Neue Koordinations-Motive bei Cyclothiazeno-Komplexen von Molybdän und Wolfram. Die Kristallstrukturen von [{Mo(N3S2)(Cl)(OtBu)2}{Mo(O)(N3S2)(OtBu)}]2 und [W(N3S2)2(LiCl){N≡W(NPPh3)3}2]

New Coordination Motives at Cyclothiazeno Complexes of Molybdenum and Tungsten. Crystal Structures of [{Mo(N₃S₂)(Cl)(O^tBu)₂}{Mo(O)(N₃S₂)(O^tBu)}]₂ and [W(N₃S₂)₂(LiCl){N≡W(NPPh₃)₃}₂] The metalla cyclothiazeno complexes (Cyclo-1λ⁶-metalla-3,5-dithia-2,4,6-triazino complexes) [{Mo(N₃S₂)(Cl) · (O^tBu)₂}{Mo(O)(N₃S₂)(O^tBu)}]₂ ( 1 ) and [W(N₃S₂)₂(LiCl) · {N≡W(NPPh₃)₃}₂] ( 2 ) are formed from [MoCl₃(N₃S₂)]₂ and LiO^tBu in toluene, and from [WCl₃(N₃S₂)]₂ and LiNPPh₃ in THF, respectively. The complexes form moisture sensitive, black ( 1 ) or brown ( 2 ) crystals, which we characterized by crystal structure analyses. 1 · Toluene: Space group P 1, Z = 1, lattice dimensions at –83 °C: a = 934.2(1), b = 964.4(1), c = 1700.3(1) pm; α = 83.54(1)°, β = 78.35(1)°, γ = 71.56(1)°, R₁ = 0.0339. 2 · 1.625 Toluene · 0.75 THF: Space group P 1, Z = 4, lattice dimensions at –80 °C: a = 1313.8(1), b = 2896.8(2), c = 3384.9(3) pm; α = 82.42(1)°, β = 88.71(1)°, γ = 77.28(1)°, R₁ = 0.0603.     

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF TRIS(DIMETHYLDITHIOCARBAMATE) INDIUM(III), In[S2CN(CH3)2]3

Abstract

The synthesis and structure of the indium dithiocarbamate, In[S₂CN(CH₃)₂]₃·(1/2) 4-mepy (4-mepy=4-methylpyridine), is described. Indium metal was oxidized by tetramethylthiuram disulfide in 4-methylpyridine at 25°C to form a new, homoleptic indium(III) dithiocarbamate in yields exceeding 60%. In[S₂CN(CH₃)₂]₃ exists as a discrete molecule with a distorted-octahedral geometry. The compound crystallizes in the P 1 (No. 2) space group with a=9.282(1)Å, b=10.081(1)Å, c=12.502Å, α=73.91(1)°, β=70.21(1)°, γ=85.84(1)°, Z=2, V(Å)=1057.3(3), R=0.046 and R_w =0.061.     

A pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid

The crystal structures of a pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid, namely (R)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (I), and (S)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (II), both C₅H₁₄N₂²⁺·2C₄H₅O₆⁻·H₂O, each reveal the formation of well‐defined head‐to‐tail‐connected hydrogen tartrate chains; these chains are linked into a two‐dimensional sheet via intermolecular hydrogen bonds involving hydroxy groups and water molecules, resulting in a layer structure. The (R)‐2‐methylpiperazinediium ions lie between the hydrogen tartrate layers in the most stable equatorial conformation in (I), whereas in (II), these ions are in an unstable axial position inside the more interconnected layers and form a larger number of intermolecular hydrogen bonds than are observed in (I).     

