Ph2PCH2CH2P Ph Research Articles

Color change of redox-active organometallic dithienylethene complexes by photochemical and redox processes

Photochromic dithienylethene (DTE) derivatives, DTE–MCpL 2 {M = Fe, Ru; Cp = η 5-cyclopentadienyl; L 2 = (CO) 2, (CO)PPh 3, dppe (dppe = Ph 2PCH 2CH 2PPh 2)}, with a directly σ-bonded, redox-active organometallic attachment have been prepared and their response to photo- and electrochemical stimuli has been investigated. It turns out that the color of the organometallic derivatives can be controlled not only by photochromic processes but also by one-electron redox processes. The Ru complexes 1 Ru and 2 Ru exhibit reversible photochromism in a manner similar to organic DTE derivatives, with ring closing and ring opening triggered by UV and visible-light irradiation, respectively. Their photochromic behavior is critically dependent on both of the central metal and ligands. One-electron oxidation of the Fe complex 3 Fe gives the corresponding radical cationic species with a visible absorption.

Reaction chemistry of tricarbonyl-η 5-pentadienylmanganese: Straightforward synthesis of stable manganese carbonyl terminal thiolates and a dinuclear bis(ethylenediaminyl) complex

Tricarbonyl-η 5-pentadienylmanganese reacts with mercaptans RSH, R = Ph, C 6F 5, m-NH 2C 6H 4, p-NH 2C 6H 4, and HSCH 2CH 2 in the presence of ECH 2CH 2E, E = –PPh 2 or –NH 2 to give novel stable terminal thiolate mononuclear complexes fac-Mn(CO) 3(SR)(Ph 2PCH 2CH 2PPh 2-κ 2- P, P′) for R = Ph, C 6F 5, m-NH 2C 6H 4, p-NH 2C 6H 4, and HSCH 2CH 2 and fac-Mn(CO) 3(SR)(H 2NCH 2CH 2NH 2-κ 2- N, N′) for R = Ph and C 6F 5. Upon reaction of tricarbonyl-η 5-pentadienylmanganese with ethylenediamine a dinuclear complex [ fac-Mn(CO) 3(μ-H 2NCH 2CH 2NH-κ 2- N, N′)] 2 was formed wherein the diaminyl ligand functions in the capacity of chelating and bridging ligand.

Syntheses, structure, and electrochemical properties of homo-metallic binuclear complexes containing ferrocenyl–ethynyl spacers

Structural determinations and electrochemical properties in the series of multinuclear ferrocenyl–ethynyl complexes with formula [( η 5-C 5R 5)(P 2)M II–C C–(fc) n –C C–M II(P 2)( η 5-C 5R 5)] (fc = ferrocenyl; M = Fe(II), Ru(II), Os(II); R = H, CH 3; P 2 = Ph 2PCH 2CH 2PPh 2 (dppe), (C 2H 5) 2PCH 2CH 2P(C 2H 5) 2 (depe)) are reported. Complexes with more electron-rich ligand environment, such as [M( η 5-C 5R 5)P 2] (R = CH 3 and P 2 = dppe, depe), were also prepared with regard to the understanding of electronic coupling mechanism. Structural determinations confirm that the ferrocenyl group is directly linked to the ethynyl linkage which is linked to the pseudo-octahedral [( η 5-C 5R 5)(P 2)M] metal center. These complexes undergo sequential reversible oxidation events from 0.0 to 1.0 V referred to the Ag/AgCl electrode in anhydrous CH 2Cl 2 solution and the low-potential waves have been assigned to the two end-capped metallic centers. The magnitude of the electronic coupling between the two terminal metallic centers in the series of complexes was estimated by the electrochemical technique. Based on the correlation between the Δ E 1/2 values and the second redox potentials of the end-capping metallic centers in the series of complexes, a qualitative explanation for the difference of the electronic coupling is given.

