Metallkomplexe mit biologisch wichtigen Liganden. LXXXII. Triphenylphosphan-Molybdän-, Wolfram-, Ruthenium- und Iridium-Komplexe mit N-acylierten α-Aminocarboxylaten

Metal Complexes of Biological Important Ligands. LXXXII. Triphenylphosphine Molybdenum, Tungsten, Ruthenium, and Iridium Complexes of N-Acyl-α-Aminocarboxylates The reactions of the hydrido complexes RuHCl(CO) · (PPh₃)₃, RuH₂(PPh₃)₄ and IrH₃(PPh₃)₃ with N-acyl-α-aminocarboxylates give the carboxylate complexes RuCl(O₂CCHRNHCOR′)(CO)(PPh₃)₂ ( 1–3 ), RuH(O₂CCHRNHCOR′)(PPh₃)₃ ( 4–6 ) and IrH₂(O₂CCH₂NHCOPh)(PPh₃)₃ ( 7 ). The structure of RuCl · (O₂CCHNHCOPh)(CO)(PPh₃)₂ ( 1 ) has been determined by x-ray diffraction. The triphenylphosphine complexes MBr · (O₂CCH₂NHCOR)(CO)₂(PPh₃)₂ (M = Mo, W) ( 8–12 ) and Mo(O₂CCHRNHCOR′)₂(CO)₂(PPh₃)₂ ( 13–17 ) are formed from MBr₂(CO)₂(PPh₃)₂ (M = Mo, W) with one or two equivalents of N-acyl-a-aminoacidates, respectively.     

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.     

The Staudinger reaction of platinum(II)- and palladium(II)-coordinated 2-(azidomethyl)phenyl isocyanide. X-ray structure of trans-[PtCl{(H)}(PPh3)2][BF4] · CDCl3 · H2O

2-(Azidomethyl)phenyl isocyanide, 2-(CH₂N₃)C₆H₄NC (AziNC), coordinates to some cationic Pt(II) and Pd(II) species to afford isocyanide complexes of the type trans-[MCl(AziNC)(PPh₃)₂][BF₄] (M=Pt, l; Pd, 2). AziNC is coordinated also in some neutral Pt(II) and Pd(II) species such as [MCl₂(AziNC)₂] (M=Pt, 3; Pd, 4) derived from the reactions of 2 equiv. of AziNC with [PtCl₂(COD)] and [PdCl₂(MeCN)₂], respectively. Complexes 1 and 2 react with 1 equiv. of PPh₃ affording the heterocyclic carbene complexes trans-[MCl{(H)}(PPh₃)₂][BF₄] (M=Pt, 5; Pd, 6). Complexes 3 and 4 react with 1 equiv. of PPh₃ displacing the isocyanide with the formation of the complexes cis-[MCl₂(AziNC)(PPh₃)] (M=Pt, 7; Pd, 8). These latter ones react with 2 equiv. of PPh₃ affording as the final products the cationic carbene species trans-[MCl{(H)}(PPh₃)₂][Cl] (M=Pt, 9; Pd, 10). Complex 5 was also characterized by single crystal X-ray diffraction. The carbene complex is square-planar and the angle formed between the platinum square plane and the heterocyclic carbene ligand is 87.9(2)°. The C(1)-N(1) and C(1)-N(2) bond distances in the latter of 1.32(2) and 1.30(2) Å, respectively, are short for a single bond and indicate extensive π-bonding between the nitrogen atoms and the carbene carbon.     

Synthesis and characterization of cyclometallated palladium(II) and platinum(II) complexes with amide-thiolate ligands

The redox reaction of bis(2-benzamidophenyl) disulfide (H₂L-LH₂) with [Pd(PPh₃)₄] in a 1:1 ratio gave mononuclear and dinuclear palladium(II) complexes with 2-benzamidobenzenethiolate (H₂L⁻), [Pd(H₂L-S)₂(PPh₃)₂] (1) and [Pd₂(H₂L-S)₂ (μ-H₂L-S)₂(PPh₃)₂] (2). A similar reaction with [Pt(PPh₃)₄] produced only the corresponding mononuclear platinum(II) complex, [Pt(H₂L-S)₂(PPh₃)₂] (3). Treatment of these complexes with KOH led to the formation of cyclometallated palladium(II) and platinum(II) complexes, [Pd(L-C,N,S)(PPh₃)]⁻ ([4]⁻) and [Pt(L-C,N,S) (PPh₃)]⁻ ([5]⁻). The molecular structures of 2, 3 and [4]⁻ were determined by X-ray crystallography.     

