Crystal Structure of Loliolide (5, 6,7a-Tetrahydro-6-hydroxy-4, 4, 7a-trimethyl-2 (4H)-benzofuranones)

1INTRODUCTIONThetitlecompound,C,,H,,O,(mp:146～148'C),forthefirsttime,wasiso-latedfromClinopodiumpolycephalum(Vant-)byC.Y.WuetHsuancalled"DuanXueliu"inChinesethatisusedinfolkmedicineforthetreatmentofhaemorrhagiadisease[1i.Itsstructurehasalreadybeendeterminedt2ibymeansofUV,lR,NMRandchemicalsynthesis.Sinceloliolideappearedtohaveantitumoractivity"'andim-munosuppressiveactivity'#'inrecentyears,weaffirmedthestructurebyX-raydiffractionanalysis.2EXPERIMENTALApaleyellowtransparentcry…     

Crystal Growth and Crystal Structures of Gold(V) Compounds: Cu(AuF6)2, Ag(AuF6)2, and O2(CuF)3(AuF6)4 ⋅ HF

Crystal growth from anhydrous hydrogen fluoride solutions of M²⁺ (M=Cu, Ag) and [AuF₆]⁻ gave M(AuF₆)₂ salts (M=Cu, Ag). Similar attempts to prepare single crystals of the corresponding nickel, zinc and magnesium salts failed. The crystal structure of Cu(AuF₆)₂ consists of layers of Cu²⁺ cations connected by [AuF₆]⁻ anions, thus forming slabs. Only van der Waals interactions exist between adjacent slabs. The crystal structure of Ag(AuF₆)₂ consists of a three-dimensional framework in which Ag⁺ cations are linked by [AuF₆]⁻ anions. Both structures are members of the M^II(X^VF₆)₂ family, in which seven different structure types have been observed to date. In the crystal structure of O₂(CuF)₃(AuF₆)₄ ⋅ HF, the bridging AuF₆ units connect [−Cu−F−Cu−F−]_∞ chains to form stacks between which O₂⁺ cations and HF molecules are located.     

Syntheses, 95Mo NMR Spectroscopy and Structures of Distorted Cubic Mo4(��3-O)4(��2-O2P(CH2C6H5)2)4O4 and the Open Mixed-Valent Cluster, Mo4(��3-O)2(��2-O2P(CH2C6H5)2)6O6

The reaction of MoO₂(acac)₂ and dibenzylphosphinic acid in ethanol leads to a red distorted cubic tetrameric cluster, Mo₄(??³-O)₄(??²-O₂P(CH₂C₆H₅)₂)₄O₄, and a pink open mixed-valent cluster, Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆, when the reduction is carried out at 120 and 75 °C, respectively. ⁹⁵Mo NMR spectroscopy revealed a singlet for Mo₄(??³-O)₄(??²-O₂P(CH₂C₆H₅)₂)₄O₄ (1) at 584.9 ppm (????_1/2 = 4500 Hz) and two resonances for Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆ (2) at 238.8 ppm (????_1/2 = 1250 Hz) and 6.4 ppm (????_1/2 = 5999 Hz), which were assigned to the Mo(V) and Mo(VI) sites, respectively. DFT geometries and ⁹⁵Mo DFT-GIAO chemical shifts for Mo₄(??³-O)₄(??²-O₂P(CH₃)₂)₄O₄ (3) and Mo₄(??³-O)₂(??²-O₂P(CH₃)₂)₆O₆ (4) are consistent with X-ray crystallography and ⁹⁵Mo NMR of 1 and 2. The open complex, Mo₄(??³-O)₂(??²-O₂P(CH₂C₆H₅)₂)₆O₆·2(CH₂Cl₂), exhibits a central Mo(V)?CMo(V) single bond at 2.6217(5) Å with each Mo(V) atom bonded to one oxo (trans-disposed) terminal ligand.     

