Die Kristallstruktur von (PPh4)2[Mo2(O2C?Ph)4Br2] · 2 CH2Br2

Crystal Structure of (PPh₄)₂[Mo₂(O₂C? Ph)₄Br₂] · 2 CH₂Br₂ The title compound, prepared by the reaction of Mo₂(O₂C? Ph)₄ with PPh₄Br and PPh₄N₃, respectively, under the assistance of CH₂Br₂, was characterized by an X-ray structure determination. Space group P2₁/n, Z = 2, R = 0.074 (5261 independent observed reflexions). The lattice dimensions are at ?70°C: a = 1562.9, b = 1406.2, c = 1662.1 pm, β = 94.11°. the compound consists of PPh₄^⊕ ions, CH₂Br₂ molecules, and centrosymmetric anions [Mo₂(O₂C? Ph)₄Br₂]^2?. The axis Br? Mo?Mo–Br is nearly linear (bond angle 175.6°) with bond lengths MoMo = 212.3 pm and Mo? Br = 303 pm, corresponding with a weak electrostatic Mo? Br bond. In the FIR spectrum the Mobr stretching vibration is found at 85 cm^?1, which corresponds with the low value of the force constant of 0.24 N · cm^?1.     

High Intensity Trip-Multiplet Transitions,a Reality! Synthesis,Properties, and Crystal Structure of l-Bis(triphenylphosphine)iminium trans-Dibromophthalocyaninato(2–)molybdate(III)

Oxophthalocyaninato(2–)molybdenum(IV), activated by bromine oxidation prior to use, reacts with fused triphenylphosphine in the presence of bis(triphenylphosphine)iminium bromide to yield linear-bis(triphenylphosphine)iminium trans-dibromophthalocyaninato(2–)molybdate(III), ^l(PNP)^trans[Mo(Br)₂pc^2?]. It crystallizes triclinic with crystal data: a = 10.506(1) Å, b = 12.436(2) Å, c = 12.918(2) Å, α = 76.186(1)°, β = 67.890(1)°, γ = 68.689(1)°; space group P1 (No. 2); Z = 1. Mo^III is in a pseudo-octahedral coordination geometry with the bromo ligands in trans-arrangement. The Mo? N_p and Mo? Br distance is 2.043(10) and 2.588(1) Å, respectively. The PNP cation adopts a linear conformation. In the IR spectrum v_as(Mo? Br) is observed at 218 cm^?1 and v_as(P? N) of the linear (P? N? P) core at 1406 cm^?1. Cyclic and differential-pulse voltammetry show two quasi-reversible cathodic processes at ?1.15 and ?0.53 V vs. Ag/AgCl. The first is assigned to a phthalocyaninate directed reduction (pc^2?/pc^3?), while the latter arises from a Mo directed reduction (Mo^III/Mo^II). Spectral monitoring confirms the reversible Mo^III/Mo^II reduction. Two quasi-reversible anodic processes at 0.60 and 1.27 V are assigned to the successive Mo directed oxidation with redox couples Mo^III/Mo^IV and Mo^IV/Mo^V. For the first time, three very intense spin-allowed trip-quartet transitions are observed in the electronic absorption spectra at 7140 (TQI), 16890 (TQ2) and 18700 cm^?1 (TQ3) together with a sing-quartet transition at 15850 cm^?1 and characteristic ?Q”? region with maximum at 28500 cm^?1 and ?N”? region at 37400 cm^?1. All electronic excitations are of comparable intensity. A prominent low temperature emission at 6690 cm^?1 is assigned to a spin-forbidden trip-sextet.     

Darstellung von trans-[Mo6Cl8]Cl4Br22−ausgehend von kristallisierten [Mo6Cl8]Cl4(H2O)2 und die Kristallstruktur von [(C6H5)4As]2[Mo6Cl8]Cl4Br2