Platinum(II), palladium(II), nickel(II), and gold(I) complexes of the “electrospray-friendly” thiolate ligands 4-SC5H4N− and 4-SC6H4OMe−

The series of platinum(II), palladium(II), and nickel(II) complexes [ML₂(dppe)] [M = Ni, Pd, Pt; L = 4–SC₅H₄N or 4–SC₆H₄OMe; dppe = Ph₂PCH₂CH₂PPh₂] containing pyridine-4-thiolate or 4-methoxybenzenethiolate ligands, together with the corresponding gold(I) complexes [AuL(PPh₃)], were prepared and their electrospray ionization mass spectrometric behavior compared with that of the thiophenolate complexes [M(SPh)₂(dppe)] (M = Ni, Pd, Pt) and [Au(SPh)(PPh₃)]. While the pyridine-4-thiolate complexes yielded protonated ions of the type [M + H]⁺ and [M + 2H]²⁺ ions in the Ni, Pd, and Pt complexes, an [M + H]⁺ ion was only observed for the platinum derivative of 4-methoxybenzenethiolate. Other ions, which dominated the spectra of the thiophenolate complexes, were formed by thiolate loss and aggregate formation. The X-ray crystal structure of [Pt(SC₆H₄OMe–4)₂(dppe)] is also reported.     

Palladium complexes of a chiral P,C-chelating phosphino-(sulfinylmethyl)phosphonium ylide ligand

A new type of phosphino-phosphonium ylide ligand bearing a chiral sulfinyl center affords a P,C-chelated palladium(II) complex with a resolved asymmetric ylidic carbon atom. According to ³¹P NMR analysis of the crude material, the diastereoselectivity of the complexation at room temperature is ca. 7:1. In the crystal state, an X-ray diffraction analysis of one epimer reveals a quasi C₂-symmetric chloro-bridged dinuclear structure, where the (S) configuration of the sulfur atom induces a (S) configuration of the ylidic carbon atom. A in situ Pd(0) catalyst generated from the phosphino-ylide and Pd(PPh₃)₄ promotes allylic substitution of 3-acetoxy-1,3-diphenylpropene by sodium malonate in 70% yield and 5% e.e.     

Anion effect on the coordination behavior of N,O-hybrid pyrazole ligand towards Pd(II): synthesis,characterization, and supramolecular properties

Four new Pd(II) coordination complexes using 2-(3-methyl-5-phenyl-1H-pyrazol-1-yl)ethanol (L) with different counter-anions have been prepared to examine their effect on the coordination mode of the ligand as well as on the self-assembly of the supramolecular structure. Reaction of trans-[PdCl₂(L)₂] (R) with AgCF₃SO₃ gives the ionic complex [Pd(L)₂](CF₃SO₃)₂ (1). When AgNO₃ is used, [Pd(NO₃)(L)₂](NO₃) (2) and [Pd(L)₂](NO₃)₂ (3) are obtained in the ratio 70?:?30, respectively, where the nitrate ion is present in- and/or outside the coordination sphere. Reaction of R with Ag₂SO₄ in the presence of (NH₄)₂C₂O₄ yields [Pd(C₂O₄)(L)₂] (4). These new complexes have been characterized by elemental analyzes, conductivity measurements, mass spectrometry, IR, ¹H and ¹³C{¹H} NMR spectroscopies, and X-ray diffraction, whenever possible. The denticity varies from N-monodentate to NO-bidentate, depending on the conditions, showing the versatility of L. Finally, the results of X-ray diffraction analyzes of 1 reveal that CF₃SO₃^? plays a fundamental role in self-assembly, generating a 2-D supramolecular layer with different inter- and intra-molecular interactions. The easy preparation and the high efficiency of this ligand make it a promising alternative to improve established systems.     

