Colorless Prisms Research Articles

Fluor-rewitzerite, [(H2O)K]Mn2(Al2Ti)(PO4)4(OF)(H2O)10 ⋅ 4H2O, a new paulkerrite-group mineral, from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, Germany

Abstract. Fluor-rewitzerite, [(H2O)K]Mn2(Al2Ti)(PO4)4(OF)(H2O)10⋅4H2O, is a new monoclinic member of the paulkerrite group, from the Hagendorf-Süd pegmatite, Oberpfalz (Upper Palatinate in English), Bavaria, Germany. It occurs on the walls of vugs in corroded zwieselite, in association with Zn- and Al-bearing earlshannonite, fluorapatite, jahnsite-(CaMnMn) and Al-rich strunzite. Fluor-rewitzerite forms clusters of colourless stubby prisms up to 0.1 mm long that are flattened on {010}; elongated along [100]; and show the forms {100}, {010}, {001}, {111} and {111‾}. Twinning occurs by 2-fold rotation about c. The measured density is 2.42(2) g cm−3. Optically, fluor-rewitzerite crystals are biaxial (+), with α = 1.569(3), β = 1.582(3), γ = 1.602(3) (white light) and 2V(meas) = 78(1)°. The empirical formula from electron microprobe analyses and structure refinement is A1[(H2O)0.85K0.15]Σ1.00A2(K1.00) M1(Mn2+1.50Mg0.09Fe2+0.41)Σ2.00M2+M3(Al1.70Ti4+0.89Fe3+0.42)Σ3.01(PO4)3.99X(O1.09F0.92)Σ2.01(H2O)10⋅4.12H2O. Fluor-rewitzerite has monoclinic symmetry with space group P21/c and unit-cell parameters a = 10.407(1) Å, b = 20.514(2) Å, c = 12.193(1) Å, β = 90.49(2)°, V = 2603.0(4) Å3 and Z = 4. The crystal structure was refined using synchrotron single-crystal data to Robs=0.058 for 6186 reflections with I>3σ(I). Fluor-rewitzerite is the fluoride analogue of rewitzerite, with F dominant over OH at the X sites of the general formula A1A2M12M22M3(PO4)4X2(H2O)10⋅4H2O.

Sperlingite, (H2O)K(Mn2+Fe3+)(Al2Ti)(PO4)4[O(OH)][(H2O)9(OH)]⋅4H2O, a new paulkerrite-group mineral, from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, Germany

Abstract Sperlingite, (H2O)K(Mn2+Fe3+)(Al2Ti)(PO4)4[O(OH)][(H2O)9(OH)]⋅4H2O, is a new monoclinic member of the paulkerrite group, from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, Germany. It was found in corrosion pits of altered zwieselite, in association with columbite, hopeite, leucophosphite, mitridatite, scholzite, orange–brown zincoberaunite sprays and tiny green crystals of zincolibethenite. Sperlingite forms colourless prisms with pyramidal terminations, which are predominantly only 5 to 20 μm in size, rarely to 60 μm and frequently are multiply intergrown and are overgrown with smaller crystals. The crystals are flattened on {010} and slightly elongated along [100] with forms {010}, {001} and {111}. Twinning occurs by rotation about c. The calculated density is 2.40 g⋅cm–3. Optically, sperlingite crystals are biaxial (+), α = 1.600(est), β = 1.615(5), γ = 1.635(5) (white light) and 2V (calc.) = 82.7°. The optical orientation is X = b, Y = c and Z = a. Neither dispersion nor pleochroism were observed. The empirical formula from electron microprobe analyses and structure refinement is A 1[(H2O)0.96K0.04]Σ1.00 A 2(K0.52□0.48)Σ1.00 M 1(Mn2+0.60Mg0.33Zn0.29Fe3+0.77)Σ1.99 M 2+M3(Al1.05Ti4+1.33Fe3+0.62)Σ3.00(PO4)4 X [F0.19(OH)0.94O0.87]Σ2.00[(H2O)9.23(OH)0.77]Σ10.00⋅3.96H2O. Sperlingite has monoclinic symmetry with space group P21/c and unit-cell parameters a = 10.428(2) Å, b = 20.281(4) Å, c = 12.223(2) Å, β = 90.10(3)°, V = 2585.0(8) Å3 and Z = 4. The crystal structure was refined using synchrotron single-crystal data to wRobs = 0.058 for 5608 reflections with I > 3σ(I). Sperlingite is the first paulkerrite-group mineral to have co-dominant divalent and trivalent cations at the M1 sites; All other reported members have Mn2+ or Mg dominant at M1. Local charge balance for Fe3+ at M1 is achieved by H2O → OH– at H2O coordinated to M1.