Heptane-soluble homogeneous zirconocene catalyst: Synthesis of a single diastereomer,polymerization catalysis,and effect of silica supports

Bis(1-indenyl)-di[1′S, 2′R, 5′S)-methoxy]silane ( 1 ) was converted into a mixture of corresponding ansa-diastereomeric zirconocenes. Further purification afforded a single dia-stereomer, di[(1′S, 2′R, 5′S)-methoxy] silylene-bis[η⁵-1(R, R)-(+)-indenyl] dichlorozirconium ( 2 ), which is optically active and hydrocarbon soluble. Extremely rapid ethylene, propylene, and ethylene-hexene polymerizations were observed both in toluene and n-heptane solutions; for instance, at 50°C, activity for ethylene polymerization reaches ～ 1.5×10¹⁰ (g of PE/((mol of Zr) · [C₂H₄] · h). The “bare” zirconocenium ion generated from 2/TIBA/Ph₃CB(C₆F₅)₄ exhibits unusual polymerization behaviors; the polymerization activity increases monotonically with temperature of polymerization (T_p) up to a conventional polymerization condition (50–70°C), and the ¹³C NMR study shows that the isotactic poly-propylene obtained has fairly high [mmmm] methyl pentad distributions at high T_p (?25°C with [mmmm] ～ 0.93–0.75) and a perfect stereoregularity at low T_p (?0°C with [mmmm] > 0.99). The catalyst precursors 2 and Et(Ind)₂ZrCl₂ ( 3 ) supported on silica by different approaches produced poly(olefins) of different molecular weights and stereoregularities, and a methylaluminokane and Ph₃CB(C₆F₅)₄ free silica-supported zirconocene system was found to be activated by triisobutylaluminum. © 1995 John Wiley & Sons, Inc.     

Synthesis of (+)-1,3:2,5-dianhydroviburnitol ((+)-(1R,2R,3S,5R,6S)-4,7-dioxatricyclo[3.2.1.03,6]octan-2-ol)

Epoxidation of (?)-(1R,2R,4R)-2-endo-cyano-7-oxabicyclo[2.2.1]hept-5-en-2-exo-yl acetate ((?)-5) followed by saponification afforded (+)-(1R,4R,5R,6R)-5,6-exo-epoxy-7-oxabicyclo[2.2.1]heptan-2-one ((+)-7). Reduction of (+)-7 with diisobutylaluminium hydride (DIBAH) gave (+)-1,3:2,5-dianhydroviburnitol ( = (+)-(1R,2R,3S,4R,6S)-4,7-dioxatricyclo[3.2.1.0^3,6]octan-2-ol; (+)-3). Hydride reductions of (±)-7 were less exo-face selective than reductions of bicyclo[2.2.1]heptan-2-one and its derivatives with NaBH₄, AlH₃, and LiAlH₄ probably because of smaller steric hindrance to endo-face hydride attack when C(5) and C(6) of the bicyclo-[2.2.1]heptan-2-one are part of an exo oxirane ring.     

Synthesis and Crystal Structure of Hexakis(N—allylthiourea)tetracopper(I) Tetratrifluoromethanesulfonate, [Cu4{CH2=CHCH2NHC(S)NH2}6](SO3CF3)4

Hexakis(N—allylthiourea)tetracopper(I) Tetratrifluoromethanesulfonate, [Cu₄{CH₂=CHCH₂NHC(S)NH₂}₆](CF₃SO₃)₄ (sp.gr.P2₁/n, a = 13.5463(8), b = 24.129(2), c = 19.128(1)Å, β = 108.053(6)°, Z = 4, R = 0.0440 for 13548 unique reflections) was obtained by reduction of Cu(CF₃SO₃)₂ with excess of N—allylthiocarbamide in benzene medium. Four crystallographical independent Cu atoms possess trigonal environment of three S atoms of CH₂=CHCH₂NHC(S)NH₂ moiety and form Cu₄S₆⁴⁺ adamantane—like fragments. The latteres are connected with CF₃SO₃^— anions via (C)—H···F hydrogen bonds.     