Kinetics and mechanism of the reactions of hexaaqua rhodium (III) with sulphur (IV) in aqueous medium

An O-bonded sulphito complex, Rh(OH₂)₅(OSO₂H)²⁺, is reversibly formed in the stoppedflow time scale when Rh(OH₂) ₆ ³⁺ and SO₂/HSO ₃ ⁻ buffer (1 <pH< 3) are allowed to react. For Rh(OH₂)₅OH₂₊+ SO₂ □ Rh(OH₂)₅(OSO₂H)²⁺ (k₁/k_-1), k₁ = (2.2 ±0.2) × 10³ dm³ mol⁻¹ s⁻¹, k₋1 = 0.58 ±0.16 s⁻¹ (25°C,I = 0.5 mol dm⁻³). The protonated O-sulphito complex is a moderate acid (K _d = 3 × 10⁻⁴ mol dm⁻³, 25°C, I= 0.5 mol dm⁻³). This complex undergoes (O, O) chelation by the bound bisulphite withk= 1.4 × 10⁻³ s⁻¹ (31°C) to Rh(OH₂)₄(O₂SO)⁺ and the chelated sulphito complex takes up another HSO ₃ ⁻ in a fast equilibrium step to yield Rh(OH₂)₃(O₂SO)(OSO₂H) which further undergoes intramolecular ligand isomerisation to the S-bonded sulphito complex: Rh(OH₂)₃(O₂SO)(OSO₂)^- → Rh(OH₂)₃(O₂SO)(SO₃)⁻ (k _iso = 3 × 10⁻⁴ s⁻¹, 31°C). A dinuclear (μ-O, O) sulphite-bridged complex, Na₄[Rh₂(μ-OH)₂(OH)₂(μ-OS(O)O)(O₂SO)(SO₃) (OH₂)]5H₂O with (O, O) chelated and S-bonded sulphites has been isolated and characterized. This complex is sparingly soluble in water and most organic solvents and very stable to acid-catalysed decomposition     

Synthesis and crystal structures of new palladium catalysts for the hydromethoxycarbonylation of alkenes

The preparation and structural characterization of dimeric Pd(I)-Pd(I) complex [Pd₂{(PPh₃)(OSO₂CF₃)}₂].CH₂Cl₂ (1) and three palladium center [Pd₃{(PPh₃)(OSO₂CF₃)}₂] (2) and [Pd₃(PPh₃)₄](SO3CF₃)₂ (3) complexes are reported. The complexes exhibit coordination in which the phosphine phenyl ring is used to stabilize Pd(I) centers in (1) and, Pd(I) and Pd(0) centers in (2) and (3) by acting as π electron donors. The complexes were characterized by single crystal X-ray crystallography.     

Synthesis and reactions of some sulfur ylide complexes of palladium

The iodo-bridged sulfur ylide complex [Pd(μ-I)((CH₂)₂(SO)(CH₃))]₂ (1) when treated with dithiolates, acetylacetone and various Lewis bases gave [Pd((CH₂)₂(SO)(CH₃))(S ∼ S)] (S ∼ S = S₂CN(C₂H₅)₂, S₂COC₂H₅ and S₂P(OC₂H₅)₂), [Pd((CH₂)₂(SO)(CH₃))(acac)] (acac = acetylacetonate) and [PdI((CH₂)₂(SO)(CH₃))(base)]a (base = PPh₃, (P(OMe)₃, P(OPh)₃ and C₅H₅N). In the presence of a phase transfer catalyst (PTC). The reactions rates and yields were greatly increased. Reaction of several related sulfur ylide complexes with I₂, HI or aqueous NaOH gave 1. The single crystal structure of [Pd((CH₂)₂(SO)(CH₃))₂] was determined (orthorhombic, Pbcn, a 13.379(2), b 8.081(1), c 9.048(2) Å, V 978.2 ų, Z = 4). The compound has a rather long PdCH₂ bond (2.096(1) Å, mean).     

Synthese und Struktur der Nitrido‐Komplexe (PPh4)2[(O3Os≡N)2MCl2](M = Pd und Pt) und [{(Me2PhP)3Cl2Re≡N}2PdCl2]