Ebnerite and epiebnerite: NH4ZnPO4 dimorphs with zeolite-type frameworks from the Rowley mine, Arizona, USA

Abstract Ebnerite and epiebnerite, both with the ideal formula NH4ZnPO4, are new mineral species from the Rowley mine, Maricopa County, Arizona, USA. They occur in an unusual bat-guano-related, post-mining assemblage of phases. Epiebnerite grows epitactically on ebnerite and replaces it. Ebnerite and epiebnerite are found in intimate association with alunite, halite, mimetite, newberyite, sampleite, struvite and wulfenite on hematite-rich quartz–baryte matrix. Crystals of ebnerite are colourless narrow prisms up to ~0.3 mm in length. The streak is white, lustre is vitreous, Mohs hardness is ~2, tenacity is brittle and fracture is splintery. The density is 2.78(2) g⋅cm–3. Ebnerite is optically uniaxial (–) with ω = 1.585(2) and ɛ = 1.575(2). Epiebnerite occurs as colourless prisms or blades, up to about 10 × 3 × 2 μm, in parallel growth forming ribs with serrated edges epitactic on ebnerite prisms. The streak is white, lustre is vitreous, Mohs hardness is probably ~2, tenacity is brittle. The calculated density is 2.851 g⋅cm–3. Epiebnerite is optically biaxial with all indices of refraction near 1.580. Electron microprobe analysis gave the empirical formula [(NH4)0.89K0.06]Σ0.95(Zn0.96Cu0.07)Σ1.03[(P0.97Si0.03)Σ1.00O4] for ebnerite and [(NH4)0.67K0.28]Σ0.95(Zn0.99Cu0.02)Σ1.02(P1.00O4) for epiebnerite. Ebnerite is hexagonal, P63, with a = 10.67051(16), c = 8.7140(2) Å, V = 859.25(3) Å3 and Z = 8. Epiebnerite is monoclinic, P21, with a = 8.796(16), b = 5.457(16), c = 8.960(16) Å, β = 90.34(6)°, V = 430.1(17) Å3 and Z = 4. The structures of ebnerite (R1 = 0.0372 for 1168 Io > 2σI reflections) and epiebnerite (known from synthetic monoclinic NH4ZnPO4) are zeolite-like frameworks based upon corner-sharing linkages between alternating ZnO4 and PO4 tetrahedra with channels in the frameworks hosting the NH4 groups. The two structures are topologically distinct. Ebnerite belongs to the family of ‘stuffed derivatives’ of tridymite, whereas epiebnerite possesses an ABW-type zeolite structure.

New Minerals from the Redmond Mine, North Carolina, USA: V. Finescreekite and Hayelasdiite, Two New Thiosulfate Minerals Containing Cubane-Like Pb4O4 Structural Units

