₂B₁₀H₁₀, NiCl₂ ? 6 H₂O, and [Au(PPh₃)]⁺. They display d⁸–d¹⁰ intermetallic interactions and emit red light in the solid state at 77 K. Theoretical studies on [M{(PPh₂)₂C₂B₉H₁₀}(S₂C₂B₁₀H₁₀)Au(PPh₃)] (M=Pd, Pt, Ni) attribute the luminescence to ligand (thiolate, L)‐to‐“P₂‐M‐S₂” (ML′) charge‐transfer (LML′CT) transitions for M=Pt and to metal (M)‐to‐“P₂‐M‐S₂” (ML′) charge‐transfer (MML′CT) transitions for M=Ni, Pd.     

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)°.     

Platinum-mercury compounds as intermediates to mono- and di-arylplatinum(II) complexes

The reaction of HgR₂ (R = 2,5-C₆H₃Cl₂; 2,3,4- and 2,4,6-C₆H₂Cl₃; 2,3,4,5-,2,3,4,6- and 2,3,5,6-C₆HCl₄ and C₆Cl₅) with Pt(PPh₃)₃ gives the new stable compounds [(PPh₃)₂RPt(HgR)] containing PtHg bonds. When R contains an ortho chlorine atom (R = 2,5-C₆H₃Cl₂; 2,3,4-C₆H₂Cl₃ and 2,3,4,5-C₆HCl₄) refluxing xylene solutions of these compounds gives the complexes [PtR₂-(PPh₃)₂], with simultaneous precipitation of mercury. In the other cases the initial compounds are recovered unaltered. All the compounds containing the PtHg bond react readily with CF₃COOH to give a new series of compounds of formula [Pt(O₂CCF₃)R(PPh₃)₂].     

DECARBONYLATION OF ACYLCHLOROBIS-(TRIPHENYLPHOSPHINE) PLATINUM(II) COMPLEXES PROMOTED BY TIN(II) CHLORIDE

Abstract

While it might be expected that the availability of vacant coordination sites in the four coordinate acyl complexes trans[Pt(PPh₃)₂ (RCO)Cl] provides low energy pathways for alkyl and aryl migration and subsequent decarbonylation, the decarbonylation has been previously achieved only at elevated temperatures. The addition of SnCl₂ greatly facilitates decarbonylation of [Pt(PPh₃)₂ (RCO)Cl] where R is CH₃, C₂ H₅, Y[sbnd]C₆ H₄. Compounds of the type [Pt(PPh₃)₂ (RCO)SnCl₃] and [Pt(PPh₃)₂ R(SnCl₃)] have been isolated. The removal of SnCl₂ from these compounds has been achieved with ethanol. A kinetic study of the decarbonylation of [Pt(PPh₃)₂ (RCO)SnCl₃] (where R is CH₃, C₂ H₅, Y[sbnd]C₆ H₄ for Y=H, CH₃, CH₃ O, NO₂, Cl) is reported. The role of 3 and 5 coordinate intermediates in alkyl-aryl migrations in Pt(II) systems is discussed.     

New cationic aryldiazo,aryldiimine and arylhydrazine complexes of platinum

The preparation of some new cationic aryldiazo complexes of platinum of formula trans-[Pt(N₂Ar)(PEt₃)₂L]⁺, where N₂Ar = N₂C₆H₄F-m or -p and L = NH₃, Py, Et₃P or EtNC, is described. Protonation of these complexes gives the corresponding aryldiimide complexes trans-[Pt(NHNAr)(PEt₃)₂L]⁺, and reduction of the protonated complexes with molecular hydrogen in the presence of a catalyst gives the arylhydrazine complexes trans-[Pt(NH₂NHAr)(PEt₃)₂L]⁺. Some of the spectroscopic properties of these new complexes are reported and discussed.     

