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- ItemMethyl 5-chloro-2-hydr-oxy-3-(4-methoxyphenyl)-4,6-dimethylbenzoate(Chester : International Union of Crystallography, 2009) Adeel, M.; Ali, I.; Langer, P.; Villinger, A.In the title compound, C17H17ClO4, the dihedral angle between the mean planes of the two benzene rings is 65.92 (5)°. The methyl ester group lies within the ring plane [deviations of O atoms from the plane = -0.051 (2) and 0.151 (2) Å] due to an intra-molecular O - H⋯O hydrogen bond. In the crystal, molecules are held together by rather weak non-classical inter-molecular C - H⋯O hydrogen bonds, resulting in dimeric units about inversion centers, forming eight- and ten-membered ring systems as R22(8) and R2 2(10) motifs. © Adeel et al. 2009.
- Item[1-Dimethylsilyl-2-phenyl-3-(η5-tetramethylcyclopentadienyl) prop-1-en-1-ylκC1](n5-pentamethylcyclopentadienyl)- titanium(III)(Chester : International Union of Crystallography, 2009) Lamač, M.; Spannenberg, A.; Arndt, P.; Rosenthal, U.The title compound, [Ti(C10H15)(C20H 26Si)], was obtained from the reaction of [Ti{5: 1-C5Me4(CH2)}(5-C 5Me5)] with the alkynylsilane PhC2SiMe 2H. The complex crystallizes with two independent mol-ecules in the asymmetric unit, which differ in the conformation of the propenyl unit, resulting in their having opposite helicity. No inter-molecular inter-actions or inter-actions involving the Si- H bond are present. The observed geometrical parameters are unexceptional compared to known structures of the same type.
- ItemRedetermination of EuScO3(Chester : International Union of Crystallography, 2009) Kahlenberg, V.; Maier, D.; Veličkov, B.Single crystals of europium(III) scandate(III), with ideal formula EuScO3, were grown from the melt using the micro-pulling-down method. The title compound crystallizes in an ortho-rhom-bic distorted perovskite-type structure, where Eu occupies the eightfold coordinated A sites (site symmetry m) and Sc resides on the centres of corner-sharing [ScO6] octa-hedra (B sites with site symmetry ). The structure of EuScO3 has been reported previously based on powder diffraction data [Liferovich & Mitchell (2004). J. Solid State Chem. 177, 2188-2197]. The results of the current redetermination based on single-crystal diffraction data shows an improvement in the precision of the structral and geometric parameters and reveals a defect-type structure. Site-occupancy refinements indicate an Eu deficiency on the A site coupled with O defects on one of the two O-atom positions. The crystallochemical formula of the investigated sample may thus be written as A(0.032Eu0.968)BScO2.952.
- Item(μ5-Cyclo-penta-dien-yl)bis-(triphenyl-phosphane)cobalt(I) -toluene-n-hexane (1/0.20/0.25)(Chester : International Union of Crystallography, 2008) Hapke, M.; Spannenberg, A.The title compound, [Co(C5H5)(C18H15P)2]·0.2C7H8·0.25C6H14, was synthesized by the reaction of cobaltocene, Cp2Co, with elemental lithium in tetra-hydro-furan in the presence of two equivalents of PPh3. The mol-ecular structure displays a cobalt(I) center in a distorted trigonal-planar coordination environment, with one Cp and two phosphane ligands. There are two crystallographically independent mol-ecules in the asymmetric unit besides the disordered solvent molecules.
- ItemRedetermination of terbium scandate, revealing a defect-type perovskite derivative(Chester : International Union of Crystallography, 2008) Veličkov, B.; Kahlenberg, V.; Bertram, R.; Uecker, R.The crystal structure of terbium(III) scandate(III), with ideal formula TbScO3, has been reported previously on the basis of powder diffraction data [Liferovich & Mitchell (2004). J. Solid State Chem. 177, 2188-2197]. The current data were obtained from single crystals grown by the Czochralski method and show an improvement in the precision of the geometric parameters. Moreover, inductively coupled plasma optical emission spectrometry studies resulted in a nonstoichiometric composition of the title compound. Site-occupancy refinements based on diffraction data support the idea of a Tb deficiency on the A site (inducing O defects on the O2 position). The crystallochemical formula of the investigated sample thus may be written as A(0.04Tb0.96) BScO2.94. In the title compound, Tb occupies the eightfold- coordinated sites (site symmetry m) and Sc the centres of corner-sharing [ScO6] octa-hedra (site symmetry ). The mean bond lengths and site distortions fit well into the data of the remaining lanthanoid scandates in the series from DyScO3 to NdScO3. A linear structural evolution with the size of the lanthanoid from DyScO3 to NdScO3 can be predicted.