The crystal structure of bis(N-pentafluorophenyl)tetraphenyl-cyclodisilazane-tetrabenzene, (Ph2SiNC6F5)2 · 4C6H6

The disilazane (Ph₂SiNC₆F₅)₂ crystallises from benzene solution with four molecules of solvent in the orthorhombic space group Pnna with a 18.182(6), b 21.480(8) and c 13.631(5) Å, Z = 4. The structure was solved by direct methods and refined by least-squares to R 0.069 for 937 observed reflections. The Si₂N₂ ring is planar with NSiN and SiNSi angles of 85.2 and 95.5° respectively; the mean SiN distance is 1.755 Å. The C₆F₅ groups are twisted by ca. 16° from the Si₂N₂ plane and the benzene molecules are arranged face-on above and below each of the C₆F₅ groups. There are, in addition, short intermolecular contacts between four fluorines of each C₆F₅ group and hydrogen atoms from both solvate benzene and the phenyl groups of a symmetry related silazane. Attempts to refine the related (Me₂SiNC₆F₅)₂ structure were not successful, probably due to disorder.     

Synthesis and structure of the organoantimony peroxide solvates [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·1.5C4H8O2 and [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·6C4H8O2

The organoantimony peroxide (Ar₂SbO)₄(O₂)₂ (Ar = C₆H₃OMe-2, Br-5) was synthesized by the oxidation of Ar3Sb with hydrogen peroxide in the presence or acetoxime or acetophenone oxime in dioxane. The product crystallizes with various content of the solvent molecules in the crystal unit cell [1.5 (I) and 6 (II), respectively]. An X-ray diffraction analysis of the solvates was performed. Four antimony atoms in the peroxide are in the octahedral coordination, and are linked through bridging oxygen atoms and two peroxide groups. The distances Sb-C, Sb-O_bridge, Sb-O_peroxide, O-O and Sb...Sb are 2.117–2.122, 1.960–1.972, 2.193–2.235, 1.461, 1.465 and 3.223–3.237 Å in I, and 2.112, 2.119, 1.957, 1,966, 2.204, 2,246, 1,467, and 3.2439 Å in II.     

Crystal structure of Μ2, η2, Σ2-nitrato-η2, Σ2-nitrato-bis(1-ethyltetrazole-N4)copper(II) Cu(C3H6N4)2(NO3)2 = [Cu(C3H6N4)2(NO3)(NO3)2/2]∞

The complex compound of copper(II) nitrate with 1ethyltetrazole (ettz), Cu( C₃H₆N₄)₂(NO₃)(NO₃)_2/2] is studied by Xray diffraction analysis (“Syntex P2₁” automatic diffractometer, CuK_a radiation, graphite monochromator, 6/26 scan mode with V_min = 3.91 deg/min, the total number of data collected 3544 l_hkb including 3141 nonextinct l_hkl > 0, a correction for absorption (Μ = 25.08 cm^-1) applied by integrating over the crystal faces). The parameters of the orthorhombic unit cell (space group Pccn) are a = 15.436(3), b = 20.198(5), c = 19.587(3) Å, V_cell = 6107(2) Å^{3, Z} = 16, d_calc = 1.670 g/cm³. The two crystallographically independent copper atoms have a distorted octahedral environment (coordination node is CuN₂O₄), coordination number (CN) is 6 = 4 + t2. In the equatorial plane, two nitrogen atoms of ettz and two oxygen atoms of NO ₃ ^? groups are trans to each other; Cu-N = 1.983(8), C-O_{NO 3} ^? = 1.978(7) Å (average). The nitrato groups fulfill chelate and bridging functions, complementing the coordination polyhedra of the copper atoms to distorted octahedra, where Cu-O_{NO 3} ^? = 2.517(7) Å (average). The compound has a chain structure; the chains stretching along [001] are packed pairwise according to the hexagonal law.     