Synthesis and Structures of [Mo12E16(PEt3)10] (E = S,Se)

Dodecanuclcar cluster complexes [Mo₁₂S₁₆(PEt₃)₁₀] 1 and [Mo₁₂Se₁₆(PEt₃)₁₀] 2 have been prepared by the reactions of [Mo₆S₈(PEt₃)₆] with sulfur or [Mo₆Se₈(PEt₃)₆] with Cp₂TiSe₅, respectively, in toluene at refluxing temperature. The structures have been determined at 173 K by X-ray crystallography. The compound 1 ·3CHCl₃ crystallizes in the triclinic space group $ {\rm P}\bar 1 $, with a = 14.859(5) Å, b = 15.868(4) Å, c = 14.200(7) Å, α = 100.58(3)°, β = 117.58(3)°, γ = 79.53(2)°, V = 2899(1) ų, and Z = 1. Full-matrix least-squares refinement using 9016 observed reflections (I_o > 2σ(I_o)) gave R = 0.056, and R_w = 0.045. The data for 2 ·2CHCl₃ are: triclinic, $ {\rm P}\bar 1 $, a = 15.737(4) Å, b = 18.763(9) Å, c = 13.062(4) Å, α = 102.45(3)°, β = 128.54(2)°, γ = 69.49(3)°, V = 2825 ų, Z = 1, R = 0.096, and R_w = 0.120 for 5922 reflections (I_o > 2σ(I_o)). The cluster complexes 1 and 2 have two octahedral molybdenum cluster units linked by the rhomboidal intercluster Mo₂(μ₄-E)₂ bonding. The intercluster Mo—Mo distances in 1 are 3.419 Å and 2 3.551 Å. The cyclic voltammetry of 1 and 2 shows two oxidation and two reduction steps separated as large as 380–490 mV. The UV-Vis spectra of the dodecanuclear cluster complexes 1 and 2 have an extra weak band at around 744 nm which is absent in the starting octahedral cluster complexes.     

A pair of diastereomeric 1:1 salts of (S)‐ and (R)‐2‐methylpiperazine with (2S,3S)‐tartaric acid

The structures of diastereomeric pairs consisting of (S)‐ and (R)‐2‐methylpiperazine with (2S,3S)‐tartaric acid are both 1:1 salts, namely (S)‐2‐methylpiperazinium (2S,3S)‐tartrate dihydrate, C₅H₁₄N₂²⁺·C₄H₄O₆²⁻·2H₂O, (I), and (R)‐2‐methylpiperazinium (2S,3S)‐tartrate dihydrate, C₅H₁₄N₂²⁺·C₄H₄O₆²⁻·2H₂O, (II), which reveal the formation of well defined ammonium carboxylate salts linked via strong intermolecular hydrogen bonds. Unlike the situation in the more soluble salt (II), the alternating columns of tartrate and ammonium ions of the less soluble salt (I) are packed neatly in a grid around the a axis, which incorporates water molecules at regular intervals. The increased efficiency of packing for (I) is evident in its lower `packing coefficient', and the hydrogen‐bond contribution is stronger in the more soluble salt (II).     

1-(2′-Deoxy-β-D-xylofuranosyl)cytosine: Base pairing of oligonucleotides with a configurationally altered sugar-phosphate backbone