- ItemP-[N-(Diphenyl-phospho-rothio-yl)iso-propyl-amino]-N-isopropyl-P-phenyl- thio-phosphinic amide(Chester : International Union of Crystallography, 2009) Peulecke, N.; Aluri, B.R.; Wöhl, A.; Spannenberg, A.; Al-Hazmi, M.H.The title compound, C24H30N2P2S2, was obtained by the reaction of Ph2PN(iPr)P(Ph)N(iPr)H with elemental sulfur in tetra-hydro-furan. In the solid state, intra-molecular N - H⋯S hydrogen bonding influences the mol-ecular conformation; a P - N - P - N torsion angle of 2.28 (9)° is observed. The two phenyl rings attached to one P atom form a dihedral angle of 74.02 (4)°.
- ItemBis[N,N′-bis-(2,6-diisopropylphenyl)ethane-1,2-diimine] -1κ2 N,N′;2κ2 N,N′-tri - Trichlorido-1:2κ6 Cl:Clchlorido-1Cltetrahydrofuran- 2Odichromium(II) dichloromethane 4.5-solvate(Chester : International Union of Crystallography, 2009) Peitz, S.; Peulecke, N.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.In the mol-ecular structure of the title compound, [Cr2Cl4(C 26H36N2)2(C4H8O)] ·4.5CH2Cl2, the two CrII centers are bridged by three Cl atoms, forming a dinuclear complex. Each CrII center is coordinated by one chelating bis-(2,6-diisopropyl-phen-yl)ethane-1,2-diimine ligand via both N atoms. An additional chloride ion binds to one chromium center, whereas an additional tetra-hydro-furan mol-ecule coordinates to the second CrII center. The coordination geometry at each CrII center can be best described as distorted octa-hedral.
- Item1,1,2,2-Tetra-phenyl-15-diphosphane 1-sulfide(Chester : International Union of Crystallography, 2009) Aluri, B.R.; Peitz, S.; Wöhl, A.; Peulecke, N.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.In the title mol-ecule, C24H20P2S, the P - P bond length is 2.2263 (5) Å. The two phenyl rings attached to the three- and five-coordinated P atoms, respectively, form dihedral angles of 56.22 (5) and 71.74 (5)°.
- ItemDiacetonitrile[N,N′-bis(2,6-diisopropyl-phenyl)ethane-1,2-diimine] dichloridochromium(II) acetonitrile solvate(Chester : International Union of Crystallography, 2009) Peitz, S.; Peulecke, N.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.The title compound, [CrCl2(CH3CN)2(C 26H36N2)]·CH3CN, was synthesized by the reaction of CrCl2(THF)2 with N,N′-bis-(2,6- diisopropyl-phen-yl)ethane-1,2-diimine in dichloro-methane/acetonitrile. The chromium center is coordinated by two N atoms of the chelating diimine ligand, two chloride ions in a trans configuration with respect to each other, and by two N atoms of two acetonitrile mol-ecules in a distorted octa-hedral geometry.
- ItemModelling carbon dynamics from urban land conversion: Fundamental model of city in relation to a local carbon cycle(London : Biomed Central, 2006) Svirejeva-Hopkins, A.; Schellnhuber, H.-J.Background: The main task is to estimate the qualitative and quantitative contribution of urban territories and precisely of the process of urbanization to the Global Carbon Cycle (GCC). Note that, on the contrary to many investigations that have considered direct anthropogenic emission of CO2(urbanized territories produce ca. 96-98% of it), we are interested in more subtle, and up until the present time, weaker processes associated with the conversion of the surrounding natural ecosystems and landscapes into urban lands. Such conversion inevitably takes place when cities are sprawling and additional "natural" lands are becoming "urbanized". Results: In order to fulfil this task, we first develop a fundamental model of urban space, since the type of land cover within a city makes a difference for a local carbon cycle. Hence, a city is sub-divided by built-up, "green"(parks, etc.) and informal settlements (favelas) fractions. Another aspect is a sub-division of the additional two regions, which makes the total number reaching eight regions, while the UN divides the world by six. Next, the basic model of the local carbon cycle for urbanized territories is built. We consider two processes: carbon emissions as a result of conversion of natural lands caused by urbanization; and the transformation of carbon flows by "urbanized" ecosystems; when carbon, accumulated by urban vegetation, is exported to the neighbouring territories. The total carbon flow in the model depends, in general, on two groups of parameters. The first includes the NPP, and the sum of living biomass and dead organic matter of ecosystems involved in the process of urbanization, and namely them we calculate here, using a new more realistic approach and taking into account the difference in regional cities' evolution. Conclusion: There is also another group of parameters, dealing with the areas of urban territories, and their annual increments. A method of dynamic forecasting of these parameters, based on the statistical regression model, was already suggested; nevertheless we shall further develop a new technique based on one idea to use the gamma-distribution. This will allow us to calculate the total carbon balance and to show how urbanization shifts it. © 2006 Svirejeva-Hopkins and Schellnhuber; licensee BioMed Central Ltd.