Crystal growth, structural, thermal, and dielectric characterization of Tutton salt (NH4)2Fe(SO4)2·6H2O crystals

A good quality single crystal of Tutton salt, (NH₄)₂Fe(SO₄)₂·6H₂O, with dimensions 6 × 7 × 3 mm³ was successfully grown by the slow evaporation growth technique at ambient temperature. The grown crystal was subjected to single crystal X-ray diffraction study which confirms that the grown crystal is monoclinic in nature with the space group P2₁/c. Optical absorption spectrum reveals that the grown crystal has good optical transparency in the entire visible region and its energy band gap was determined. The thermal behavior of the grown crystal was investigated by thermogravimetric and differential thermal analysis. The dielectric measurements were carried out to determine the dielectric behavior of the crystal.     

New 1D and 2D metal oxygen connectivities in Cu(II) succinato and glutarato coordination polymers: [Cu3(H2O)2(OH)2(C4H4O4)2] · 4H2O, [Cu4(H2O)2(OH)4(C4H4O4)2] · 5H2O and [Cu5(OH)6(C5H6O4)2] · 4H2O

Two Cu(II) hydroxo succinates [Cu₃(H₂O)₂(OH)₂(C₄H₄O₄)₂]?·?4H₂O (1) and [Cu₄(H₂O)₂(OH)₄(C₄H₄O₄)₂]?·?5H₂O (2) and one Cu(II) hydroxo glutarate [Cu₅(OH)₆(C₅H₆O₄)₂]?·?4H₂O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO₆} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO₆} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H₂O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO₆} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H₂O molecules. The {CuO₆} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H₂O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses.     

Synthesis,Structure and Characterization of a New Complex: [Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O

A novel complex,[Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O,was synthesized and hexagonal single crystals with centimeter-scale sizes were obtained by the method of solvent evaporation.It was characterized by elemental analysis,infrared spectrum,thermogravimetric analysis and X-ray single-crystal diffraction.The complex belongs to triclinic crystal system,space group P■ with a=9.3390(8),b=13.3520(13),c=16.3207(13)?,α=100.7160(3)°,β=90.1020(10)°,γ=109.9490(5)°,V=1874.9(3)?~3,Z=2,D_c=1.542 g/cm~3,M_r=870.64,μ=0.876 mm~(-1),T=293(2) K,F(000)=916 and S=0.990.The crystal structure determination displayed a distorted octahedral geometry around the manganese atom,which is bound to two nitrogen atoms from hexamethylenetetramine,acting as monodentate ligands,and to four aqua ligands.Variable-temperature magnetic measurements of the complex indicate the presence of weak antiferromagnetic interaction between manganese centers.     

SYNTHESIS,STRUCTURE AND REACTIVITY OF BIS(N-ARYL-IMINOPHOSPHORANYL)METHANES. X-RAY CRYSTAL STRUCTURES OF (4-CH3-C6H4-N˭PPh2)2CH2 AND (4-NO2-C6H4-N˭PPh2)2CH2

Abstract

The synthesis of novel bis(N-aryl-imino-phosphoranyl)methanes of the type CH₂(PR₂?N-Ar)₂ has been accomplished by reaction of methylene-bisphosphines with arylazides. These compounds have been fully characterized by ¹H, ³¹P and ¹³C NMR, IR spectroscopy, Field Desorption Mass Spectroscopy (? FDMS) and elemental analysis. Variable temperature NMR experiments and single crystal X-ray structure determinations of CH₂(PPh₂?N-C₆H₄-CH₃-4)₂ (la) and CH₂(PMe₂?N-C₆H₄-NO₂-4)₂ (1f) reveal that bis(N-aryl-imino-phosphorany1)methane occurs as tautomer 1. Crystals of la are orthorhombic, space group Pcab, with a = 26.602(2), b = 20.521(1), c = 11.8859(7) Å and V = 6488.5(7) ų (2 = 8, R = 0.045 and R_w = 0.066). The crystals of lf are monoclinic, space group C/2c, with a = 20.153(4), b = 5.952(1), c = 16.930(5) Å, β = 106.24(3)° and V = 1949.6(6) ų (Z = 4, molecular symmetry C₂, R_w = 0.051 and R, = 0.079). Both molecules consist of 2 iminophosphoranyl units bridged by a methylene group. The P?N bond distances of 1.568(2) and 1.566(2) Å for la and 1.580(4) Å for lf represent normal values for iminophosphoranyl compounds. The N-C bond lengths of 1.386(2) and 1.390(2) A (la) or 1.372(5) A for If indicate that some electron delocalisation over the N-aryl moiety takes place. In la the electron delocalisation takes place separately in each iminophosphoranyl entity, while in lf electron delocalisation occurs only in the N-aryl-NO₂ moiety.