Preparation of trans-[Mo₆Cl₈]Cl₄Br₂^2? Starting from Crystalline [Mo₆Cl₈]Cl₄(H₂O)₂ and Crystal Structure of [(C₆H₅)₄As]₂[Mo₆Cl₈]Cl₄Br₂ The synthesis of the title compound is successful if the crystallized [(Mo₆Cl₈)Cl₄(H₂O)₂] containing the H₂O molecules in trans-position reacts with HBr + [(C₆H₅)₄As]Br in ethanol in a heterogeneous reaction. The X-ray structure investigation confirms the existence of discrete trans-Br-substituted cluster anions of composition [(Mo₆Cl₈)Cl₄Br₂]^2? in the crystal. The reaction in homogeneous solutions proceeds to Br-enriched compounds. [(C₆H₅)₄As]₂[(Mo₆Cl₈)Cl₄Br₂] crystallizes in the triclinic space group P¯1 with a = 11.071(2), b = 11.418(2), c = 12.813(2) Å, α = 116.10(2), β = 95.27(2) and γ = 94.41(2)° (?133°C). The crystal structure at ?133°C was determined from single crystal X-ray diffraction data (R₁ = 0.026). The [(Mo₆Cl₈)Cl₄Br₂]^2?-anions are not completely ordered but distributed statistically among the three positions which are possible within the limits of the ordered [Mo₆Cl₈]-cores (ratio 11:5:4). The frameworks of the anions consist of Mo₆ cluster units with (slightly distorted) octahedral arrangement of the metal atoms (d(Mo? Mo): 2.600(1) up to 2.614(1) Å), which are coordinated by the halogeno ligands in a square-pyramidal manner. The details of the structure will be discussed and compared with similar [(Mo₆X₈)Y₄] cluster units (X, Y ? Cl, Br).     

The crystal structure of (NH4)2[Mo2(S2)6].8/3H2

The black crystal of (NH₄)[Mo₂(S₂)₆]* 8/3 H₂O belongs to the orthorhombic system, space group D³₂-P22₁2₁, with a = 12.064(6), b = 12.534(4), c = 19.558(9)Å, V =2957(3)ų, Z = 4 and D_c = 2.23g.cm^?3. The intensity data were collected on a Syntex R3 four-circle diffractometer. The structure was solved by Patterson method and direct method, the light atoms (except H atoms) were obtained from ΔF syntheses. The structure was refined by least-squares with anisotropic thermal parameters. The values of R and R_w were 0.092 and 0.072 respectively. The crystal structure contains discrete dimeric cluster [Mo₂(S₂)₆]^2? ions, NH₄⁺ cations and H₂O molecules. There are two crystallographically independent [Mo₂S₂)₆]^2? ions in the crystal, one locates on general position [Figure 1(a)], the other locates on two-fold axis [Figure 1(b)]. It contains one and a half [Mo₂S₂)₆]^2? ions in an asymmetric unit. In [Mo₂S₂)₆]^2? each Mo is coordinated side on by four S₂^2? groups in a distorted dodecahedral arrangement, two of which are bridging and the other two are terminal. The Mo? S bond length is 2.441 Å (mean), and S? S is 2.049 Å (mean). The Mo? Mo distance is 2.784 Å (mean), which is to be regarded as a single bond length. The formal oxidation state of Mo is five, it is probably a mixed valence Mo^IV? Mo^VI, and so shows a remarkable deep colour.     

Synthesis and structure of an open-type trinuclear molybdenum cluster compound[Mo_3(μ_3-S)(μ-S)_2-(μ-OAc)(S_2CNC_4H_8)_3(O)_2]·0.5CH_2Cl_2·2H_2O

The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2]with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)-(S_2CNC_4H_8)_3(O)_2]·0.5CH_2CI_2·2H_2O,Mr=980.18,triclinic,space group P,α=12.360(3),b=16.653(6),c=9.206(2)A,α=101.97(2),β=108.32(2),γ=86.14(3)°.V=1759.6(9)A~3,Z=2,Dc=1.85 g/cm~3,F(000)=962,μ(Mo K_α)=16.53 cm~(-1).Final R=0.044 for 4301 reflections with I≥3σ(I).This compoundmay be regarded as a mixed-valent trinuclear molybdenum cluster{Mo_2(V)Mo(Ⅳ)(μ_3-S)(μ-S)_2-(μ-OAc)(S_2CNC_4H_8)_3(O)_2}.The Mo-Mo distances are 2.783(1),2.833(1)and 3.374(2)A in the Mo_3non-equilateral triangle and there exist only two Mo-Mo bonds.The cluster was obtained by oxi-dation and ligand substitution of{Mo_3(μ_3-S)(μ-S)_3[μ-S_2P(OEt_2)][S_2P(OEt)_2]_3(H_2O)}.     