Synthesis and Structure of the Nitrido Complexes (PPh₄)₂[(O₃Os≡N)₂ MCl₂] (M = Pd und Pt) and [{(Me₂PhP)₃Cl₂Re≡N}₂PdCl₂] The threenuclear complexes (PPh₄)₂[(O₃Os≡N)₂MCl₂] (M = Pd ( 1a ) and Pt ( 1b )) are obtained by the reaction of (PPh₄) [OsO₃N] with [MCl₂(NCC₆H₅)₂] (M = Pd and Pt) in form of orange red ( 1a ) or red brown ( 1b ) crystals. The compounds crystallize isotypically in the monoclinic space group P2₁/n with a = 1052.35(6), b = 1376.70(6), c = 1607.3(1) pm, β = 94.669(7)°, and Z = 2 for 1a and a = 1053.27(7), b = 1371.6(1), c = 1615.9(1) pm, β = 94.557(7)°, and Z = 2 for 1b . In the centrosymmetric complex anions [(O₃O≡N)₂MCl₂]^2— a linear MCl₂ moiety is connected in trans arrangement with two complexes [O₃Os≡N]^— via asymmetric nitrido bridges Os≡N‐M. For the M²⁺ cations such results a square‐planar coordination MCl₂N₂. The virtually linear nitrido bridges are characterized by distances Os‐N = 167.5 pm ( 1a ) and 164.2 pm ( 1b ) as well as Pd‐N = 196.2 pm and Pt‐N = 197.8 pm. The reaction of ReNCl₂(PMe₂Ph)₃ with PdCl₂(NCC₆H₅)₂ in CH₂Cl₂ yields red crystals of the heterometallic complex [{(Me₂PhP)₃Cl₂Re≡N}₂PdCl₂] ( 2 ). It crystallizes as 2 · 2 CH₂Cl₂ in the monoclinic space group C2/c with a = 2138.3(5); b = 1260.9(3); c = 2375.6(2) pm; β = 96.09(1)° and Z = 4. In the threenuclear complex [{(Me₂PhP)₃Cl₂Re≡N}₂PdCl₂] with the symmetry C_i the coordination of the Pd²⁺ cation of the central PdCl₂ unit is completed by two nitrido bridges Re≡N‐Pd to complexes (Me₂PhP)₃Cl₂Re≡N forming a square‐planar arrangement. The distances in the linear nitrido bridges are Re‐N = 170.2 pm and Pd‐N = 197.1 pm.     

Reduction of nitrobenzene in the liquid phase by carbon monoxide (II) in the presence of palladium complexes

Conclusions We investigated the transformations of catalysts based on palladium complexes under the conditions of the catalytic reduction of nitrobenzene by carbon monoxide (II). We established that the reduced forms of the catalyst are Pd₂(PPh₃),₄(CO)·H₂SO₄ and Pd₂PPh₃)₄CO)· HClO₄, while the reduced forms are Pd(PPh₃)₂SO₄ and Pd(PPh₃)₃(H₂O)(ClO₄)₂ in the sulfate and the perchlorate media, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 998–1002, May, 1989.     

Transition metal chemistry of phosphorus based ligands. Ruthenium(II) chemistry of bis(phosphino)amines, X2PN(R)PX2 (R=H or Ph, X=Ph; R=Ph, X2=O2C6H4)

Reactions of CpRuCl(PPh₃)₂ with bis(phosphino)amines, X₂PN(R)PX₂ (1 R=H, X=Ph; 2 R=X=Ph; 3 R=Ph, X₂=O₂C₆H₄) give neutral or cationic mononuclear complexes depending on the reaction conditions. Reaction of 1 with CpRuCl(PPh₃)₂ gives one neutral complex, [CpRu(Cl)(η²-Ph₂PN(H)PPh₂)] (4) and two cationic complexes, [CpRu(η²-Ph₂PN(H)PPh₂)(η¹-Ph₂PN(H)PPh₂)]Cl (5) and [CpRu(PPh₃)(η²-Ph₂PN(H)PPh₂)]Cl (6), whereas the reaction of 2 with CpRuCl(PPh₃)₂ leads only to the isolation of cationic complex, [CpRu(PPh₃)(η²-Ph₂PN(Ph)PPh₂)]Cl (7). The catechol derivative 3, in a similar reaction, affords an interesting mononuclear complex [CpRu(PPh₃){η¹-(C₆H₄O₂)PN(Ph)P(O₂H₄C₆)}₂]Cl (8) containing two monodentate bis(phosphino)amine ligands. The structural elucidation of the complexes was carried out by elemental analyses, IR and NMR spectroscopic data.     