Syntheses of new Mo(II) and W(II) mono(hydrosulfido) complexes and their conversion into di- and tetranuclear sulfido-bridged heterobimetallic complexes

Treatment of [Cp′MH(CO) 3] (M = Mo, W; Cp′ = η 5-C 5H 5 (Cp), η 5-C 5Me 5 (Cp*)) with 1/8 equiv of S 8 in THF, followed by the reaction with dppe under UV irradiation, gave new mono(hydrosulfido) complexes [Cp′M(SH)(CO)(dppe)] (Cp′ = Cp: M = Mo ( 5), W ( 6); Cp′ = Cp*: M = Mo ( 7), W ( 8); dppe = Ph 2PCH 2CH 2PPh 2). When 5 and 6 dissolved in THF were allowed to react with [RhCl(PPh 3) 3] in the presence of base, heterodinuclear complexes with bridging S and dppe ligands [CpM(CO)(μ-S)(μ-dppe)Rh(PPh 3)] (M = Mo ( 9), W( 10)) were obtained. Semi-bridging feature of the CO ligands were also demonstrated. Upon standing in CH 2Cl 2 solutions, 9 and 10 were converted further to the dimerization products [(CpM) 2{Rh(dppe)} 2(μ 2-CO) 2(μ 3-S) 2] (M = Mo ( 13), W). Detailed structures of mononuclear 7 and 8, dinuclear 9 and tetranuclear 13 have been determined by the X-ray diffraction.

Supramolecular architectures constructed on the skeleton of Silver nitrate, 4,4′-bipyridine and triphenylphosphine/1,2-bis(diphenylphosphino)ethane: Synthesis, structural characterization and non-covalent interactions

In the presence of PPh 3 and Ph 2PCH 2CH 2PPh 2 (dppe); AgNO 3 and 4,4′-bipyridine (bpy) react to form [Ag(PPh 3)(bpy) 1/2(ONO 2)] n ( 1) and [Ag(dppe) 1/2(bpy) 1/2(ONO 2)] n ( 2). The compositions of these complexes are supported by their elemental analysis. The structures are determined by spectroscopic (IR, 1H NMR, UV–Vis) and X-ray crystallographic data. A zig-zag ladder type structure observed in 1 changes into straight ladder type structure in 2 in which [Ag(dppe) 1/2(ONO 2)] n chains are bridged by bpy with Ag⋯Ag distance of 11.48 Å. However in 1, the two zig-zag chains are linked via π–π interactions at 3.82 Å between phenyl rings of terminal PPh 3 ligands. Both complexes luminesce in DMSO solution. Photoluminescence of a representative complex 2 is also measured.

Preparation and crystallographic characterization of Pd(II) complexes containing imidobis(diphenylthiophosphinato) ligand

The reactions of PdCI 2(L-L) [L-L = Ph 2PCH 2PPh 2(dppm), Ph 2PCH 2CH 2PPh 2(dppe) and Ph 2PCH 2CH 2CH 2PPh 2(dppp)] with equivalent amount of (Ph 2P(S)NHP(S)Ph 2)(dppaS 2) gave the complexes [Pd(L-L)(dppaS 2-H)]ClO 4 [L-L = dppm ( 1), dppe ( 2), dppp ( 3)]. The different synthetic route was used for complex 2 by using of Pd(dppe)Cl 2 and K[N(PSPh 2) 2] as starting materials ( 2a). All of these complexes have been characterized 31P{ 1H} NMR, IR and elemental analyses. The complexes 2, 2a and 3 were crystallographically characterized. The coordination geometry around the Pd atoms in these complexes distorted square planar. Six membered dppaS 2-H rings are twist boat conformations in three complexes.

Reactivity of mercury(II) halides with the unsymmetrical phosphorus ylide Ph 2PCH 2CH 2PPh 2[dbnd]C(H)C(O)Ph: Crystal structure of {HgI 2[ PPh 2CH 2CH 2PPh 2[dbnd]C(H)C(O)Ph]} n

The unsymmetrical phosphorus ylide, Ph 2PCH 2CH 2PPh 2 C(H)C(O)Ph is shown to react with Hg(II) halides to form polymeric products with the composition {HgX 2[PPh 2CH 2CH 2PPh 2C(H)C(O)Ph]} n , where X = Cl ( 1), Br ( 2), I ( 3). The complexes have been characterized by elemental analysis, IR, 1H, 31P NMR spectra as well as by ESI mass spectra. In product 1 the ylide exhibits a P, C-bridging mode of coordination, while in 2 and 3 it shows a monodentate P-coordination with the dangling ylide. The structure of complex 3 has been characterized crystallographically. The monomeric –Hg–I–Hg– bridging in 3 leads to a zig-zag polymeric chain in which mercury assumes a distorted tetrahedral geometry.