Solid-phase synthesis of the oligo(2′-deoxynucleotides) 19 and 20 containing 2′-deoxy-β-D -xylocytidine ( 4 ) is described. For this purpose, 1-(2-deoxy-β-D -threo-pentofuranosyl)cytosine ( = 1-(2-deoxy-β-D -xylofuranosyl)-cytosine; 4 ) was protected at its 4-NH₂ group with a benzoyl (→ 5 ) or an isobutyryl (→ 8 ) residue, and a dimethoxytrityl group was introduced at 5′-OH (→ 7, 10 ; Scheme 2). Compounds 7 and 10 were converted into the 3′-phosphonates 11a,b . While 19 could be hybridized with 21 and 22 under formation of duplexes with a two-nucleotide overhang on both termini ( 19 · 21 : T_m 29°; 19 · 22 : T_m 22°), the decamer 20 bearing four xC_d residues could no longer be hybridized with one of the opposite strands. Moreover, the oligonucleotides d[(xC)₈? C] ( 13 ), d[(xC)₄? C] ( 14 ), d[C? (xC)₄? C] ( 15 ), and d[C? (xC)₃? C] ( 16 ) were synthesized. While 13 exhibits an almost inverted CD spectrum compared to d(C₉) ( 17 ), the other oligonucleotides show CD spectra typical for regular right-handed single helices. At pH 5, d[(xC)₈? C] forms a stable hemi-protonated duplex which exhibits a T_m of 60° (d[(CH⁺)₉] · d(C₉): T_m 36°). The thermodynamic parameters of duplex formation of ( 13H ⁺ · 13 ) and ( 17H ⁺ · 17 ) were calculated from their melting profiles and were found to be identical in ΔH but differ in ΔS ( 13H ⁺ · 13 : ΔS = ?287 cal/K mol; 17H ⁺ · 17 : ΔS = ?172 cal/K mol).     

Crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo [8.8.8]hexacosane (2S,3S)-tartrate

Crystal structure of (2S,3S)-tartrate of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo-[8.8.8]hexacosane, [H₂(Crypt-222)]²⁺·(C₄H₄O₆)^2? (I) has been studied by single crystal X-ray diffraction. Triclinic structure of I (space group P1, a = 8.424 Å, b = 13.011 Å, c = 13.806 Å; α = 116.37°, β = 106.45°, γ = 91.81°; Z = 2) was solved by the direct method and refined in the full-matrix anisotropic approximation to R = 0.140 for 5850 measured independent reflections (automated diffractometer CAD-4, λMoK _α). In the structure of I, two independent dications of 2.2.2-cryptand (nitrogen atoms are protonated) are linked to the approximate inversion symmetry and have a rare conformation of exo-exo type, when two atoms sitting on N atoms are protruded out of their cavity. The centroids of two crystallographically unique (2S,3S)-tartrate dianions are bound with the same approximate inversion center. An extended system of hydrogen bonds is developed in the crystal of I.     

Earth Alkaline Tetrathiosquarates: Syntheses and Crystal Structures of MgC4S4 · 6 H2O and CaC4S4 · 4 H2O

Concentrated aqueous solutions of magnesium chloride and calcium nitrate, respectively, allow on addition of the potassium salt of tetrathiosquarate, K₂C₄S₄ · H₂O, the isolation of the earth alkaline salts MgC₄S₄ · 6 H₂O ( 1 ) and CaC₄S₄ · 4 H₂O ( 2 ) as orange and red crystals. The crystal structure determinations ( 1 : monoclinic, C2/c, a = 17.2280(7), b = 5.9185(2), c = 13.1480(4) Å, β = 104.730(3)°, Z = 4; 2 : monoclinic, P2₁/m, a = 7.8515(3), b = 12.7705(5), c = 10.6010(4) Å, β = 93.228(2)°, Z = 4) show the presence of C₄S₄^2? ions with almost undistorted D_4h symmetry having average C–C and C–S bond lengths of 1.451Å and 1.659Å for 1 and 1.451Å and 1.655Å for 2 . The structure of 1 contains discrete, octahedral [Mg(H₂O)₆]²⁺ complexes. Several O–H····O and O–H····S bridges with H····O and H····S distances of less than 2.50Å connect cations and anions. The structure of 2 is built of concatenated, edge‐sharing Ca(H₂O)₆S₂ polyhedra. The Ca²⁺ ions have the coordination number eight, C₄S₄^2? act as a chelating ligands towards Ca²⁺ with Ca–S distances of 3.14Å. The infrared and Raman spectra show bands typical for the molecular building units of the two compounds.     

