Synthesis and reactivity towards tetrafluoroboric acid of a new family of heterobimetallic polyhydride complexes [(CO)(PPh3)2HRe(μ-H)3RhL2] (L = PPh3, 1,2,5-triphenylphosphole, or P(OMe)3)

The reaction of K[ReH₆(PPh₃)₂] with [RhCl(CO)L₂] [L= PPh₃, 1,2,5-triphenylphosphole (TPP), or P(OMe)₃] leads to the new electronically unsaturated heterobimetallic polyhydride complexes [(CO)(PPh₃)₂HRe(μ-H)₃RhL₂] in moderate-to-good yields. The structures of these complexes have been established on the basis of spectroscopic data, especially ¹H and ³¹P NMR. The bridging hydride ligands are fluxional but there is either a slow or nonexistent exchange between terminal and bridging hydrides. For L = PPh₃ or TPP, protonation with tetrafluoroboric acid affords quantitatively the cationic complexes [(CO)(PPh₃)₂HRe(μ-H)₃RhHL₂]⁺, isolated as the BF₄⁻ or the BPh₄⁻ salts.     

Arylkomplexe des typs trans-[Ir(Ar)(CO)(PPh3)2]

The preparation and properties as well as some reactions of a series of arylcarbonylbis(triphenylphosphine)iridium(I) complexes [Ir(Ar)(CO)(PPh₃)₂] (Ar = C₆H₅, C₆F₅, 2-C₆H₄CH₃, 3-C₆H₄CH₃, 4-C₆H₄CH₃, 2-C₆H₄OCH₃, 2,6-C₆H₃-(OCH₃)₂, 4-C₆H₄N(CH₃)₂, 3-C₆H₄Cl, 4-C₆H₄Cl, 4-C₆H₄Cl, 3-C₆H₄CF₃, 4-C₆H₄CF₃) are described, and the most important IR data as well as the ³¹P NMR parameters of these, without exception trans-planar, compounds are given.

Some of the complexes react with molecular oxygen to form well defined dioxygen adducts [Ir(Ar)(O₂)(CO)(PPh₃)₂] (Ar = C₆H₅, 3-C₆H₄CH₃, 4-C₆H₄CH₃). Complexes with ortho-substituted aryl ligands are not oxygenated. This effect is referred to as a steric shielding of the metal center by the corresponding ortho-substituents. With SO₂ the similar irreversible addition compound [Ir(4-C₆H₄CH₃)-(SO₂)(CO)(PPh₃)₂] is obtained. Sulfur dioxide insertion into the Ir---C bond cannot be observed.

The first step of the reaction between [Ir(4-C₆H₄CH₃)(CO)(PPh₃)₂] and hydrogen chloride involves an oxidative addition of HCl to give [Ir(H)(Cl)(4-C₆-H₄CH₃)(CO)(PPh₃)₂]. Ir---C bond cleavage by reductive elimination of toluene from the primary adduct does not occur except at elevated temperature.     

Synthesis, structure and hydrogenation catalytic activity of [Ru3(μ3,η-ampy)(μ,η:η-PhC=CHPh)(CO)6(PPh3) (Hampy = 2-amino-6-methylpyridine)

The compound [RU₃(μ₃,η²- -ampy)(μ₃η¹:η²-PhC=CHPh)(CO)₆(PPh₃)₂] (1) (ampy = 2-amino-6-methylpyridinate) has been prepared by reaction of [RU₃(η-H)(μ₃,η²- ampy) (μ,η¹:η²-PhC=CHPh)(CO)₇(PPh₃)] with triphenylphosphine at room temperature. However, the reaction of [RU₃(μ-H)(μ₃, η² -ampy)(CO)₇(PPh₃)₂] with diphenylacetylene requires a higher temperature (110°C) and does not give complex 1 but the phenyl derivative [RU₃(μ₃,η²-ampy)(μ,η ¹:η² -PhC=CHPh)(μ,-PPh₂)(Ph)(CO)₅(PPh₃)] (2). The thermolysis of complex 1 (110°C) also gives complex 2 quantitatively. Both 1 and 2 have been characterized by0 X-ray diffraction methods. Complex 1 is a catalyst precursor for the homogeneous hydrogenation of diphenylacetylene to a mixture of cis- and trans -stilbene under mild conditions (80°C, 1 atm. of H₂), although progressive deactivation of the catalytic species is observed. The dihydride [RU₃(μ-H)₂(μ ₃,η²-ampy)(μ,η¹:η²- PhC=CHPh)(CO)₅(PPh₃)₂] (3), which has been characterized spectroscopically, is an intermediate in the catalytic hydrogenation reaction.     