Pyridine- and pyrimidine-2-thiolate complexes of ruthenium

A series of mononuclear ruthenium complexes containing pyridine- and pyrimidine-2-thiolato ligands was prepared and characterized. The new compounds of general formula CpRu(PPh 3)(κ 2 S, N-SR) ( 1) (SR = pyridine-2-thiolate ( a), pyrimidine-2-thiolate ( b)) were prepared directly by reacting the thiolato anions (RS −) with CpRu(PPh 3) 2Cl. Complexes 1 readily react with NOBF 4 or CO in THF at room temperature to give [CpRu(PPh 3)(NO)(κ 1 S-HSR)][BF 4] 2 ( 2) and CpRu(PPh 3)(CO)(κ 1 S-SR) ( 3), respectively. The one-pot reaction of CpRu(PPh 3) 2Cl, thiolato anions and bis(diphenylphosphino)ethane (dppe) gave CpRu(dppe)(κ 1 S-SR) [dppe: Ph 2PCH 2CH 2PPh 2 ( 4)]. The complex salts, [CpRu(PPh 3) 2(κ 1 S-HSR)]BPh 4 ( 5) are prepared by mixing CpRu(PPh 3) 2Cl, HSR and NaBPh 4 at room temperature. The structures of CpRu(PPh 3)(κ 2 S, N-Spy) ( 1a), [CpRu(PPh 3)(NO)(κ 1 S-HSpy)][BF 4] 2 ( 2a) and CpRu(PPh 3)(CO)(κ 1 S-Spy) ( 3a), (py = C 5H 4N) have been determined.

Synthetic studies for the preparation of phosphorus carbonyl rhenacycles with the selenoimidodiphosphinate ligand [N(SePPh 2) 2

The synthesis of the rhenacycles [Re(CO) 3(PR 3){Ph 2P(Se)NP(Se)Ph 2-κ 2 Se}], PR 3 = PPh 3 ( 1), PMePh 2 ( 2), and PMe 2Ph ( 3) by a straightforward high yield procedure is described. Attempts at the preparation of the spiro [Re(CO) 2(Ph 2PCH 2CH 2PPh 2-κ 2P){Ph 2P(Se)NP(Se)Ph 2-κ 2 Se}] resulted in the formation of complexes [Re 2(CO) 6{Ph 2P(Se)NP(Se)Ph 2-κ 2 Se} 2(μ-Ph 2PCH 2CH 2PPh 2)] ( 4) and [Re(CO) 3(Ph 2PCH 2CH 2PPh 2-κ 2P){Ph 2P(Se)NP(Se)Ph 2-κ Se}] ( 5). All new inorganic rhenacycles 1– 5 were characterized in solution and in solid state. The X-ray diffraction analysis of [Re(CO) 3PPh 3{Ph 2P(Se)NP(Se)Ph 2-κ 2 Se}] showed that its MnSePNPSe ring conformation is sensitive to temperature.

Organic–inorganic hybrid matrix doped with alkenyldiazenido complexes of molybdenum

New molecular systems based on conjugated groups, trans-[FMo(NNCHCHCHCHCHCH 2CH 3)(Ph 2PCH 2CH 2PPh 2) 2][BPh 4] have been synthesized and characterized. This complex was immobilized in hybrid organic–inorganic matrix obtained by sol–gel. The hybrid matrix of these organically modified silicates, classified as ureasil formed by poly(oxyethylene) chains [POE, (OCH 2CH 2) n ] grafted to siloxane domains by means of urea cross-linkages. All of the new materials were characterized by thermal analysis (DSC), surface analysis (XPS) and spectroscopic methods (FTIR and UV/vis), to gather information on the modifications introduced by the molybdenum complex in hybrid organic–inorganic matrix, as well as on the immobilized complex integrity. The immobilization of the metal complex in the hybrid matrix has kept their integrity, although some distortions can be observed caused by steric effects imposed by the structure of hybrid matrix or/and by interactions between the metal complex and some groups of the hybrid matrix.

Synthesis and structure of a dmpe-substituted dinuclear complex bridged by a substituent-free gallium atom: Electronic effect of metal fragment on the iron–gallium bonding

A dinuclear complex bridged by a substituent-free gallium atom, Cp ∗(dmpe)Fe–Ga–Fe(CO) 4 ( 1b: Cp ∗ = η-C 5Me 5, dmpe = Me 2PCH 2CH 2PMe 2), was synthesized by the reaction of Cp ∗Fe(dmpe)GaCl 2 with K 2[Fe(CO) 4]. Crystal structure analysis of complex 1b showed that the geometry around the gallium atom is essentially linear and the two Fe–Ga bonds are significantly shorter than those of usual single bonds, indicating the multiple bonding character of the Fe–Ga bonds. Comparison of the structure and IR data of 1b and those of Cp ∗(dppe)Fe–Ga–Fe(CO) 4 ( 1a: dppe = Ph 2PCH 2CH 2PPh 2) revealed that the Fe–Ga bond is sensitive to the electronic character of the metal fragment. The Fe–Ga bond is shortened upon introducing a more π-basic metal fragment.