Effects on Coordination of Thioether Sites. 4. Structural Analysis of η3-Tripodal Ligand Manganese(I) Complexes

Crystal structures of a series of manganese(I) complexes containing tripodal ligands were determined. For [η³-{CH₃C(CH₂PPh₂)₂(CH₂SPh)-P,P′,S}Mn(CO)₃]PF₆ ( 1 ): a = 10.856(3) Å, b = 19.698(3) Å, c = 17.596(5) Å, β = 96.17(2)°, monoclinic, Z = 4, P2₁/c, R(F_o) = 0.068, R_w(F_o) = 0.055 for 3617 reflections with I_o > 2σ(I_o). For [η³-{CH₃C(CH₂PPh₂)(CH₂SPh)₂-P,P′,S}Mn(CO)₃]PF₆ ( 2 ): a = 9.890(2) Å, b = 20.403(4) Å, c = 10.269(3) Å, β = 117.44(2)°, monoclinic, Z = 2, P2_l, R(F_o) = 0.050, R_w(F_o) = 0.037 for 1760 reflections with I_o > 2σ(I_o). For [η³-{CH₃C(CH₂PPh₂)₂(CH₂S)-P,P′,S}Mn(CO)₃] ( 4 ): a = 8.191(7) Å, b = 10.495(3) Å, c = 19.858(6) Å, α = 99.61(2)°, β = 96.17(2)°, γ = 92.70(4)°, triclinic, Z = 2, P-I, R(F_o) = 0.048, R_w(F_o) = 0.039 for 2973 reflections with I_o > 2σ(I_o). There is no significant difference in the bond lengths of Mn-S bonds among three species in their crystal structures [2.325(2) Å in 1; 2.358(4) in 2; 2.380(2) in 4], but the better donating ability of thiolate in complex 4 appears on the lower frequencies of its carbonyl stretching absorptions.     

Two (+)‐α,4‐dimethyl‐2‐oxocyclo­hexaneacetic acids: hydrogen bonding in a terpenoid γ‐keto acid and in a diastereomeric lactol

The (+)‐(αS,1S,4R)‐diastereomer of the title structure, C₁₀H₁₆O₃, aggregates in the solid as non‐symmetric dimers with disorder in both carboxyl groups [O·O = 2.710 (5) and 2.638 (5) Å]. The two mol­ecules constituting the asymmetric unit pair around a pseudo‐twofold rotational axis and differ only slightly in their distances and angles, but one methyl group displays rotational disorder absent in the other mol­ecule. Five inter­molecular C—H·O close contacts exist, involving both ketone groups. The (+)‐(αR,1R,4R)‐diastereomer exists in the crystal in its closed‐ring lactol form, (3R,3aR,6R,7aR)‐2,3,3a,4,5,6,7,7a‐octa­hydro‐7a‐hydroxy‐3,6‐dimethyl­benzo[b]furan‐2‐one, C₁₀H₁₆O₃, and aggregates as hydrogen‐bonded catemers that extend from the hydroxyl group of one mol­ecule to the carbonyl group of a neighbor screw‐related along b [O·O = 2.830 (3) Å and O—H·O = 169°]. One close inter­molecular C—H·O contact exists involving the carbonyl group.     

Einkristalle von A?Nd2S3, U?Ho2S3, D?Er2S3 und E?Lu2S3 durch Oxidation reduzierter Chloride der Lanthanide mit Schwefel