Conversion of iminoacyl quinolinylpalladium (II) complexes into novel oxo‐pyrrolo[3,4‐b] quinolines via depalladation reactions

Oxidative addition reactions of quinolines 1a , b with Pd(dba)₂ in the presence of PPh₃ (1:2) in acetone gave dinuclear palladium complexes [Pd(C,N‐2‐C₉ H₄N‐CHO‐3‐R‐6)Cl(PPh₃)]₂ [(R = H ( 2a ), R = OMe ( 2b ), which were reacted with isocyanide XyNC (Xy = 2,6‐Me₂C₆H₃) to give novel iminoacyl quinolinylpalladium complexes 3a , b in good yields (81 and 77%). Cyclopalladated complexes 3a , b were also obtained in low yields (39 and 33.5%) via one‐pot reaction of 1a , b with isonitrile XyNC:Pd(dba)₂ (4:1). The reaction of 3a , b with Tl(TfO) (TfO = triflate, CF₃SO₃) in the presence of H₂O or EtOH causes depalladation reactions of complexes to provide the corresponding organic compounds 4a , b , 5a , b and 6a , b in yields of 41, 27 and 18 ? 19%, respectively. The products were characterized by satisfactory elemental analyses and spectral studies (IR, ¹H, ¹³C and ³¹P NMR). The crystal structures 2a , 3a and 3b were determined by X‐ray diffraction studies. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthese und Kristallstrukturen von (PPh4)2[In(S4)(S6)Cl] und (PPh4)2[In(S4)Cl3]

Synthesis and Crystal Structures of (PPh₄)₂[In(S₄)(S₆)Cl] and (PPh₄)₂[In(S₄)Cl₃] InCl and PPh₄Cl yield (PPh₄)₂[In₂Cl₆] in acetonitrile. This reacts with Na₂S₄ in presence of PPh₄Cl, forming (PPh₄)₂[In(S₄)(S₆)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh₄)₂[In(S₄)(S₆)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S₄ and S₆ groups being bonded in a chelate manner. The reaction of (PPh₄)₂[In₂Cl₆] and sulfur in acetonitrile yielded (PPh₄)₂[InCl₅] and (PPh₄)₂[In(S₄)Cl₃]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S₄ group occupying one axial and one equatorial position; the S₄ group shows positional disorder.     

1‐Azaallyl Complexes of NiII,PdII, and TiIII

The metal complexes [Ni{N(Ar)C(R)C(H)Ph}₂) ( 2 ) (Ar = 2,6‐Me₂C₆H₃, R = SiMe₃), [Ti(Cp₂){N(R)C(Bu^t)C(H)R}] ( 3 ), M{N(R)C(Bu^t)C(H)R}I [M = Ni ( 4 a ) or Pd ( 4 b )] and [M{N(R)C(Bu^t)C(H)R}I(PPh₃)] [M = Ni ( 5 a ) or Pd ( 5 b )] have been prepared from a suitable metal halide and lithium precursor of ( 2 ) or ( 3 ) or, alternatively from [M(LL)₂] (M = Ni, LL = cod; M = Pd, LL = dba) and the ketimine RN = C(Bu^t)CH(I)R ( 1 ). All compounds, except 4 were fully characterised, including the provision of X‐ray crystallographic data for complex 5 a .     

Acetylene Dithiolate Linking up the [Tp′W(CO)(CN)] Moiety with RuII or PdII

A series of heterodinuclear complexes with acetylene dithiolate (acdt^2?) as the bridging moiety were synthesised by a facile one‐pot procedure that avoided use of the highly elusive acetylene dithiol. Generation of the W–Ru complex [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] (Tp’=hydrotris(3,5‐dimethylpyrazolyl)borate) and the W–Pd complexes [Tp′W(CN)(CO)(C₂S₂)Pd(dppe)] and [Tp′W(CO)₂(C₂S₂)Pd(dppe)][PF₆] (dppe=1,2‐bis(diphenylphoshino)ethane), which exhibit a [W(η²‐κ²‐C₂S₂)M] core (M=Ru, Pd), was accomplished by using a transition‐metal‐assisted solvolytical removal of the Me₃Si‐ethyl thiol protecting groups. All intermediate species of the reaction have been fully characterised. The highly coloured W–Ru complex [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] shows reversible redox chemistry, as does the prototype complex [Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)][PF₆]. Single crystal X‐ray diffraction and IR, EPR and UV/Vis spectroscopic studies in conjunction with DFT calculations prove the high electronic delocalisation of states over the acdt^2? linker. Comparative studies revealed a higher donor strength and more pronounced dithiolate character of acdt^2? in [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] relative to [Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)]⁺. In addition, the influence of the overall complex charge on the metric parameters was investigated by single‐crystal X‐ray diffraction studies with the W–Pd complexes [Tp′WL₂(C₂S₂)Pd(dppe)] (L=(CN^?)(CO) or (CO)₂). The central [W(C₂S₂)Pd] units exhibit high structural similarity, which indicates the extensive delocalisation of charge over both metals.     