Synthesis of cis-Tetrabromobispyridinemolybdates(III) and the crystal structure of cis-(NH4)[MoBr4py2] · ⅓3 H2O (py = pyridine)

The reaction between (NH₄)[MoBr₅ · H₂O] and pyridine in acetonitrile (CH₃CN) at room temperature results in the mixture of cis- and trans-(pyH)[MoBr₄py₂] which can be separated on the basis of solubility. cis-M[MoBr₄py₂] · ? H₂O (M = NH₄⁺, Rb⁺, Cs⁺), cis-(bipyH)[MoBr₄py₂] (bipy = 2,2′-bipyridil) and cis-(PPh₄)[MoBr₄py₂], were prepared from cis-(pyH)[MoBr₄py₂]. At the temperature of boiling acetonitrile irreversible cis to trans isomerisation takes place. Bromine oxydizes cis isomers at room temperature to trans-MoBr₄py₂. The compounds were characterised by chemical analysis, infrared, UV-VIS spectroscopy, conductivity measurements and powder diffraction. The crystal structure of cis-(NH₄)[MoBr₄py₂] · ? H₂O has been determined: rhombohedral, R3c, (No. 161), a = 15.809(3) Å, β = 112.79(2)°, Z = 6, D_C = 2.29, D_O = 2.27(3) g/cm³, V = 2 601(1) ų, R₁ = 0.046, R_w = 0.068. Average Mo? Br and Mo? N(pyridine) distances within the anion are 2.58(2) and 2.20(2) Å. cis-Rb[MoBr₄py₂] · ? H₂O and cis-Cs[MoBr₄py₂] · ? H₂O are isostructural with cis-(NH₄)[MoBr₄py₂] · ? H₂O.     

Reactions of Hexanuclear Niobium and Tantalum Halide Clusters with Mercury(II) Halides. I. Synthesis and structures of the semiconducting compounds [M6Br12(H2O)6][HgBr4] · 12H2O,MNb,Ta

A method for the preparation of new solvated clusters of the composition [M₆Br₁₂(H₂O)₆][HgBr₂X₂] · 12H₂O (M?Nb, Ta; X?Cl, Br, I) is given. The cubic crystals of [Nb₆Br₁₂(H₂O)₆][HgBr₄] · 12H₂O 1 and [Ta₆Br₁₂(H₂O)₆][HgBr₄] · 12H₂O 2 were characterized by the X-ray structure analysis: 1 : cubic, space group Fd3 m, a = 21.0072(6) Å, Z = 8, R = 0.051 (R_w = 0.066); 2 : cubic, space group Fd3 m, a = 20.9698(1) Å, Z = 8, R = 0.038 (R_w = 0.050). 1 and 2 contain octahedral cluster cation [M₆Br₁₂(H₂O)₆]²⁺ and tetrahedrally arranged [HgBr₄]^2? anion. The M? M bond distances are 2.949(1) Å for 1 and 2.9000(8) Å for 2 . The Hg? Br bond distances in [HgBr₄]^2? anion are 2.614(2) Å in 1 and 2.622(2) Å in 2 . The crystal packing patterns of the isostructural clusters 1 and 2 involve the three-dimensional hydrogen bond network; the crystalline water molecules act as donors of hydrogen to the bromine atoms of the cluster and [HgBr₄]^2? units, whereas the coordinated water molecules form hydrogen bonds to the crystalline water molecules. [Nb₆Br₁₂(H₂O)₆][HgBr₄] · 12H₂O is diamagnetic and semiconducting with the activation energy, E_a = 0.20 eV.     

The Cocrystallization of the Cubic [Ta6Br12(H2O)6][CuBr2X2]·10H2O and Triclinic [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl,Br, NO3) Phases with the Coexistence of [Ta6Br12]2+ and [Ta6Br12]4+ in the Latter