Single Crystals of A? Nd₂S₃, U? Ho₂S₃, D? Er₂S₃, and E? Lu₂S₃ through the Oxidation of Reduced Lanthanide Chlorides with Sulfur The oxidation of reduced chlorides (MCl₂) or chloridehydrides (MClH_x) of the lanthanides with sulfur (850°C, 7 d, tantalum ampoule) usually results in the formation of their sesquisulfides (M₂S₃) as the main product. In the presence of appropriate fluxes (e. g., NaCl), they often are obtained as single crystals, and the flux appears to decide which modification is favourized. Single crystals of Nd₂S₃ , (from NdCl₂ + NaCl + S, 2 : 2 : 1, A-type: orthorhombic, Pnma (no. 62), Z = 4; a = 743.97(5), b = 402.78(3), c = 1551.96(9) pm, V_m = 70.015(8) cm³/mol, R , = 0.026, R_w = 0.023), Ho₂S₃ , (from Na_0.25HoClH_0.75 + S, 8 : 9, U type: orthorhombic, Pnma (no. 62), Z = 4, a = 1057.24(7), b = 384.48(4), c = 1041.15(7) pm, V_m = 63.716(9) cm³/mol, R , = 0.023, R_w = 0.020), Er₂S₃ , (from ErClH_0.67 + NaCl + S, 2 : 2 : 1, D type: monoclinic, P2₁/m (no. 11), Z = 6, a = 1744.18(9), b = 398.22(3), c = 1010.13(6) pm, β = 98.688(4)°, V_m = 69.610(7) cm³/mol, R = 0.031, R_w = 0.029) and Lu₂S₃ , (from LuClH_0.67 + NaCl + S, 2 : 2 : 1, E type: trigonal, R3 c (no. 167), Z = 6, a = 672.86(2), c = 1816.84(9) pm, c/a = 2.70, V_m = 71.497(6) cm³/mol, R = 0.023, R_w = 0.020) as well as more systematic general investigations (syntheses of the lanthanide sesquisulfides from the elements in the presence of NaCl as a flux in sealed tantalum containers at 850°C) are the main topic of the work presented here.     

[Cu3(S4)3]−, ein neues kondensiertes anorganisches Ringsystem Strukturvergleich mit anderen Polysulfido-Clustern des Kupfers

[Cu₃(S₄)₃]^3?, a New Condensed Inorganic Ring System. Comparison with the Structures of Other Polysulfido Clusters of Copper By reaction of Cu(CH₃COO)₂ · H₂O with a polysulfide solution [(C₆H₅)₄P]₂(NH₄)-[Cu₃(S₄)₃] · 2CH₃OH ( 1a ) could be obtained in a pure form. The anion [Cu₃(S₄)₃]^3? ( 1 ) consists of a central Cu₃S₃ ring and three CuS₄ rings. An X-ray structure analysis yields the following results for 1a : Space group P2₁/c, a = 2317.4(7), b = 1458.4(4), C = 1843. 1(5) pm, β = 108.68(2)°, V = 5901.0 10⁶ pm³, Z = 4; R = 0.101 for 3817 independent reflections (Fo > 3.92° (Fo)). 1a was also characterized by its Raman spectrum.     

Structural diversity in imidazolidinone organocatalysts: a synchrotron and computational study

(S)‐1‐(Methylaminocarbonyl)‐3‐phenylpropanaminium chloride (S2·HCl), C₁₀H₁₅N₂O⁺·Cl⁻, crystallizes in the orthorhombic space group P2₁2₁2₁ with a single formula unit per asymmetric unit. (5R/S)‐5‐Benzyl‐2,2,3‐trimethyl‐4‐oxoimidazolidin‐1‐ium chloride (R3 and S3), C₁₃H₁₉N₂O⁺·Cl⁻, crystallize in the same space group as S2·HCl but contain three symmetry‐independent formula units. (R/S)‐5‐Benzyl‐2,2,3‐trimethyl‐4‐oxoimidazolidin‐1‐ium chloride monohydrate (R4 and S4), C₁₃H₁₉N₂O⁺·Cl⁻·H₂O, crystallize in the space group P2₁ with a single formula unit per asymmetric unit. Calculations at the B3LYP/6–31G(d,p) and B3LYP/6–311G(d,p) levels of the conformational energies of the cation in R3, S3, R4 and S4 indicate that the ideal gas‐phase global energy minimum conformation is not observed in the solid state. Rather, the effects of hydrogen‐bonding and van der Waals interactions in the crystal structure cause the molecules to adopt higher‐energy conformations, which correspond to local minima in the molecular potential energy surface.     