Synthesis and structure of the diynyl complexes [Mo(C [tbnd]CC [tbnd]CR)L 2(η-C 7H 7)], L 2 = chelate N- or P-donor ligand, R = SiMe 3 or H: X-ray crystal structures of [Mo(C [tbnd]CC [tbnd]CSiMe 3)(2,2′-bipyridine)(η-C 7H 7)] and [Mo(C [tbnd]CC [tbnd]CH)(Ph 2PCH 2CH 2PPh 2)(η-C 7H 7)

The reaction of LiC CC CSiMe 3 with [MoBr( N– N)(η-C 7H 7)] in thf affords the diynyl complexes [Mo(C CC CSiMe 3)( N– N)(η-C 7H 7)], [ 1, N– N = 2,2′-bipyridine (bipy); 2, N– N=1,4- Bu 2 t -1,3-diazabutadiene (Bu t -dab)]; an analogous procedure yields [Mo(C CC CSiMe 3)(CO)(PPh 3)(η-C 7H 7)], 3 starting from [MoBr(CO)(PPh 3)(η-C 7H 7)]. Replacement of bipy in complex 1 with Ph 2PCH 2CH 2PPh 2 (dppe) in refluxing toluene gives [Mo(C CC CSiMe 3)(dppe)(η-C 7H 7)], 4. Proto-desilylation of 2 and 4 leads to formation of the unsubstituted diynyls [Mo(C CC CH)L 2(η-C 7H 7)] ( 5, L 2 = Bu t -dab; 6, L 2 = dppe). Cyclic-voltammetric studies in CH 2Cl 2 reveal that each of complexes 1, 2 and 4– 6 undergo reversible one-electron oxidation processes on the electrochemical time-scale. The X-ray crystal structures of complexes 1 and 6 are reported; the bipyridine complex 1, exhibits a π–π stacking interaction between the bipy ligands of adjacent molecules leading to a head-to-head interaction between diynyl ligands and a resultant substantial bending of the diynyl chain.

Synthesis and structural studies of phosphorus carbonyl manganacycles containing the tetraphenyldiselenoimidodiphosphinato ligand

The [Mn(CO) 4− x (L){Ph 2P(Se)NP(Se)Ph 2-κ 2 Se}] complexes, where x = 1 for L = PPh 3 and PMePh 2, and x = 2 for L = Ph 2PCH 2CH 2PPh 2 (diphos), were synthesized by two routes. The complexes were characterized by IR, mass spectrometry (FAB+), NMR ( 1H, 13C, 31P, 77Se) spectroscopy and/or single crystal X-ray diffraction. The X-ray diffraction analysis for [Mn(CO) 3PMePh 2{Ph 2P(Se)NP(Se)Ph 2-κ 2 Se}] showed that the unit cell contains two independent mononuclear molecules with different MnSePNPSe rings’ conformations.

Reactions of [Fe 3Cp 2(CO) 3(μ-CO)(μ 3-CO)(μ 3-CF 3C 2CF 3)] with diphosphines: X-ray structure of a complex in which two tri-iron clusters are linked only by Ph 2PCH 2CH 2PPh 2

Reactions of the trinuclear iron cluster [Fe 3Cp 2(CO) 3(μ-CO)(μ 3-CO)(μ 3-CF 3C 2CF 3)] ( 1) with the bis(phosphino) ligands dppm and dppe give different results: dppe yields mainly the hexanuclear compound ( 2) in which two tri-iron cluster units are linked by the diphosphine, although a trinuclear derivative ( 3) with a chelating dppe ligand is also obtained as a minor product, whereas dppm displaces carbonyl to give complexes containing exclusively a single tri-iron unit, though the phosphine may be either dangling ( 4) or chelating ( 5). The complexes 2– 5 have been characterised by elemental analyses and from their IR and NMR spectra, supplemented in the case of 2 by a single crystal X-ray diffraction analysis.