Abstract The new minerals finescreekite, [Pb4(OH)4](S2O3)2 (IMA2022–030), and hayelasdiite, [Pb4O1.5(OH)2.5]2[Cu+5(S2O3)4(S2O2OH)2(H2O)]·4H2O (IMA2022–021), were found in the Redmond mine, Haywood County, North Carolina, USA, where they occur in a highly unusual secondary assemblage that comprises a variety of rare Pb-Zn-Cu sulfates, thiosulfates, and carbonates. Finescreekite was found in close association with anglesite, cubothioplumbite, redmondite, and steverustite. Hayelasdiite was found in close association with anglesite and steverustite. Finescreekite properties: colorless tablets to about 1.5 mm across; white streak; resinous to adamantine luster; brittle; Mohs hardness ∼ 2½; curved, stepped fracture; excellent cleavage on {001}, fair on {100}, {010}, and {110}; 5.675 g/cm3 calculated density; biaxial (−) with α = 2.00(1), β = 2.04(calc), γ = 2.065(calc), 2V = 75.9(5)°. Hayelasdiite properties: colorless prisms and blades to about 0.5 mm in length; white streak; vitreous to subadamantine luster; brittle; Mohs hardness ∼ 2½; curved fracture; perfect cleavage on {010}; 4.909 g/cm3 calculated density; biaxial (−) with α = 1.89(1), β = 1.95(calc), γ = 1.97(calc), 2V = 58(5)°. Electron probe microanalyses provided the empirical formulae [Pb4(OH)4](S2O3)1.76(SO4)0.24 and [Pb4.00O1.5(OH)2.5]2[Cu+5.00(S2O3)3.24(SO4)0.76(S2O2OH)2(H2O)]·4H2O for finescreekite and hayelasdiite, respectively. Finescreekite is Orthorhombic, P212121, a = 8.2330(9), b = 10.7128(13), c = 14.8256(13) Å, V = 1307.6(2) Å3, and Z = 4. Hayelasdiite is triclinic, P1̄, a = 7.52089(15), b =14.9345(3), c = 17.9895(13) Å, α = 106.727(8), β = 90.966(6), γ = 90.031(6)°, V = 1934.79(16) Å3, and Z = 2. The structures of finescreekite (R1 = 0.061 for 1440 I > 2σI) and hayelasdiite (R1 = 0.055 for 5636 I > 2σI) both contain cubane-like Pb4O4 clusters, [Pb4(OH)4]4+ in finescreekite and [Pb4O1.5(OH)2.5]2.5+ in hayelasdiite. The structure of hayelasdiite also contains a decorated double chain with the formula [Cu+5(S2O3)4(S2O2OH)2(H2O)]5−.

Mallestigite, Pb3Sb(SO4)(AsO4)(OH)6·3H2O, from the type locality – new data, crystal structure, and structural relationships

A report of the supergene mineral mallestigite, Pb3Sb5+(SO4)(AsO4)(OH)6·3H2O, from the type locality Neufinkenstein-Grabanz district, Mallestiger Mittagskogel, Carinthia, Austria, is given in order to close gaps that have been left open since its first description. At the type locality, the dump of an abandoned small copper-lead-zinc mine, the mineral occurs frequently in up to ⁓2 mm long clear colourless idiomorphic hexagonal prisms {100} terminated by the bipyramid {101}. Details of the occurrence, paragenesis, physical properties, a FTIR spectrum and X-ray powder diffraction data are reported. Chemical analysis in a scanning electron microscope in conjunction with a crystal structure analysis gave the empirical formula Pb3.02Sb1.06(SO4)0.96(AsO4)0.97(OH)6·3H2O. An ab-initio crystal structure determination with CCD diffractometer data, MoKα radiation, and a nearly untwinned crystal proved that mallestigite is hexagonal, space group P63, a = 8.9326(4), c = 11.1044(5) Å, V = 767.33(8) Å3, Z = 2, and gave a final R1 = 0.0184 for 1632 independent reflections with I > 2σ(I). Mallestigite belongs to the fleischerite group. The structure is built up from [Sb5+(OH)6]1– octahedra which are linked by triplets of edge-sharing Pb2+ into chains [Pb3Sb(OH)6]5+ extending along a 63 axis. Each three of such chains are bridged by triplets of H2O and by rows of SO42– and AsO43– tetrahedra alternating along a 3-fold axis and showing very different links to the Pb atom. Pb2+ is in a strongly distorted one-sided [9]-coordination by O atoms that makes the structure clearly hemimorphic. Structural relationships to the fleischerite group minerals schaurteite, genplesite, despujolsite and fleischerite as well as to synthetic Ba3Sn4+(SeO4)2(OH)6·3H2O are outlined and changes in the space group symmetry of despujolsite (P6¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline6$$\\end{document}2c → P63/mmc) and fleischerite (P6¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline6$$\\end{document}2c → P63) are proposed.