Pseudohalogenometallverbindungen: LVIII. Reaktionen von diphenylphosphorylazid und perfluor-n-hexylsulfonylazid mit triphenylphosphan-komplexen von platin(0), rhodium(I), iridium(I), ruthenium(0), kobalt(II) und kupfer(I)

Diphenylphosphorylazide N₃P(O)(OPh)₂ reacts with Pt(PPh₃)₃, Pt(PPh₃)₂(C₂H₄), trans-RhCl(CO)(PPh₃)₂, Ru(CO)₃(PPh₃)₂, CoCl₂(PPh₃)₂ and CuCl(PPh₃)₂ to give the azido complexes Pt(PPh₃)₂(N₃)R, Pt(PPh₃)₂(N₃)₂R₂, the urylene complex RhCl(PPh₃)₂(RNCONR) and the phosphine imine complexes Ru(CO)₃(RPPh₃)₂, CoCl₂(RNPPh₃)₂, CuCl(RNPPh₃)₂, respectively, (RP(O)(OPh)₂). The oxidative addition of n-C₆F₁₃SO₂N₃ to Pt(PPh₃)₄ and Pt(PPh₃)₂(C₂H₄) affords the complexes Pt(PPh₃)₂(N₃)R and Pt(PPh₃)₂(N₃)₂R₂, respectively, (RSO₂C₆F₁₃. The compounds are characterized by elemental analysis and by their IR spectra.     

Untersuchungen zur Koordinationsfähigkeit potentiell dreizähliger N-substituierter Salicylaldimine gegenüber 3d-Elementen. II. Liganden mit Organophosphan- und Organoarsan-Gruppierungen in der Seitenkette

Studies of Tridentate Coordination Ability of N-subsituted Salicylaldimines with 3d Elements. II. Ligands with Organophosphin and Organoarsin Groups in the side Chain N-substituted salicylaldiminates with tertiary phosphine or arsine groups in the side chain form 1,2-complexes with cations of the 3d elements. In the chelates Cu(ON2PPh₂)₂, Cu(ON2AsPh₂)₂, Cu(ON3AsPh₂)₂, Ni(ON2PPh₂)₂, Ni(ONSAsPh₂)₂, and Ni(ON3AsPh₂)₂ (about abbreviations see text) the central atoms have the coordination number 4, no coordination of the phosphine and arsine groups is observed. On the other hand the N-substituted salicylaldiminates are tridentate in the octahedral complexes Ni(ON2PEt₂)₂, Co(ON2PEt₂)₂, and Co(ON3AsPh₂)₂. The dissolution of the new chelates in pyridine is always connected with a structural change, the dissolution in benzene only in some cases. With nickel(II) a binuclear compound [Ni(ON2PPh)]₂ C₄H₉OH containing the anion of the SCHIFF base between salicylaldehyde and β-aminoethyl phcnylphosphine, which is unstable in the free state, has been obtained.     

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.     

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.     

Insertion of the Pt(PPh3)2 unit into inorganic triatomic rings coordinated to metal—ligand moieties

Reaction of the [(triphos)Co(E₂S)]BF₄ complexes (triphos = 1,1,1-tris(di-phenylphosphinomethyl)ethane, E = P or As) containing the P₂S or As₂S cyclic units trihapto(η³-bonded to the metal, with (C₂H₄)Pt(PPh₃)₂ involves insertion of the Pt(PPh₃)₂ moiety into a bond of the inorganic ring, yielding the compounds [(triphos)Co(E₂S)Pt(PPh₃)₂]BPh₄ (E = P or As), whose structures have been determined by X-ray diffraction studies.     

Reactions of zero-valent platinum complexes with some diacetylenes

The complexes[Pt(C₂H₄)L₂] (L = PPh₃ or PMePh₂) react with 1,4-diphenyl-buta-1,3-diyne to give, successively, mono- and di-platinum compounds [Pt-(PhC₄Ph)L₂] and [Pt₂(PhC₄Ph)L₄]. Hexa-2,4-diyne and [Pt(C₂H₄)(PPh₃)₂] react similarly. In the di-platinum compounds both acetylenic linkages are η²-bonded to platinum atoms, as also occurs in the complex [Pt₂{HC₂(CH₂)₂C₂H}(PPh₃)₄] obtained from hexa-1,5-diyne. Reaction of [Pt₃(CN-t-Bu)₆ with 1,4-diphenylbuta-1,3-diyne and hexa-2,4-diyne affords di-platinum complexes, shown by spectroscopic studies to have structures containing diplatinacyclobutene rings.     

Komplexchemie perhalogenierter Cyclopentadiene und Alkine: III. Reaktion von Pt(PPh3)2(C2H4) mit Monofluoracetylen und Dichloracetylen. Kristallstruktur von Pt(PPh3)2(Cl)(CCCl)

Pt(PPh₃)₂(C₂H₄) reacts with monofluoroacetylene to give the π-complex Pt(PPh₃)₂(FCCH), and with dichloroacetylene under oxidative addition to yield Pt(PPh₃)₂(Cl)(ClCCl), the structure of which was determined by X-ray crystallography.     