Synthesis of the manganese-monocarbollide dianion [1-NHBu t-2,2,2-(CO) 3- closo-2,1-MnCB 10H 10] 2−: Reactions with transition metal cations

Reaction of [Mn(NCMe) 3(CO) 3][PF 6] with Li 3[7-NHBu t - nido-7-CB 10H 10] in THF (THF = tetrahydrofuran) affords the twelve-vertex manganacarborane dianion [1-NHBu t -2,2,2-(CO) 3- closo-2,1-MnCB 10H 10] 2−, isolated as the bis-[N(PPh 3) 2] + salt ( 5a). This species reacts with {Pt(dppe)} 2+ (dppe = Ph 2PCH 2CH 2PPh 2) to afford the bimetallic complex [1-NH 2Bu t -2,3-{Pt(dppe)}-2,2,2-(CO) 3- closo-2,1-MnCB 10H 9] ( 7) which has an Mn–Pt bond. In contrast, with {Cu(PPh 3)} + the anion of 5a yields a CuMnCu trimetallic compound [1-{NH(Bu t )Cu(PPh 3)}-2,3,7-{Cu(PPh 3)}-3,7-(μ-H) 2-2,2,2-(CO) 3- closo-2,1-MnCB 10H 8] ( 8) in which one of the Cu centers is bonded to Mn, whilst the other is attached to the pendant NHBu t group. Upon treatment with Ag +, compound 5a is oxidized giving the very unusual Mn(III)-carbonyl complex [1,2-μ-NHBu t -2,2,2-(CO) 3- closo-2,1-MnCB 10H 10] ( 9a) in which the carborane ligand formally acts as an eight-electron donor to manganese. The novel structural features of compounds 7, 8, and 9a have been confirmed by X-ray diffraction studies.

Synthesis, characterisation, supramolecular aggregation and biological activity of phosphine gold(I) complexes with monoanionic thiourea ligands

A series of phosphine gold(I) complexes containing monoanionic thiourea ligands has been synthesised by reaction of the appropriate precursor chloro complex, Ph 3PAuCl, Cy 3PAuCl, dppf(AuCl) 2 [dppf = Fe(η 5-C 5H 4PPh 2) 2] or dppe(AuCl) 2 (dppe = Ph 2PCH 2CH 2PPh 2) with the thiourea and Me 3N base in methanol solution. The complexes have been fully characterised by elemental analysis, NMR spectrometry, electrospray mass spectrometry, and in several cases, by single-crystal X-ray diffraction studies. The crystallographic studies show that the ligands coordinate as a thiolate in each case with systematic variations in geometric parameters being readily ascribed to the influence of the N-bound substituents. In four of the structures, discernable supramolecular aggregation patterns are evident, leading to loosely associated dimers or chain motifs, the latter mediated by either Au⋯S, N–H⋯N or C–H⋯O interactions. Cytotoxicity data, against the P388 leukemia cell line, and anti-microbial data are also reported.

Synthesis and crystallographic characterization of cationic Pd(II) complexes containing bis(diphenylthiophosphinyl)methane

The reactions of PdCI 2(L-L) [L-L = Ph 2PCH 2PPh 2 (dppm), Ph 2PCH 2CH 2PPh 2 (dppe) and Ph 2PCH 2CH 2CH 2PPh 2 (dppp)] with an equivalent amount of Ph 2P(S)CH 2P(S)Ph 2 (dppmS 2) gave the cationic complexes [Pd(L-L)(dppmS 2)] 2+ which were isolated as perchlorate salts [dppm ( 1), dppe ( 2) and dppp ( 3)]. The complexes 1 and 3 were crystallographically characterized. The coordination geometry around the Pd atoms in these complexes is distorted square planar. Both structures consist of puckered six-membered rings formed by coordination of the disulfide ligands via two sulphur atoms to the metal center. Complex 1 includes one molecule of acetone, [Pd(dppm)(dppmS 2)](ClO 4) 2 · (CH 3) 2CO ( 1a).