New Minerals from the Redmond Mine, North Carolina, USA: II. Cubothioplumbite and Hexathioplumbite, Two New Minerals Containing the Cubane-Like [Pb4(OH)4]4+ Structural Unit

Abstract The new minerals cubothioplumbite (IMA2021-091) and hexathioplumbite (IMA2021-092), both with the ideal formula [Pb4(OH)4]Pb(S2O3)3, were found in the Redmond mine, Haywood County, North Carolina, USA, where they occur together in a highly unusual secondary assemblage that comprises a variety of rare Pb-Zn-Cu sulfates, thiosulfates, and carbonates. Cubothioplumbite has the following properties: yellow equant crystals to about 0.5 mm; white streak; adamantine luster; brittle; Mohs hardness 3; conchoidal fracture; no cleavage; 5.748 g/cm3 calculated density; isotropic with n > 2.00. Hexathioplumbite has the following properties: colorless hexagonal prisms to about 1 mm; white streak; adamantine luster; brittle; Mohs hardness 2½; curved fracture; no cleavage; 5.531 g/cm3 calculated density; uniaxial (−) with ω = 2.005(5) and ε = 1.995(5). Electron probe microanalyses provided the empirical formulae [Pb4(OH)4]Pb(S2O3)2.72(SO4)0.28 and [Pb4(OH)4]Pb(S2O3)2.68(SO4)0.32 for cubothioplumbite and hexathioplumbite, respectively. Cubothioplumbite is cubic, Pa, a = 14.9179(13) Å, V = 3319.9(9) Å3, and Z = 8. Hexathioplumbite is hexagonal, P63, a = 10.7213(10), c = 8.6541(6) Å, V = 861.49(17) Å3, and Z = 2. The structures of cubothioplumbite (R1 = 0.0354 for 1090 I > 2σI) and hexathioplumbite (R1 = 0.0791 for 1062 I > 2σI) both contain cubane-like [Pb4(OH)4]4+ structural units.

Синтез и рострегулирующая активность аммонийных солей малеамовых кислот

The article describes the synthesis of ammonium salts of maleamic acids containing amino acid fragments. At the first stage, the interaction of maleic anhydride with aliphatic and aromatic amino acids yielded the corresponding maleamic acids. Glycine, α-alanine, ε-aminocaproic, para-aminosalicylic, ortho-, meta- and para-aminobenzoic acids were used as amino acids. In the case of aliphatic amino acids, the process was carried out in an aqueous or aqueous-acetone (2: 1) medium. For aromatic amino acids, acetone was used as a solvent. As weakly exothermic reactions progressed, colorless finely crystalline or light yellow friable precipitates of the corresponding maleamic acids precipitated. In the second stage, the suspension of synthesized maleamic acids in an aqueous medium was treated with a calculated amount of 25% aqueous ammonia solution. With further isothermal evaporation of aqueous solutions, ammonium salts crystallize in the form of hygroscopic colorless prisms or fine crystalline dense precipitates. The structure of the newly obtained compounds was confirmed by IR and 1H NMR spectroscopy. In order to identify the biological activity of the synthesized salts, the effect of their aqueous solutions of various concentrations on the germination energy (GE) and laboratory germination (LG) of the seeds of spring barley cultivar «Elf», winter rye of the «Bezenchukskaya 87» variety and wheat was studied spring varieties «Moskovskaya 35». The determination of GE and LG drug in experimental and control samples showed that 0.01% - 0.001% aqueous solutions have a stimulating effect on seed germination compared to control. The best effect is achieved with pre-sowing seed treatment with 0.01% aqueous solutions of ammonium salts of maleic acids, which allows to increase germination by 9-26%.

4-(4-Hy-droxy-phenyl)-2,2,4-trimethyl-7,8-benzo-thia-chroman, a fused-ring counterpart of thia-Dianin's compound.