A localized molecular orbital study on the bonding of> Mo3S4]2Mo> and> Mo3S4]CuI> versus (C6H6)2Cr and C6H6Cr(CO)3

The energy-localized CNDO/2 molecular orbitais have been calculated for the clusters containing molybdenum, > {Mo₃S₄₂Mo}⁸⁺ and> Mo₃S₄]CuI> ⁴⁺, versus the prototype arene-metal sandwich (C₆H₆)₂Cr and half-sandwich complexes C₆H₆Cr(CO)₃. The bonding characteristics of these compounds are described from a localization bonding viewpoint. There are two typical M-arene and M-[Mo₃S₄] bondings. One is formed by electron donation from the three-center two-electron π-bonds in the arene or [Mo₃S₄]⁴⁺ ligands into the vacant hybrid orbitais of the “stranger” metal atom. In the other M-arene or M-[Mo₃S₄] bond there is very little donation by the lone electron pair occupying the d AOs of the “stranger” metal atom to the arene or [Mo₃S₄]⁴⁺ ligands. The analogy of the ligand [Mo₃S₄]⁴⁺ in the clusters studied with the ligand benzene is also briefly discussed.     

The reaction of (μ-H)2Os3(CO)9(PPh3) with ethylene affords the ethylidene complex (μ-H)2Os3(CO)9(PPh3)(μ-CHCH3)

The product isolated from the reaction of (μ-H)₂Os₃(CO)₉(PPh₃) with ethylene is shown to be the ethylidene complex (μ-H)₂Os₃(CO)₉(PPh₃)(μ-CHCH₃) (1) rather than the ethylene complex (μ-H)(H)Os₃(CO)₉(PPh₃)(C₂H₄), as previously claimed. The characterization of 1 is based on a combination of ¹H and ¹³C NMR results. The ¹H NMR data (δ 6.84 (1 H_D), 2.53 (3 H_C), J(CD) = 7.4 Hz) establish the presence of the ethylidene moiety, whereas detailed analysis of the 1-D and 2-D ¹³C NMR spectra of ¹³CO-enriched 1 indicates the relative positions of the ethylidene, hydride, and phosphine ligands on the triosmium framework.     

Ein beitrag zur darstellung und reaktivität der η-allyliridium-komplexe [Ir(η-2-RC3H4) (PPr3)2]

The η³-allyliridium complexes [Ir(η³-2-RC₃H₄)(PⁱPr₃)₂] (2, 3) have been prepared in a one-pot reaction from [IrCl(C₂H₄)₂]₂, 2-RC₃H₄Li and PⁱPr₃ in 70% yield. Compounds 2 and 3 react spontaneously with H₂ to give [IrH₅(PⁱPr₃)₂] (7) and with excess PhC=CH and MeCCH to give [Ir(CCPh)₃(PⁱPr₃)₂] (5) and [Ir(CCMe)₂(CMe=CH₂)(PⁱPr₃)₂] (6), respectively. From 2 (or 3) and two equivalents of PhCCH the complex [IrH(CCPh)₂(PⁱPr₃)₂] (4) has been obtained. Treatment of 2 or 3 with CF₃CO₂H does not lead to a cleavage of the allyl-metal bond but affords the allyl(hydrido)-iridium(III) complexes [IrH(η³-2-RC₃H₄)(η¹-P₂CCF₃)(PⁱPr₃)₂] (8, 9) in almost quantitative yield.     

Preparation and characterization of [Re(bpy)(CO) 3L][SbF6] (L = phosphine, phosphite)

A series of rhenium complexes [fac-Re(bpy)(CO)₃L][SbF₆] (bpy = 2,2′-bipyridine, L = P(ⁿBu)₃, PEt₃, PPh₃, P(OMe)Ph₂, P(OⁱPr)₃, P(OEt)₃, P(OMe)₃, P(OPh)₃) has been prepared and characterized by the IR, UV-vis, ¹H NMR, ³¹P NMR, X-ray photoelectron spectroscopy and electrochemical techniques. Variations in the electronic properties, i.e. CO stretching, metal-to-ligand charge transfer transition, and ³¹P NMR chemical shifts were interpreted on the basis of the electron-acceptor strength of L. However, the redox potential corresponding to [Re(bpy)(CO)₃L]⁺/[Re(bpy⁻)(CO)₃L]showed ‘V-character type’ changes after the increase in the electron-acceptor strength of L. Variation of the P(2p) binding energy of the phosphorus atom indicated that the electronic structure of the coordinated phosphorus atom was strongly influenced by the electronic properties of the directly attached substituents.     