Kristallstruktur und Schwingungsspektrum von (H2NPPh3)2[SnCl6]·2CH3CN

Crystal Structure and Vibrational Spectrum of (H₂NPPh₃)₂[SnCl₆]·2CH₃CN Single crystals of (H₂NPPh₃)₂[SnCl₆]·2CH₃CN ( 1 ) were obtained by oxidative addition of tin(II) chloride with N‐chloro‐triphenylphosphanimine in acetonitrile in the presence of water. 1 is characterized by IR and Raman spectroscopy as well as by a single crystal structure determination: Space group , Z = 2, lattice dimensions at 193 K: a = 1029.6(1), b = 1441.0(2), c = 1446.1(2) pm, α = 90.91(1)°, β = 92.21(1)°, γ = 92.98(1)°, R₁ = 0.0332. 1 forms an ionic structure with two different site positions of the [SnCl₆]^2? ions. One of them is surrounded by four N‐hydrogen atoms of four (H₂NPPh₃)⁺ ions, four CH₃CN molecules form N–H···N≡C–CH₃ contacts with the other four N‐hydrogen atoms of the cations. Thus, 1 can be written as [(H₂NPPh₃)₄(CH₃CN)₄(SnCl₆)]²⁺[SnCl₆]^2?.     

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)}.     

The reaction of 2′ 2′ 3′ 3′-tetrafluoropropyl-5-iodo-3-oxaoctafluoropentane sulfonate with dimethylsulfoxide and determination of the crystal structure of one of the products

The title reaction gave three known compounds (2, 3 and 4) and two new compounds, CH₃SCH₂(CF₂)₂H (5) and I(CF₂)₂O(CF₂)₂SO₃⁻S+(CH₃)₃ (6). The structure of 6 was confirmed by X-ray diffraction analysis. The crystals of 6 belong to monoclinic space group P2₁/C with a = 9.399, b = 15.651, c=10.934Å, β = 94.80° and z = 4. The structure was solved by heavy-atom method and refined by block-diagonal matrix least-squares procedure to a final R of 0.054 for 1999 independent observed reflexions. The S C bonds around the sulphur atom in trimethylsulphonium are pyramidal with the bond lengths of 1.814 Å, 1.800Å and 1.818 Å and the bond angles C-S-C of 101.06°, 101.52° and 102.53°. The distances of the sulphur atom in trimethylsulphonium to three oxygen atoms in the sulphonate radical are 3.79 Å, 3.64 Å and 3.34 Å respectively. These distances are out of the range of the normal S-O bond length. The structure consists of trimethylsulphonium cations and 5-iodo-3-oxaoctafluoropentane-sulphonate anions.     

New compounds in the cesium sulfobromide rhenium octahedral cluster chemistry: syntheses and crystal structures of Cs4Re6S8Br6 and Cs2Re6S8Br4

The exploration of the CsReSBr system, in order to identify new phases based on octahedral cluster anions, has produced single crystals of Cs₄Re₆S₈Br₆ (1) (trigonal, space group P-6c2, a=9.7825 (3) Å, c=18.7843 (5) Å, V=1556.77 (1) ų, Z=2, density=5.09 g cm⁻³, μ=36.07 mm⁻¹) and Cs₂Re₆S₈Br₄ (2) (monoclinic, space group P2₁/n, a=6.3664 (1) Å, b=18.4483 (4) Å, c=9.3094 (2) Å, β=104.2618 (8)°, V=1059.69 (4) ų, Z=2, density=6.14 g cm⁻³, μ=45.83 mm⁻¹). These two compounds have been obtained by high-temperature solid state route. Their structures have been solved and refined from single crystal X-ray diffraction data. The structure of Cs₄Re₆S₈Br₆ presents isolated anionic cluster units inscribed in a (Cs⁺)₁₂ cuboctahedron and the one of Cs₂Re₆S₈Br₄ exhibits ReS^i-a,a-iRe inter-unit bridges. The framework of the latter presents then a strongly 1-D character.