Compound la is easily deprotonated using lithium-diisopropylamide or NaH and shows typical iminophosphoranyl chemistry, since with CO₂ an aza-Wittig reaction has been found and with HX (X?CI, Br) protonation of both imide nitrogen atoms has been observed.     

SINGLE Mo_(n)Fe_(4-n)S_(4) (n=0, 1, 2) CUBANE-LIKE CLUSTERS: PREPARATION FROM COMBI-NATION OF DINUCLEAR COMPLEXES AND THE STRUCTUREOF [Mo_(2)Fe_(2)S_(4)(C_(4)H_(8)dtc)_(6)]·3.5C_(2)H_(2)Cl_(4)

Three types of unit combinations, FeS2Fe + FeS2Fe, FeS2Fe + MoS2Fe and MoS2Mo + MoS2Mo, lead to Fe4S4, MoFe3S4 and Mo2Fe2S4 cubane-like clusters, respectively. A new doubly bridged single cubane cluster [Mo2Fe2S4(C4H8dtc)6]·3.5C2H2Cl4 has been obtained and its structure is discussed.     

Cyclohexylamine) 2 M(CN) 4 ⋅2C 6 H 6 (M = Cd or Hg)

Two new title compounds have been prepared in powder form. Their spectral data are found to be consistent with the structure foundin Hofmann-T_d-type clathrates.     

23-Electron Re6 metal clusters: syntheses and crystal structures of (Ph4P)3[Re6S8(CN)6], (Ph4P)2(H)[Re6Se8(CN)6]·8H2O,and (Et4N)2(H)[Re6Te8(CN)6]·2H2O

The cluster anions [Re₆X₈(CN)₆]^34– (X = S, Se, or Te) containing 23 cluster valence electrons in the Re₆ octahedron were synthesized and isolated as salts with organic cations. The crystal structures of the (Ph₄P)₃[Re₆S₈(CN)₆], (Ph₄P)₂(H)[Re₆Se₈(CN)₆]·8H₂O, and (Et₄N)₂(H)[Re₆Te₈(CN)₆]·2H₂O clusters were solved by X-ray diffraction analysis. Removal of one electron has virtually no effect on the geometry and interatomic distances in the cluster anion but leads to a substantial change in the electronic spectrum and to an increase in stretching vibration frequencies _CN compared to those of the [Re₆X₈(CN)₆]^4– anions.     

Hydrothermal Synthesis, Crystal Structure and Electrochemical Properties of the Copper(Ⅱ) Complex [Cu4O4(phen)4(ClC6H4COO)2(H2O)2]·(H2O)3

The title complex of copper(Ⅱ) with m-chlorobenzoic acid, 1,10-phenanthroline (phen) and copper perchlorate has been synthesized and characterized in the solvent mixture of water and methanol. Crystal data for this complex: triclinic, space group P, a = 1.06853(12), b = 1.30740(16), c = 1.49546(17) nm, α = 101.791(2), β = 103.413(2), γ = 105.815(2)o, V = 1.8736(4) nm3, Mr = 904.67, Dc = 1.604 g/cm3, Z = 2, F(000) = 924, μ = 1.34 mm-1, GOOF = 1.049, the final R = 0.0324 and wR = 0.0797. The structure analysis shows that a chair-like structure [Cu4O4] is defined by three quadrilaterals shaped by four copper and four oxygen atoms, and every copper ion is coordinated by three oxygen atoms from three water molecules and two nitrogen atoms from one 1,10-phenanthroline molecule, giving a distorted square-pyramidal coordination geometry. The CV analysis results indicate that the electron transfer in the electrode reaction is quasi-reversible.     