Attempts at stepwise reduction of the carbon-nitrogen triple bond of a nitrile at two metal centres: study of the reactivity of [(CO)(PPh3)2Re( (μ-NCHPh)Ru(PPh3) 2(PhCN)] towards tetrafluoroboric acid and dihydrogen

The reaction of [(CO)PPh₃)₂Re(μ-H)₂(μ-NCHPh)Ru(PPh₃)₂(PhCN)] (2) with HBF₄-Me₂O generates [(CO)PPh₃)₂Re(μ- H)₂(μ,η¹,η²HNCHPh)Ru(PPh₃)₂(PhCN)][BF₄] (3). Monitoring the reaction by NMR spectroscopy shows the intermediate formation of [(CO)(PPh₃)₂ HRe(μ-H)₂(μ-NCHPh)Ru(PPh₃)₂(PhCN)][BF₄] (4). Attempted reduction of the imine ligand by a nucleophile (H⁻ or CN⁻) failed, regenerating 2. Under dihydrogen at 50 atm, 3 is slowly transformed into [(CO)(PPh₃)₂HRe(μ-H)₃Ru(PPh₃)₂(PhCN)][BF₄] (5) with liberation of benzyl amine.     

Synthesis and characterization of hydroxo, pyrazolato and carboxylato derivatives of the PdR(PPh3)moiety (R = C6F5 or C6Cl5)

The hydroxo-complexes [{PdR(PPh₃)(μ-OH)}₂] (R = C₆F₅ or C₆Cl₅) have been obtained by reaction of the corresponding [{PdR(PPh₃)(μ-Cl)}2] complexes with NBu₄OH in acetone. In this solvent, the reaction of the hydroxo-bridged complexes with pyrazole (Hpz) and 3,5-dimethylpyrazole (Hdmpz) in 1:2 molar ratio leads to the formation of the new complexes [{Pd(C₅F₅)(PPh₃)(μ-azolate)}2] and [{Pd(C₆Cl₅)(PPh₃)}₂(μ-OH)(μ-azolate)] (azolate = pz or dmpz). The reaction of the bis(μ-hydroxo) complexes with Hpz and Hdmpz in acetone in 1:1 molar ratio has also been studied, and the resulting product depends on the organic radical (C₆F₅ or C₆Cl₅) as well as the azolate (pz or dmpz). The identity of the isomer obtained has been established in every case by NMR (¹H, ¹⁹F and ³¹P) spectroscopy. The reaction of the bis(μ-hydroxo) complexes with oxalic (H₂Ox) and acetic (HOAc) acids yields the binucle ar complexes [{PdR(PPh₃)}2(μ-Ox)] (R = C₆F₅ or C₆Cl₅) and [{Pd(C₆F₅)(PPh₃)(μ-OAc)}2], respectively. [{Pd(C₆F₅)(PPh₃)(μ-OH)}₂] reacts with PPh₃ in acetone in 1:2 ratio giving the mononuclear complex trans-[Pd(C₆F₅) (OH)(PPh₃)₂], whereas the pentachlorophenylhydroxo complex does not react with PPh₃, even under forcing conditions.     

Molybdenum-molybdenum quadruple bonds: An asymmetrically substituted dimer containing a single acetate bridge. Crystal and molecular structure of [Mo2Cl3(μ-OAc)(PMe3)3]·PhMe

[Mo₂(OAc)₄] reacts with three or more equivalents of lithium chloride and PMe₃ in thf to give [Mo₂Cl₃(μ-OAc)(PMe₃)₃]0.75thf (1). The IR spectrum of the complex shows Mo---O and Mo---Cl stretches at 350 and 300 cm⁻¹ respectively and the ¹H and ¹³C NMR spectra suggest several species are present in solution. [Mo₂Cl₃(μ-OAc)(PMe₃)₃] converts slowly in thf to [Mo₂Cl₄(PMe₃)₄] and [Mo₂(OAc)₄]. The structure of [Mo₂Cl₃(μ-OAc) (PMe₃)₃]0.5C₆H₅Me (2) has been determined by single-crystal X-ray diffraction methods. Crystals of the toluene solvate are tetragonal with a = 20.726(2), c = 11.776(2) Å, space GROUP = I4cm. The structure was solved by Patterson and Fourier methods and refined to R of 0.035 for the 539 observed data. The molecule contains two metal centres each of which shows 5-fold coordination. The two molybdenum atoms are linked by an acetate bridge and a short Mo---Mo bond of 2.121(3) Å. Remaining coordination sites are occupied on Mo(1) by two Cl and one PMe₃ and on Mo(2) by one Cl and two PMe₃ groups.     