The title compound, C22H22OS [systematic name: 4-(1,3,3-trimethyl-2,3-di-hydro-1H-4-thia-phenanthren-1-yl)phenol], crystallizes unsolvated from nitro-methane as colourless prisms (m.p. 425-427 K) in the polar monoclinic space group Ia with Z' = 2 (mol-ecules A and B). Both independent mol-ecules possess a very similar proximal conformation, this referring to the juxtaposition of the 4-hy-droxy-phenyl substituent with respect to the syn-related methyl group. In the crystal, mol-ecule A is linked to mol-ecule B by an O-H⋯O hydrogen bond. In turn, mol-ecule B exhibits a weak O-H⋯π inter-action with the phenolic group of mol-ecule A related by a-glide symmetry. Together, these lead to [100] chains.

Cuparane sesquiterpenes from Laurencia natalensis Kylin as inhibitors of alpha-glucosidase, dipeptidyl peptidase IV and xanthine oxidase

The unexplored southern African red marine alga Laurencia natalensis was studied in a search for new enzyme inhibitors. A new cuparane sesquiterpenoid, 8-deoxyalgoane (1) along with two known sesquiterpenoids namely 1-deacetoxyalgoane (2) and algoane (3) were isolated from the MeOH:DCM extract using silica column chromatography with an hexane:EtOAc solvent system. Algoane was obtained as colourless prisms and structures of the three compounds were confirmed by NMR. The three compounds were tested for enzyme inhibitory activities against alpha-glucosidase and dipeptidyl peptidase IV (DPP-IV). Algoane was also tested against xanthine oxidase. In addition, molecular properties were determined to establish drug likeness, and other physico-chemical properties. This is the first report on the chemistry and biological properties of L. natalensis.

Crystal structure of potassium (1S)-d-lyxit-1-yl-sulfonate monohydrate.

The title compound, K(+)·C5H11O8S(-)·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy-droxy-methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter-molecular O-H⋯O hydrogen bonding.

Thermal plasma source for processing of MoO3 crystals

Simple original technique for fabrication of molybdenum trioxide MoO3 crystals during electric arc discharge directly from metallic molybdenum was proposed. The vertically oriented free-burning arc was ignited between the end surfaces of metallic molybdenum non- cooled electrodes. Molybdenum oxide crystals were deposited on side surface of bottom electrode (anode). Observation of crystals formation zone was used for determination of main process stages. The resulting products were studied by X-rays diffraction and optical microscopy methods. Investigations indicate, that self-organizing vapor-deposition process of MoO3 crystals formation has place. The resulting product is colorless sparkling prisms and platelets, which mainly consist of orthorhombic a-MoO3 phase. Optical microscopy indicates formation of closely packed feather-like pins structures by vapor-solid process.

Torrecillasite, Na(As,Sb)43+O6Cl, a new mineral from the Torrecillas mine, Iquique Province, Chile: description and crystal structure

AbstractThe new mineral torrecillasite (IMA2013-112), Na(As,Sb)43+O6Cl, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, cinnabar, gypsum, halite, lavendulan, magnesiokoritnigite, marcasite, quartz, pyrite, scorodite, wendwilsonite and other potentially new As-bearing minerals. Torrecillasite occurs as thin colourless prisms up to 0.4 mm long in jack-straw aggregates, as very thin fibres in puff balls and as massive intergrowths of needles. Prisms are elongated on [100] with diamond-shaped cross-section and irregular terminations. Crystals are transparent, with adamantine lustre and white streak. The Mohs hardness is 2½, tenacity is brittle and fracture is irregular. Cleavage on (001) is likely. The calculated density is 4.056 g cm−3. Optically, torrecillasite is biaxial (−) with α = 1.800(5), β = 1.96(1), γ = 2.03(calc.) (measured in white light). The measured 2V is 62.1(5)°, no dispersion or pleochroism were observed, the optical orientation isX=c,Y=b,Z=a. The mineral is very slowly soluble in H2O, slowly soluble in dilute HCl and rapidly soluble in concentrated HCl. The empirical formula, determined from electron-microprobe analyses, is (Na1.03Mg0.02)∑1.05(As3.39Sb0.62)∑4.01O6.07Cl0.93. Torrecillasite is orthorhombic,Pmcn, a= 5.2580(9),b= 8.0620(13),c= 18.654(3) Å,V= 790.7(2) Å3andZ= 4. The eight strongest X-ray powder diffraction lines are [dobsÅ(I)(hkl)]: 4.298(33)(111), 4.031(78)(014,020), 3.035(100)(024,122), 2.853(39)(115,123), 2.642(84)(124,200), 2.426(34)(125), 1.8963(32)(225) and 1.8026(29)(0·1·10,233). The structure, refined toR1= 4.06% for 814Fo>4σFreflections, contains a neutral, wavy As2O3layer parallel to (001) consisting of As3+O3pyramids that share O atoms to form six-membered rings. Successive layers are flipped relative to one another and successive interlayer regions contain alternately either Na or Cl atoms. Torrecillasite is isostructural with synthetic orthorhombic NaAs4O6Br.