An infrared and raman spectroscopic study of pyrazinecadmium (II) tetracyanometalate (II) Benzene (1/1) clathrates: Cd(C4H4N2)Cd(CN)4⁗C6H6 and Cd(C4H4N2)Hg(CN)4⁗C6H6

Two new benzene clathrates of the form Cd(Pyrazine)M(CN)₄C₆H₆, where M = Cd or Hg, have been prepared and their infrared and Raman spectra are reported.     

Reversibility of light-induced excited spin state trapping in the Fe(ptz)6(BF4)2, and the Zn1−xFex(ptz)6(BF4)2 spin-crossover systems

Fe(ptz)₆(BF₄)₂ (ptz = 1-propyltetrazole) is an iron(II) spin-crossover system which shows light-induced excited spin state trapping. In this paper we show that (a) the same phenomenon can also be observed in Zn_1−xFe_x(ptz)₆(BF₄)₂ (x ≈ 0.1) and is therefore basically a single-ion property, and (b) that the phenomenon is reversible. The efficiency of the light-induced spin crossover is of the order of 0.5% in the forward direction and 0.1% in the reverse direction.     

CRYSTAL STRUCTURE AND LUMINESCENCE OF (4, 4′ -DIMETHYL-2, 2′ -BIPYRIDINE)-TRIS(BENZOATE)EUROPIUM(III)

Abstract

A mixed ligand europium complex, [Eu(BA)₃dmbpy]₂, has been prepared, where BA = benzoate and dmbpy = 4, 4′-dimethyl-2, 2′-bipyridine. The complex crystallizes in the tri-clinic system, space group P ^? ₁. Its structure has been determined using X-ray diffraction methods. The two europium ions in the molecule are held together by four carboxylate groups of benzoic acid and each europium ion is further bonded to one bidentate carboxylate group and one 4, 4′-dimethyl-2, 2′-bipyridine molecule. Excitation and luminescence spectra observed at 77 K show that the europium site in the crystal has low symmetry and changes of the chemical surroundings of the europium ion in the molecule depend mainly on the flexibility of 4, 4′-dime-thyl-2, 2′-bibyridine.     

Synthesis, molecular structures, and properties of heterometallic cobalt tetramethylcyclobutadiene complexes (C4Me4)Co(CO)2TePh, (C4Me4)Co(CO)2TePh[W(CO)5], and Me4C4Co(μ3-S)2Cr2Cp2(μ-SC4H9)

The reaction of Cb*Co(CO)₂I (1) (Cb* is tetramethylcyclobutadiene) with sodium phenyltelluride afforded the mononuclesar complex Cb*Co(CO)₂TePh (2). The reaction of the latter with W(CO)₅(THF) produced the Cb*Co(CO)₂TePh[W(CO)₅] compound (4). The reaction of 1 with the Cp₂Cr₂(SCMe₃)₂S complex gave the heterometallic cluster Cb*Co(μ₃-S)₂Cr₂Cp2 (μ-SCMe₃) (5). Complexes 2, 4, and 5 are diamagnetic. Their structures were determined by X-ray diffraction. Complex 2 contains the Co-Te bond (2.585(1) Å); complex 4, the Co-Te (2.558(8) Å) and W-Te (2.8467(6) Å) bonds. Complex 5 has the stable triangular sulfide-and tert-butylmercaptide-bridged core Cr₂Co (Cr-Cr and Cr-Co bond lengths are 2.626(2) and 2.673(2) Å, respectively) with Cp ligands at the chromium atoms and a Cb* ligand at the cobalt atom. Complex 5 was characterized by cyclic voltammetry. The thermolysis of complex 4 was studied.