Mononuclear Pt(II) and Pd(II) 1,4-dithiolato complexes. Crystal structures of [Pt((−) DIOS) (PPh3)2] and [Pd(S(CH2) 4S)(Ph2P(CH2) 3PPh2)]. Application in styrene hydroformylation

Addition of 1,4-dithiols to dichloromethane solutions of [PtCl₂(P-P)] (P-P = (PPh₃)₂, Ph₂P(CH₂)₃PPh₂, Phd₂P(CH₂)₄PPh₂; 1,4-dithiols = HS(CH₂)₄SH, (−)DIOSH₂ (2,3-O-isopropylidene-1,4-dithiol-l-threitol), BINASH₂ (1,1′-dinaphthalene-2,2′-dithiol)) in the presence of NEt₃ yielded the mononuclear complexes [Pt(1,4-dithiolato)(P-P)]. Related palladium(II) complexes [Pd(dithiolato)(P-P)] (P-P=Ph₂P(CH₂)₃PPh₂, Ph₂P(CH₂)₄PPh₂; dithiolato = ⁻S(CH₂)₄S⁻, (−)-DIOS) were prepared by the same method. The structure of [Pt((−)DIOS)(PPh₃)₂] and [Pd(S(CH₂)₄S)(Ph₂P(CH₂)₃PPh₂)] complexes was determined by X-ray diffraction methods. Pt—dithiolato—SnC1₂ systems are active in the hydroformylation of styrene. At 100 atm and 125°C [Pt(dithiolate)(P-P)]/SnCl₂ (Pt:Sn = 20) systems provided aldehyde conversion up to 80%.     

Synthesis and X-ray crystal structures of [Ru4H4(CO) 11(PPh3)] and [Ru4−x IrxH2−x(CO) 12(PPh3) ] (x = 0 or 1)

Three tetranuclear clusters [Ru₄H₄(CO)₁₁(PPh₃)] (1), [Ru₄H₂(CO)₁₂(PPh₃)] (2) and [Ru₃IrH(CO)₁₂(PPh₃)] (3) were formed in the reaction of [Ir(CO)Cl(PPh₃)₂] and Na[Ru₃H(CO)₁₁] in tetrahydrofuran. Complexes 1–3 were characterized by IR and ¹H and ³¹P NMR, and the structure of the clusters was confirmed by single crystal X-ray analysis. In 2 and 3 one of the carbonyls bridges between two ruthenium atoms; otherwise the compounds contain only terminal carbonyls.     

Heterobimetallic Mo---Sn complexes. Reactions of [Mo(CO)3(CH3CN)2(Cl)(SnRCl2)] (R = Me, Ph) with 4(4-XC6H4)3 (X = Cl, F, H, Me, MeO)

Three families of heterobimetallic compounds were obtained by reaction of [Mo(CO)₃(CH₃CN)₂(Cl)(SnRCl₂)] (R = Ph, Me) with P(4-XC₆H₄)₃ (X = Cl, F, H, Me, MeO). The type of compound obtained dependent on the solvent and concentration of the starting compound. So, [Mo(CO)₂(CH₃COCH₃)₂(PPh₃)(Cl)(SnRCl₂)]·nCH₃COCH₃ (R = Ph, n = 0.5; R = Me, n = 1) (type I) and [Mo(CO)₃{P(4-XC₆H₄)₃}(μ-Cl)(SnRCl₂)]₂ (R = Ph, X = Cl, F, H, Me, MeO; R = Me, X = Cl, F) (type II) were isolated from acetone solution in ca 0.05 M and 0.1 M concentrations, respectively. However, [Mo(CO)₃(CH₃CN) {P(4-XC₆H₄)₃}(Cl)(SnRCl₂)] (R = Ph, X = H; R = Me, X = Cl, F, H) (type III) were obtained from dichloromethane solution independently of the concentration used. All new complexes showed a seven-coordinate environment at molybdenum, containing Mo---Cl and Mo---Sn bonds. Mössbauer spectra indicated a four-coordination at tin for type III complexes.     