Cubic [Ta₆Br₁₂(H₂O)₆][CuBr₂X₂]·10H₂O and triclinic [Ta₆Br₁₂(H₂O)₆]X₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O (X = Cl, Br, NO₃) cocrystallize in aqueous solutions of [Ta₆Br₁₂]²⁺ in the presence of Cu²⁺ ions. The crystal structures of [Ta₆Br₁₂(H₂O)₆]Cl₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 1 ) and [Ta₆Br₁₂(H₂O)₆]Br₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 3 )have been solved in the triclinic space group P&1macr; (No. 2). Crystal data: 1 , a = 9.3264(2) Å, b = 9.8272(2) Å, c = 19.0158(4) Å, α = 80.931(1)?, β = 81.772(2)?, γ = 80.691(1)?; 3 , a = 9.3399(2) Å, b = 9.8796(2) Å, c = 19.0494(4) Å; α = 81.037(1)?, β = 81.808(1)?, γ = 80.736(1)?. 1 and 3 consist of two octahedral differently charged cluster entities, [Ta₆Br₁₂]²⁺ in the [Ta₆Br₁₂(H₂O)₆]²⁺ cation and [Ta₆Br₁₂]⁴⁺ in trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]. Average bond distances in the [Ta₆Br₁₂(H₂O)₆]²⁺ cations: 1 , Ta‐Ta, 2.9243 Å; Ta‐Brⁱ , 2.607 Å; Ta‐O, 2.23 Å; 3 , Ta‐Ta, 2.9162 Å; Ta‐Brⁱ , 2.603 Å; Ta‐O, 2.24 Å. Average bond distances in trans‐[Ta₆‐Br₁₂(OH)₄(H₂O)₂]: 1 , Ta‐Ta, 3.0133 Å; Ta‐Brⁱ, 2.586 Å; Ta‐O(OH), 2.14 Å; Ta‐O(H₂O), 2.258(9) Å; 3 , Ta‐Ta, 3.0113 Å; Ta‐Brⁱ, 2.580 Å; Ta‐O(OH), 2.11 Å; Ta‐O(H₂O), 2.23(1) Å. The crystal packing results in short O···O contacts along the c axes. Under the same experimental conditions, [Ta₆Cl₁₂]²⁺ oxidized to [Ta₆Cl₁₂]⁴⁺ , whereas [Nb₆X₁₂]²⁺ clusters were not affected by the Cu²⁺ ion.     

The synthesis and crystal structure of a trinuclear molybdenum cluster compound [Mo3(μ-O)(μ-S)3(μ(μ-OAc)2(dtp)2·(Py)]·0.5H2O

[Mo₃,OS₃(dtp)₄(H₂O)] reacts with NaOAc·3H₂O in Py to give the title compound. The crystal data are as follows: [Mo₂OS₃)(OAc)₂(dtp)₂·Py]?0.5H,O(dtp = [S₃P(OC₂H₅)₂]^?, Py = C₅H₅N); M = 976.64; triclinic; space group P1 ; a=11.704(5), b=14.169(7), c= 11.688 (5) Å α=109.94(4) β = 91.53(4), γ = 91.93(4)°; V= 1819(1) Ų; Z=2; D_c = 1.78 g·cm^?3 λ(Mo Kα) = 0.71069 Å μ=15.15 cm^?1; F(000) = 970 T=296 K; final R=0.071 for 1652 reflections with I>3σ(I). In the molecule, the [Mo₃OS₃] core is surrounded by two bridging OAc groups and two terminal chelate dtp groups attached to the {Mo₃} triangle in a symmetric style, and the Py ligand is coordinated to the Mo atom at the apex of {Mo₃} triangle with the nitrogen. This novel configuration is obtained for the first time with Mo—N bond length being 2.27 (2) Å and three Mo—Mo bond lengths 2.584 (4), 2.587 (4) and 2.657(4) Å, respectively. As a whole, the molecule has a virtual C₂ symmetry.     

Molybdänhalogenidcluster mit sechs terminalen Alkoholatliganden: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH und (C18H36N2O6Na2)2[Mo6Cl8(OC6H5)6]

Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6CH₃OH and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] . The reaction of Na₂[Mo₆Cl₈(OCH₃)₆] and 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6 CH₃OH ( 1 ), which is converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo₆Cl₈ⁱ(OR^a)₆]^2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo₆Cl₈(OC₆H₅)₆]^2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.     