The C [dbnd]O and C [dbnd]S bond cleavage in carbon dioxide and tolyl isothiocyanate by reactions with the Mo(0) tetraphosphine complex [Mo{ meso- o-C 6H 4(PPhCH 2CH 2PPh 2) 2}(Ph 2PCH 2CH 2PPh 2)

A Mo(0) complex containing a new tetraphosphine ligand [Mo( P 4 )(dppe)] ( 1; P 4 = meso-o-C 6H 4(PPhCH 2CH 2PPh 2) 2, dppe = Ph 2PCH 2CH 2PPh 2) reacted with CO 2 (1 atm) at 60 °C in benzene to give a Mo(0) carbonyl complex fac-[Mo(CO)(η 3- P 4 O)(dppe)] ( 2), where the O abstraction from CO 2 by one terminal P atom in P 4 takes place to give the dangling P( O)Ph 2 moiety together with the coordinated CO. On the other hand, reaction of 1 with TolNCS (Tol = m-MeC 6H 4) in benzene at 60 °C resulted in the incorporation of three TolNCS molecules to the Mo center, forming a Mo(0) isocyanide–isothiocyanate complex trans, mer-[Mo(TolNC) 2(η 2-TolNCS)(η 3- P 4 S)] ( 4), where the S abstraction occurs from two TolNCS molecules by P 4 and dppe to give the η 3- P 4 S ligand and free dppe S, respectively, together with two coordinated TolNC molecules. The remaining site of the Mo center is occupied by the third TolNCS ligating at the C S bond in an η 2-manner. The X-ray analysis has been undertaken to determine the detailed structures for 2 and 4.

Synthesis and immobilization of molybdenum complexes in a pillared layered clay

New molecular systems based on donor/acceptor groups connected by π-conjugated bridge, trans-[MoF(NNC 7H 6SO 2)(Ph 2PCH 2CH 2PPh 2) 2][BF 4], have been synthesized. This complex with nonlinear optical (NLO) applications was immobilized by an adsorption process from liquid phase, in the interlayer of a pillared clay (PILC). The metal complex and the new materials were characterized by thermal analysis (DSC), chemical analysis, surface techniques (XPS), X-ray powder diffraction (XRD), nitrogen adsorption isotherms, spectroscopic methods (NMR, FT-IR and UV/Vis) and electrochemical measurements. The studies of the electrochemical and the spectroscopic properties of the complex show interactions between donor and acceptor groups across the conjugated bridge. The results obtained from the studies using different techniques of analysis confirm that the molybdenum complex was effectively immobilized in the host matrix and this process does not modify the morphology or structure of the PILC upon metal complex loading.

An electrospray mass spectrometry-directed survey of the coordination chemistry of the metalloligand [Pt 2(μ-S) 2(PPh 3) 4] with platinum(II) and palladium(II) chloride substrates: influence of metal–ligand lability on product type

The reactivity of the metalloligand [Pt 2(μ-S) 2(PPh 3) 4] towards a wide range of platinum(II) and palladium(II) chloride complex substrates [L 2MCl 2] has been explored, using the technique of electrospray ionisation mass spectrometry to directly analyse reaction solutions. In the majority of cases, products are formed by addition of the ML 2 2+ fragment to the {Pt 2S 2} core, giving trinuclear species [Pt 2(μ-S) 2(PPh 3) 4ML 2] 2+. The adducts with Pt(diene) [diene=cyclo-octa-1,5-diene (cod), norbornadiene], Pd(cod), Pd(bipy) (bipy=2,2 ′-bipyridine), Pt(PMe 3) 2 and Pt(PTA) 2 (PTA=phosphatriaza-adamantane) moieties were synthesised and characterised on the macroscopic scale, with [Pt 2(μ-S) 2(PPh 3) 4Pt(cod)] (BF 4) 2 and [Pt 2(μ-S) 2(PPh 3) 4Pd(bipy)] (PF 6) 2 also characterised by X-ray diffraction studies. No metal scrambling was found to occur, as has been observed in some previous cases involving the related complexes [Pt 2(μ-Se) 2(PPh 3) 4] and [Pt 2(μ-S) 2(dppe) 2] (dppe=Ph 2PCH 2CH 2PPh 2). With cis-[PtCl 2(SOMe 2) 2] the species [Pt 2(μ-S) 2(PPh 3) 4PtCl(SOMe 2)] + was formed, as a result of the lability of the SOMe 2 ligand. With palladium(II)-phosphine systems, the observed product species is dependent on the phosphine; the bulky PPh 3 ligand in [PdCl 2(PPh 3) 2] leads primarily to the analogous known species [Pt 2(μ-S) 2(PPh 3) 4PdCl(PPh 3)] +, and a small amount of the metal-scrambled species [PtPd 2S 2(PPh 3) 5Cl] +. In contrast, [PdCl 2(PTA) 2], containing the small PTA ligand gave [Pt 2(μ-S) 2(PPh 3) 4Pd(PTA) 2] 2+.