Electrochemical studies on Mo2Cl4(PR3)4 compounds containing phosphines of varied basicity

The electrochemical behaviour of a series of Mo₂Cl₄(PR₃)₄ complexes (PR₃ = PMe₃, PEt₃, PPrⁿ₃,PBuⁿ₃, PH₂Ph, PMe₂Ph, PEt₂Ph, PHPh₂, PMePh₂, PEtPh₂, P(OMe)₃, P(OMe)Ph₂) has been examined by cyclic voltammetry in dichloromethane solution. The phosphines were chosen to provide a wide range of Lewis basicity/π acidity as reflected by Tolman's _co IR and Bodner's Δδ_co ¹³C NMR spectral parameters for Ni(CO)₃(PR₃). The Mo₂ compounds undergo either quasi-reversible or irreversible one-electron oxidations except for P(OMe)₃ and P(OMe)Ph₂ for which no clectroactivity was observed before the solvent limit. The anodic peak potentials, E_p,a, span a range of nearly 700 mV. The half-wave potentials, E_1/2,for the quasi-reversible couples and E_p,a for all were plotted against the IR and NMR values and against the δ → δ* transition energies for the Mo₂ species in dichloromethane and in the solid state. For the organometallic spectral parameters excellent linear correlations were obtained while with the electronic spectral data fair correlations resulted. These results indicate that the Mo₂Cl₄(PR₃)₄ complexes become more difficult to oxidize as the electron-withdrawing nature of the PR₃ substituents increases and the δ → δ* band energy decreases.     

Syntheses and X-ray crystal structures of [Co(η-CO3)(NH3)4](NO3)·0.5H2O and [(NH3)3Co(μ-OH)2(μ-CO3)Co(NH3)3][NO3]2·H2O

[Co(η²-CO₃)(NH₃)₄](NO₃)·0.5H₂O and [(NH₃)₃Co(μ-OH)₂(μ-CO₃)Co(NH₃)₃][NO₃]₂·H₂O were prepared by prolonged aerial oxidation of a solution of Co(NO₃)₂·6H₂O and ammonium carbonate in aqueous ammonia. The formation of these side products highlights the richness of the chemistry of these systems and the possibility of by products if methods are not strictly adhered to. The X-ray crystal structures of [Co(η²-CO₃)(NH₃)₄][NO₃]·0.5H₂O and [(NH₃)₃Co(μ-OH)₂(μ-CO₃)Co(NH₃)₃][NO₃]₂·H₂O reveal a monomeric octahedral cobalt center with η²-bound CO₃²⁻ in the former, while the latter consists of a dimeric array where the two cobalt centers are bridged by two OH⁻ and one μ₂-CO₃²⁻ groups with three terminal NH₃ ligands for each Co center. In both complexes extensive hydrogen bonding interactions are evident.     

Synthesis and characterization of cationic heteronuclear complexes of platinum(II) and silver( I) bridged by alkynyl ligands

The dialkynyl complexes cis-[Pt(C CR)₂L₂] [R = Ph, L₂ = 2PPh₃, 2PEt₃, dppe (dppe = 1,2-bis(diphenylphosphino)ethane]; R ---^tBu, L₂ = 2PPh₃, dppe) react with silver perchlorate in a molar ratio 1:0.5 to give platinum-silver perchlorate salts of the type [Pt₂ Ag(C CR)₄L₄](ClO₄) in excellent yield. The X-ray crystal structure of [Pt₂Ag(C = CPh)₄(PPh₃)₄](ClO₄) 1 shows that the cation is formed by two nearly orthogonal cis-[Pt(C CPh)₂(PPh₃)₂] units connected through a silver cation which is unsymmetrically π-bonded to all four acetylene fragments. Similar reactions of cis-[Pt(C CR)₂L₂] with one equivalent of AgClO₄ afford cationic complexes of general formula [PtAg(C CR)₂L₂](ClO₄), which are believed to be salts, [Pt₂Ag₂(C CR)₄L₄](ClO₄)₂.     