Molybdänhalogenidcluster mit zwei terminalen Alkoholatliganden: Synthese und Kristallstrukturen von (C18H36N2O6Na)2[Mo6Cl12(OCH3)2] und (C18H36N2O6Na)2[Mo6Cl12(OC15H11)2] · 2C4H6O3

Molybdenum(II) Halide Clusters with two Alcoholate Ligands: Syntheses and Crystal Structures of (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ . Reaction of Mo₆Cl₁₂ with two equivalents of sodium methoxide in the presence of 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] ( 1 ), which can be converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ ( 2 ) by metathesis with 9-Anthracenemethanole in propylene carbonate. As confirmed by X-ray single crystal structure determination ( 1 : C2/m, a=25.513(8) Å, b=13.001(3) Å, c=10.128(3) Å, β=100.204(12)°; : C2/c, a=15.580(5) Å, b=22.337(5) Å, c=27.143(8) Å, β=98.756(10)°) the compounds contain anionic cluster units [Mo₆ClCl(OR^a)₂]^2? with two alcoholate ligands in terminal trans positions ( 1 : d(Mo—Mo) 2.597(2) Å to 2.610(2) Å, d(Mo—Clⁱ) 2.471(3) Å to 2.493(4) Å, d(Mo—Cl^a) 2.417(8) Å and 2.427(8) Å, d(Mo—O) 2.006(13) Å; 2 : d(Mo—Mo) 2.599(3) Å to 2.628(3), d(Mo—Clⁱ) 2.468(8) Å to 2.506(7) Å, d(Mo—Cl^a) 2.444(8) Å and 2.445(7) Å, d(Mo—O) 2.012(19) Å).     

Thiokomplexe des Molybdäns Kristallstruktur eines Mischkristalls (PPh3Me)2[Mo2Br6(NO)4]/(PPh3Me)2[Mo2Br6S2(NO)2]

Thiocomplexes of Molybdenum. Crystal Structure of a Mixed Single Crystal (PPh₃Me)₂[Mo₂Br₆(NO)₄]/(PPh₃Me)₂[Mo₂Br₆S₂(NO)₂] The reactions of (PPh₄)₂MoS₄ with MoBr₄ and MoBr₂(NO)₂ resp. lead to the binuclear complexes (PPh₄)₂[S₂MoS₂MoBr₃(SMe₂)] and (PPh₄)[S₂MoS₂MoBr₂(NO)₂], in which the molybdenum atoms are linked by sulfido bridges. The preparation of (PPh₃Me)₂S₆ and (AsPh₄)₂S₇ from Na₂S₄ and PPh₃MeBr, and AsPh₄Cl, respectively, in ethanol solution is described. Disulfido briges are a feature of (AsPh₄)₂[Mo₂Br₆(S₂)₂(SMe₂)₂], which is obtained from MoBr₄(SMe₂)₂ and (AsPh₄)₂S₇. Mixed single crystals containing 2/3 (PPh₃Me)₂[Mo₂Br₆(NO)₄] and 1/3 (PPh₃Me)₂[Mo₂Br₆S₂(NO)₂] are formed in the reaction of MoBr₂(NO)₂ with (PPh₃Me)₂S₆, as shown by X-ray single crystal structure determination. The compound crystallizes monoclinic in the space group C2/c (Internat. Tab. Nr. 15) with four formula units per unit cell (2351 independent observed reflexions, R_w = 0.037). The cell parameters are a = 1603 pm, b = 1549 pm, c = 1863 pm; β = 92.2°. The complexes consist of PPh₃Me^⊕ cations and the dimeric anions [Mo₂Br₆(NO)₄]^2? and [Mo₂Br₆S₂(NO)₂]^2? which occur in the ratio 2:1. In these the molybdenum atoms are connected via MoBr₂Mo bridges of slightly different lengths (Mo? Br 265 pm and 267 pm) forming a controsymmetric double octahedron. All molybdenum atoms have two terminal bromo ligands with Mo? Br bond lengths of 258 pm and 260 pm; in the [Mo₂Br₆(NO)₄]^2? ion each molybdenum has two covalently bonded nitrosyl groups on cis-position with Mo? N bond lengths of 183 pm. In the [Mo₂Br₆S₂(NO)₂]^2? ion one of the two nitrosyl groups at each metal atom is substituted by a terminal sulfido ligand with a Mo? S bond length of 240 pm. The i.r. spectra are reported.     

Secondary interactions in 4‐bromo‐N,N‐dimethylanilinium bromide

The crystal packing of the title compound, C₈H₁₁BrN⁺·Br^?, involves three types of secondary interaction: a classical N—H?Br^? hydrogen bond, a `weak' but short C—H?Br^? interaction (normalized H?Br distance of 2.66 Å) and a cation–anion Br?Br contact of 3.6331 (4) Å. The hydrogen bonds connect two cations and two anions to form rings of graph set R(14). The Br?Br contacts link these rings to form layers parallel to the bc plane.     