Crystal structure of 6-(4-chlorophenoxy)-1-methylindoline-2,3-dione, C15H10CINO3

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Preparation and structural analysis of (±)-threo-ritalinic acid

Hydrolysis of the methyl ester (±)-threo-methyl phenidate afforded the free acid in 40% yield, viz. (±)-threo-ritalinic acid, C13H17NO2. Hydrolysis and subsequent crystallization were accomplished at pH values between 5 and 7 to yield colourless prisms which were analysed by X-ray crystallography. Crystals of (±)-threo-ritalinic acid belong to the P21/n space group and form intermolecular hydrogen bonds. An antiperiplanar disposition of the H atoms of the (HOOC-)CH-CHpy group (py is pyridine) was found in both the solid (diffraction analysis) and solution state (NMR analysis). It was also determined that (±)-threo-ritalinic acid conforms to the minimization of negative gauche(+)-gauche(-) interactions.

Nizamoffite, Mn2+Zn2(PO4)2(H2O)4, the Mn analogue of hopeite from the Palermo No. 1 pegmatite, North Groton, New Hampshire

Nizamoffite, ideally Mn2+Zn2(PO4)2(H2O)4, is a new mineral from the Palermo No.1 pegmatite in North Groton, Grafton County, New Hampshire, U.S.A. It formed as the result of secondary alteration of primary triphylite and associated sphalerite. The crystals occur as colorless prisms up to 1 mm in length and 0.5 mm in diameter. The prisms are elongated and lightly striated parallel to [001] and exhibit the forms {100}, {010}, {230}, {011}, {031}, and {111}. The mineral is transparent and has a white streak, vitreous luster, Mohs hardness of about 3½, brittle tenacity, irregular fracture, and three cleavages: perfect on {010}, good on {100}, and fair on {001}. The measured and calculated densities are 3.00(1) and 2.961 g/cm3, respectively. It is optically biaxial (−), α = 1.580(1), β = 1.590(1), γ = 1.591(1) (white light), 2 V meas = 28(1)°, and 2 V calc = 35°. Nizamoffite exhibits strong dispersion, r 4σ F ) contains corner-sharing zigzag chains of ZnO4 tetrahedra along [001]. The chains are connected by corner sharing with PO4 tetrahedra to form sheets parallel to {010}. Three of the four PO4 vertices link to ZnO4 tetrahedra in the sheet, while the fourth links to an octahedron between the sheets. Each octahedron links to one tetrahedron from each of two adjacent sheets, thereby linking the sheets in the [010] direction. The octahedron contains Zn in hopeite and Mn in nizamoffite.