Metal-thiophen derivatives. Organometallic compounds of palladium and platinum

Thienylmercury(II)chloride reacts with [Pd(PPh₃)₂Cl₂], [Pd(PPh₃)₄] and [Pt(PPh₃)₄] to afford new compounds containing a metal-2-thienyl linkage. The compound [Pd(PPh₃)₂(2-C₄H₃S)Cl] probably has trans stereochemistry.2-Bromothiophen undergoes oxidative addition with [Pd(PPh₃)₄] and [Pt(PPh₃)₄], probably via a radical mechanism. With [Pd(CO)(PPh₃)₃], a carbonyl inserted product is obtained. The bromo-metal(II) complexes have trans stereochemistry. The course of the reaction between 3-methyl-2-bromothiophen and Pd(PPh₃)₄ is more complex. Thus, there is evidence of some cis bromopalladium(II) compounds amongst the products, also there is good evidence to support the view that some isomerisation of 3-methyl-2-thienyl to 4-methyl-2-thienyl occurs during the reaction, thus giving greater molar quantities of [Pd(PPh₃)₂(4-CH₃-2-C₄H₂S)Br] than can be accounted for from any initial 4-methyl-2-bromothiophen impurity.The metallation of the thiophen ring, probably in the 4-position, with palladium(II) is described for 3-theylidene-4-methylaniline.     

Sulfur‐assisted Chloride and Triphenylphosphine Dissociation of Palladium(II) Complex with Phenyloxythiocarbonyl,PhOC(S), Containing Ligand: X‐Ray Structure of [Pd(PPh3)2{η1‐C(S)OPh}(Cl)]

Treatment of Pd(PPh₃)₄ with phenylchlorothionoformate, PhOC(S)Cl, in dichloromethane at ?20 °C produces the phenyloxythiocarbonyl complex [Pd(PPh₃)₂{η¹‐C(S)OPh}(Cl)], 1 . The ³¹P{¹H} NMR spectrum of 1 shows the dissociation of either the chloride or the triphenylphosphine ligand to form complex [Pd(PPh₃)₂(η²‐SCOPh)][Cl], 2 or the dipalladium complex [Pd(PPh₃)Cl]₂(μ,η²‐SCOPh)₂, 3 . Continuous stirring of the dichloromethane solution of 1 at room temperature for 4 h forms the dipalladinum complex [Pd(PPh₃)Cl]₂(μ,η²‐SCOPh)₂, 3 as the final product. Respective reactions of 1 and Et₂NCS₂Na or dppa {bis(diphenylphosphino)amine} gives complex [Pd(PPh₃){η¹‐C(S)OPh}(η²‐S₂CNEt₂)], 4 or [Pd(PPh₃){η¹‐C(S)OPh}(η²‐dppa)][Cl], 5 . Complex 1 is determined by single‐crystal X‐ray diffraction and crystallized in the monoclinic space group P2₁ with Z = 4. The cell dimensions of 1 are as follows: a = 9.5613(1) Å, b = 33.6732(3) Å, c = 12.2979(1) Å.     

Synthesis,Reactivity, and Crystal Structure of the η2‐Thiocarbamoyl Palladium Complex [Pd(PPh3)2(η2‐SCNMe2)][PF6]

The η¹‐thiocarbamoyl palladium complexes [Pd(PPh₃)(η¹‐SCNMe₂)(η²‐S₂R)] (R = P(OEt)₂, 2 ; CNEt₂, 3 ) and trans‐[Pd(PPh₃)₂(η¹‐SCNMe₂)(η¹‐Spy)], 4 , (pyS: pyridine‐2‐thionate) are prepared by reacting the η²‐thiocarbamoyl palladium complex [Pd(PPh₃)₂(η²‐SCNMe₂)][PF₆], 1 with (EtO)₂PS₂NH₄, Et₂NCS₂Na, and pySK in methanol at room temperature, respectively. Treatment of 1 with dppm (dppm: bis(diphenylphosphino)methane) in dichloromethane at room temperature gives complex [Pd(PPh₃)(η¹‐SCNMe₂)(η²‐dppm)] [PF₆], 5 . All of the complexes are identified by spectroscopic methods and complex 1 is determined by single‐crystal X‐ray diffraction.