Copper thioether chemistry: The synthesis and single crystal X-ray structures of [Cu2([18]aneS6)(NCMe)2](ClO4)2 and [Cu([9]aneS3)(AsPPh3)](ClO4)

Reaction of [18]aneS₆ with two molar equivalents of [Cu(NCMe)₄](ClO₄) in CH₂Cl₂-MeCN affords the binuclear copper(I) complex [Cu₂([18]aneS₆)(NCMe)₂](ClO₄)₂. The single crystal X-ray structure of the complex shows a centrosymmetric cation with two tetrahedral copper(I) centres each coordinated to three thioether S-donors of [18]aneS₆,Cu---S(1) = 2.3200(15), Cu---S(4) = 2.3415(16), Cu---S(7) = 2.3250(15) Å, and to one MeCN molecule, Cu---N(1) = 1.939(5) Å, to give an overall NS₃-donation at the metal centres. Additionally, S(7′) shows a long-range interaction, Cu …S(7′) = 3.318(2) Å thus distorting the coordination geometry of the metal ion towards trigonal bipyramidal. The metal-metal separation of 4.428(2) Å suggests that there is no significant interaction between the copper centres of the dimer. Reaction of [9]aneS₃ with one molar equivalent of [Cu(NCMe)₄](ClO₄) in refluxing MeCN in the presence of ligands, L, affords the adducts [Cu([9]aneS₃)L]⁺ (L = PPh₃, AsPh₃). The single crystal X-ray structure of the complex [Cu([9]aneS₃)(AsPh₃)](ClO₄) shows tetrahedral AsS₃ coordination at copper(I) with [9]aneS₃ bound facially to the metal centre, Cu---S = 2.303(6), Cu---As = 2.322(4) Å.     

Synthesis, characterization and the unpleasantly disordered crystal structure of Ir(Ome)(CO)(PPh3)2(SO4)

The adducts of O₂ and SO₂ with trans-MeOIr(CO)(PPh₃)₂ are formed in equilibria and have been characterized. Reaction of the SO₂ adduct, Ir(OMe)(SO₂)(CO)(PPh₃)₂ with dioxygen leads to the sulfato complex, Ir(Ome)(CO)(PPh₃)₂(SO₄), the structure of which has been determined. Ir(Ome)(CO)(PPh₃)₂(SO₄) crystallizes in the monoclinic system with a 11.958(2), b 14.163(3), c 12.231(2) Å, β 118.365(12)°, V 1822.7(6) ų and Z = 2. Diffraction data for 2θ = 4.5–45.0° (Mo-K) were collected with a Syntex P2₁ diffractometer and the structure was solved (assuming space group P2₁/m and an unpleasant 2-fold disordered model) and refined to R = 4.8% for all 2512 independent data (R = 3.5% for those 2042 data with ¦F_O¦ > 6σ(¦F¦)). The iridium(III) atom has a distorted octahedral coordination sphere with trans PPh₃ ligands and a cis-chelating bidentate O,O′-SO₄ group; the structure is completed by mutually cis OMe and CO ligands.     

Oxygen abstraction from tetrahydrofuran by molybdenum-iodide complexes. X-ray molecular structure of [Mo2(μ-O)(μ-I)(μ-O2CCH3)I2(THF)4][MoOI4(THF)] (THF = tetrahydrofuran)

The interaction between Mo₂(O₂CCH₃)₄, Me₃SiI and I₂ in THF resulted in oxygen abstraction from the solvent and formation of [Mo₂(μ-O)(μ-I)(μ-O₂CCH₃) I₂(THF)₄]⁺[MoOI₄(THF)]⁻ and I---(CH₂)₄---I. The molybdenum complex has been characterized by X-ray diffractometry. Crystal data: triclinic, space group P , a = 13.827(3) Å; b = 15.803(7) Å; c = 9.950(3) Å; = 93.34(4)°; β = 102.40(2)°; γ = 90.09(2)°; V = 2120(2) Å₃; Z = 2; d_calc = 2.559 g cm⁻³; R = 0.0476 (R_w = 0.0613) for 370 parameters and 3938 data with F₀²> 3σ(F₀²). The metal-metal distance in the cation is 2.527(2) Å and indicates a strong interaction. The magnetic behavior is consistent with the assignment of one unpaired electron to the Mo₂⁷⁺ core of the cation and one to the d¹ Mo(V) center of the anion. The interaction between Mo(CO)₆ and I₂ in THF also results in the formation of 1,4-diiodobutane.     

Preparation and X-ray crystal structures of mixed ligand complexes containing the S3N ligand

Reaction of Hg(S₇N)₂ with cis- PtCl₂(PR₃)₂ (PR₃ = PPh₃, PPh₂Me, PPHMe₂, PEt₃) in the presence of Na[PF₆] gives [Pt(S₃N)(PR₃)₂][PF₆] in 32–46% yield. The complexes have been characterized by IR, NMR and microanalyses. The X-ray crystal structures of two examples (PR₃ = PPh₂Me and PEt₃) show that the S₃N⁻ ligand coordinates in a bidentate fashion via two sulphur atoms.