X-Ray Structure of the Key Synthetic Intermediate of a Cancer-Related Sialyl-Tn Antigen Analogue

We report herein the synthesis and the X-ray crystal structure of 2-azido-2-deoxy-3,4-O-isopropylidene-α-d-galactopyranosyl-N-oxyphthalimide 3 which is the key-precursor of a cancer-related STn antigen analogue 5. Compound 3 crystallizes from a mixture of dichloromethane/pentane as colorless orthorhombic needles in P2 1 2 1 2 space group with the following cell parameters: a = 14.039(2) A; b = 16.574(3) A; c = 8.038(1) A. The hexapyranose ring of 3 adopts a twisted boat according to the Cremer and Pople puckering parameters (Cremer and Pople, J Am Chem Soc 97:1354, 1975) whereas the structure determination of the corresponding deprotected intermediate 4 (orthorombic colorless prisms, P2 1 2 1 2 1 space group, a = 4.927(3) A; b = 13.423(2) A; c = 22.744(3) A) has revealed a quasi perfect chair. We report herein the synthesis and the X-ray crystal structure of 2-azido-2-deoxy-3,4-O-isopropylidene-α-d-galactopyranosyl-N-oxyphthalimide 3 which is the key-precursor of a cancer-related STn antigen analogue 5.

Two polymorphs of a lead(II) complex with 8-hydroxy-2-methylquinoline and thiocyanate

Two distinct polymorphs of bis(mu(2)-methylquinolin-8-olato)-kappa(3)N,O:O;kappa(3)O:N,O-bis[(isothiocyanato-kappaN)lead(II)], [Pb(2)(C(10)H(8)NO)(2)(NCS)(2)], (I), forming dinuclear complexes from a methanolic solution containing lead(II) nitrate, 2-methylquinolin-8-ol (M-Hq) and KSCN, crystallized concomitantly as colourless prisms [form (Ia)] and long thin colourless needles [form (Ib)]. In both cases, the complexes lie across a centre of inversion. The polymorphs differ substantially in their conformation and in their interactions, viz. Pb...S and pi-pi for form (Ia) and Pb...S, Pb...pi and C-H...pi for form (Ib).

Syntheses, crystal structures, and polymorphism of quaternary pyrrolidinium chlorides

The syntheses, properties, and X-ray crystal structures of 1-methyl-1-propylpyrrolidinium chloride1, 1-allyl-1-methylpyrrolidinium chloride2, and 1-methyl-1-propargylpyrrolidinium chloride3 are described. Colorless plates of 1 (C8H18ClN) crystallize in the orthorhombic space groupPnab with Z = 8 and unit cell parameters a = 10.0354(11) A, b = 13.254(2) A, c = 14.6231(16) A. Colorless prisms of 2 (C8H16ClN) crystallize in the monoclinic space groupP21/c with Z = 4 and unit cell parameters a = 6.4857(10) A, b = 12.005(3) A, c = 12.526(2) A, and β=102.746(13)°. Colorless needles of 3 (C8H14ClN) crystallize in the monoclinic space groupP21/n with Z = 4 and unit cell parameters a = 8.4849(14) A, b = 8.1271(16) A, c = 13.501(2) A, and β=100.408(13)°. The five-membered ring adopts a twisted conformation in 1 but an N-envelope in 2 and 3. The salts form networks of weak C–H…Cl−hydrogen bonds. Hot stage microscopy, differential scanning calorimetry and temperature-controlled X-ray powder diffractometry revealed that each of the three compounds exists in at least two different crystal forms.

1,1′-(Ethenylidene)bis(4-chlorobenzene)

The title compound, C14H10Cl2, crystallizes as colourless prisms with two symmetry-independent molecules in the unit cell. Numerous intermolecular C-H...pi interactions dominate in the crystal structure, where C-H...Cl and long Cl...Cl contacts are also observed.

Tricalysiolide G and tricalysiols A and B: rearranged ent-kaurane-type and ent-kaurane-type diterpenoids from the leaves of Tricalysia dubia (Lindl.) Ohwi

Three rearranged ent-kaurane diterpenes with the cafestol-type framework have been isolated from the leaves of Tricalysia dubia. Two were found to be known diterpenoids, tricalysiolides B and C. Tricalysiolide B was isolated as colorless prisms in this experiment and its three-dimensional structure was determined by X-ray crystallography. The remaining diterpenoid was a new compound and was named tricalysiolide G. Two new ent-kaurane-type diterpenoids, given the trivial names tricalysiol A and tricalysiol B, were also isolated. The structures of the new compounds were elucidated from spectroscopic evidence.