Oxidative addition of boron–boron, boron–chlorine and boron–bromine bonds to platinum(0)

The synthesis and spectroscopic characterisation of the new diborane(4) compounds B₂(1,2-O₂C₆Cl₄)₂ and B₂(1,2-O₂C₆Br₄)₂ are reported together with the diborane(4) bis-amine adduct [B₂(calix)(NHMe₂)₂] (calix=Bu^tcalix[4]arene). B–B bond oxidative addition reactions between the platinum(0) compound [Pt(PPh₃)₂(η-C₂H₄)] and the diborane(4) compounds B₂(1,2-S₂C₆H₄)₂, B₂(1,2-O₂C₆Cl₄)₂ and B₂(1,2-O₂C₆Br₄)₂ are also described which result in the platinum(II) bis-boryl complexes cis-[Pt(PPh₃)₂{B(1,2-S₂C₆H₄)}₂], cis-[Pt(PPh₃)₂{B(1,2-O₂C₆Cl₄)}₂] and cis-[Pt(PPh₃)₂{B(1,2-O₂C₆Br₄)}₂] respectively, the former two having been characterised by X-ray crystallography. In addition, the platinum complex [Pt(PPh₃)₂(η-C₂H₄)] reacts with XB(1,2-O₂C₆H₄) (X=Cl, Br) affording the mono-boryl complexes trans-[PtX(PPh₃)₂{B(1,2-O₂C₆H₄)}] as a result of oxidative addition of the B–X bonds to the Pt(0) centre; the chloro derivative has been characterised by X-ray crystallography.     

Clathrate compounds of tetracyano complexes of nickel and platinum with phenol

The double cyanides of nickel and platinum form structures capable of enclosing also phenol, for example, as guest molecule. Such clathrates are Ni(NH₃)₂Pt(CN)₄ 2 C₆H₅OH and Ni(en)₂Pt(CN)₄ · 0.14 C₆H₅OH. In the case of the tetracyano complexes, different thermal stabilities of their clathrate compounds could be achieved by alteration of the constituents of the cage structure and also of the guest molecules. According to the thermal behaviour, the clathrates may be divided into two groups: those which release the guest molecules in the first step of thermal decomposition (Ni(NH₃)₂Pt(CN)₄· 2 C₆H₅OH), and those which lose the guest component only after partial destruction of the host cage (Ni(en)₂Pt(CN)₄ · 0.14 C₆H₅OH). The temperature ranges of loss of the guest component may determine the interval for their use in sorptive experiments. The temperature range for release of phenol from Ni(NH₃)₂Pt(CN)₄ · · 2 C₆H₅OH is 55–244°, and from Ni(en)₂Pt(CN)₄ · 0.14 C₆H₅OH is 139–284°. The model host molecules NiPt(CN)₄ · 6 H₂O and Ni(en)₃Pt(CN)₄ · 3 H₂O were also studied by thermal analysis.     

[Bis(2‐diphenylphosphinoethyl) sulfide‐κ3P,S,P′](triphenylphosphine‐κP)platinum(II) diperchlorate acetone solvate

In the title compound, [Pt(C₁₈H₁₅P)(C₂₈H₂₈P₂S)]­(ClO₄)₂·­C₃H₆O or [Pt(PPh₃)(PSP)](ClO₄)₂·CH₃COCH₃, where PSP is the potentially tridentate chelate ligand bis(2‐di­phenyl­phosphinoethyl) sulfide, all three donor groups of the PSP ligand are coordinated to the central Pt atom, with Pt—P = 2.310 (1) Å and Pt—S = 2.343 (1) Å. The fourth coordination site is occupied by the P donor of the tri­phenyl­phosphine ligand [Pt—P = 2.289 (1) Å]. The complex cation has exact mirror symmetry, with the S atom, the Pt atom and the P atom of the PPh₃ ligand in the mirror plane. The Pt atom has a distorted square‐planar coordination geometry. A π–π interaction is present between the phenyl rings of the PPh₃ ligand and the terminal –PPh₂ group of the PSP chelate.