Tetrakis­(diethyl­amino)­phospho­nium bromide hemihydrate

The structure of the title compound, C₁₆H₄₀N₄P⁺·Br^?·0.5H₂O or [P{N(C₂H₅)₂}₄]Br·0.5H₂O, at 130 K has Z′ = 4 and is ionic, with Br not bonded to P. The P atoms are tetrahedral, with P—N distances in the range 1.628 (2)–1.6400 (19) Å. The N atoms are approximately planar. The water mol­ecules form cyclic hydrogen‐bonded [(H₂O)₂Br₂]^2? units about inversion centers, with O?Br distances in the range 3.425 (2)–3.611 (3) Å.     

On the preparation of binuclear S,S bridged molybdenum(V) complexes crystal and molecular structure of [Mo2S4(Et2dtc)2]

MoO₄^2? is reduced by diethyldithiocarbamate (Et₂dtc^?) on prolonged digestion in aqueous medium whereby the complex [Mo₂^VO₂S₂(Et₂dtc)₂] is formed. The central moiety Mo₂O₂S₂²⁺ has a high formation tendency. When [Mo₂^V(S₂)₆]^2? is refluxed with Et₂dtc^? in ethanol, [Mo₂^VS (Et₂dtc)₂] is formed, the X-ray crystal structure of which has been determined (space group P2₁2₁2₁, a = 10.550(2) Å, b = 13.820(5) Å, c = 14.723(12) Å, d_c = 1.90 g · cm^3?, Z = 4). The Mo? Mo distance of the diamagnetic compound is 2.817(2) Å and the average Mo=S_t distance 2.099(4) Å.     

Periphere Anbindung von Quecksilber(II)-iodid an dreikernige Molybdän-Schwefel-Dithiophosphinatocluster: [Mo3S4(R2PS2)4HgI2] (R = Et,Pr)

Peripheral Bonding of Mercury(II) Iodide to Trinuclear Molybdenum-Sulfur-Dithiophosphinato Clusters: [Mo₃S₄(R₂PS₂)₄HgI₂] (R = Et, Pr) Reaction of Mo₃S₄(R₂PS₂)₄ 1 (a : R = Et, b : R = Pr) with HgI₂ in THF yields the diamagnetic title complexes [Mo₃S₄(R₂PS₂)₄HgI₂] 3 . The crystal structure of [ 3a (H₂O)] · 2 CH₂Cl₂ shows the complexes to consist of a triangular array of Mo atoms which are bridged by μ₂? S atoms and capped by a μ₃? S atom. Each of the Mo atoms is chelated by a dithiophosphinato ligand Et₂PS₂^? and in addition two Mo atoms are bridged by a Et₂PS₂^? ligand while the H₂O molecule is bonded weakly to the third Mo atom. Thus, all Mo atoms reveal a distorted octahedral coordination sphere. HgI₂ is ?peripherally”? bonded to the cluster via two S atoms, one of which belongs to a chelating ligand and the other one to the bridging ligand. Space group P1 , lattice constants a = 12.157(2), b = 15.284(3), c = 16.049(3) Å, α = 115.56(1), β = 107.35(1), and γ = 94.62(1)°; Z = 2, d_calc = 2.23 mg/mm³; 4 236 observed reflections, R = 0.068. In organic solvents complexes 3 are strong electrolytes. VT-³¹P NMR data suggest a stepwise dissociation of 3 with formation of [Mo₃S₄(R₂PS₂)₃] ⁺[(R₂PS₂)HgI₂]^? and elimination of the bridging ligand from the cluster.     

Studies on organometallic compounds with hetero multiple bridges : V. Crystal and molecular structure of the parent rhenium complex Re2Br2(CO)6(THF)2 and substituted products of tricarbonylrhenium(I) derived from it

Reactions of the tetrahydrofuran adduct Re₂Br₂(CO)₆(THF)₂ with some phosphorous- and nitrogen-containing donors under mild conditions are reported, which led to the formation of substituted products of tricarbonylrhenium(I). Bromide abstraction from the THF adduct by secondary amines and CS₂ produced the dithiocarbamato derivatives Re(S₂CNR₂)(CO)₃(HNR₂) whose behaviour in solution with CO was also investigated. Mass spectral data for some of the substituted products have been measured. The title compound crystallizes in the space group P2₁/n with cell constants a = 8.661(2), b = 11.251(3), c = 11.424(3) Å and β = 110.36(2)°, U = 1043.67 ų and D_calc = 2.686 g cm^?3, Z = 2. The molecule consists of a planar Re₂Br₂ moiety, as demanded by symmetry. The two THF groups are on opposite sides of this plane and the three CO groups around each rhenium atom are arranged in a fac arrangement. The unique ReBr distances are 2.642(5) and 2.644(4)Å, while the ReO distance is 2.129(31) Å. The ReBrRe and BrReBr angles are 97.3(2) and 82.7(1)°, respectively. The Re?Re nonbonding distance is 3.967(3) Å. The THF ligands consist of a nearly planar C₄ fragment (maximum deviation from planarity 0.06 Å), while the oxygen is 0.348 Å out of that plane, the angle defined by the C₄ plane and the COC fragment of the THF ligand being 24.99°. Final values of the discrepancy indices are R(F) = 0.074 and R_w(F) = 0.095.     

[Rb2(H2O)2][Re3(μ-Cl)3Br7(H2O)2]2 · H2O,ein gemischtes Halogenid-Hydrat mit anionischen Dimeren {[Re3(μ-Cl)3Br7(H2O)2]2 · H2O}2−

[Rb₂(H₂O)₂][Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O, a Mixed Halide-Hydrate with the Anionic Dimer {[Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O}^2? [Rb₂(H₂O)₂][Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O crystallizes as dark redbrown single crystals from an hydrobromic-acid solution of ReCl₃ and RbBr at 0°C. An important feature of the crystal structure (monoclinic, C2/c; a = 1494.61(8); b = 835.71(4); c = 3079.96(19) pm; β = 97.801(4)°; V_m = 573.9(4) cm³mol^?1; R = 0.060; R_w = 0.038) is the connection of two anions [Re₃(μ-Cl)₃Br₇(H₂O)₂]^? via a water molecule to dimers, {[Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O}^2?. These dimeric units are contained in slabs that are stacked in the [001] direction and held together by Rb⁺ cations and crystal water.     

Molecular structure of WO2Br2

Molecular structure of WO₂Br₂ has been studied by electron diffractometry. Structural parameters for the molecule with C_2v symmetry are: r_α(W=O)=1.710(6) Å, r_α(W?Br)=2.398(5) Å, r_α(O?O)=2.815(30) Å, r_α(Br?Br)=4.021(16) Å, r_α(O?Br)=3.347(10) Å. The OWO and BrWBr bond angles are close to tetrahedral:L _αOWO=110.8(2.0)°, L_αBrWBr=113.9(1.0)°. The W=O bond was found to be characteristic in the series of tungsten dioxyhalides.     

Synthesis and structure of the cluster μ3-sulfido-μ-–(diethylphosphorodithioato-S,S'-)-allylthioureocyclo-tris-[ (μ-sulfido)-χ-(diethylphosphorodithioato-S,S')-molybdenum(IV)], Mo3S4(C4H10O2S2P)4(C4H8N2S)

Title compound, M_r =1273.16, was synthesized by a substitution reaction and its crystal is triclinic belonging to space group P1 with cell parameters: a =13.944(2), b =14.143(7), c =14.233(3) Å, α =77.35(3)°, β =69.94(2)°, γ =63.50(3)°, V=2351(1) ų, Z=2, D_c =1.799g cm^?2. Room temperature, graphite-filtered Mo K_α radiation (λ =0.71073Å) was used for data collection. μ =14.988 cm^?1, F(000) =1280, R=0.051 for 7025 observed reflections. The crystal consists of decrete cluster molecules containing a cluster core [Mo₂(μ₃-S)]¹⁰⁺ with three μ-S, one μ-dtp(dtp =[S₂P(OC₂H₅)]^2-), three χ-dtp and one allylthioureo to form a local six-coordinated sphere around each Mo atom. The bonds of cluster skeleton [Mo₃(μ₃-S)(μ-S)₃]⁴⁺, Mo? Mo 2.744～2.766, Mo—(μ₂-S) 2.340～2.342 and Mo—(μ-S)2.272～2.296 Å, are comparable with those found in the related analogues.