Search Results
Crystal structure of (2S,4S,7S)-7,7-dichloro-4-(1-chloro-1-methylethyl)-1- (2,2,2-trichloroethyl)bicyclo[4.1.0]heptane, C12H16Cl 6
2009, Boualy, B., el Firdoussi, L., Ali, M.A., Karim, A., Spannenberg, A.
C12H16Cl6, orthorhombic, P2 12121 (no. 19), a = 6.0742(3) Å, b = 9.7189(6) Å, c = 26.700(1) Å, V = 1576.2 Å3, Z = 4, Rgt(F) = 0.019, wRref(F2) = 0.045, T= 200 K. © by Oldenbourg Wissenschaftsverlag.
Crystal structure of rac-[1, 2-ethylene-bis(η5-4, 5, 6, 7-tetrahydroindenyl)]1-hafna-4, 5-bis(trimethylsilyl)furan-3-one- tris(pentafluorophenyl)borane, (C20H24)Hf(Me 3SiC2SiMe3CO2)B(C6F 5)3
2009, Beweries, T., Burlakov, V.V., Rosenthal, U., Spannenberg, A.
C47H42BF15HfO2Si2, monoclinic, P121/n1 (no. 14), a = 15.7496(4) Å = 20.4074(5) Å= 16.3115(5) Å, β = 96.313(2)°, V= 5210.9 Å3, Z = 4, Rgt(F) = 0.027, WRref(F 2) = 0.049, T= 200 K. © by Oldenbourg Wissenschaftsverlag.
Crystal structure of (2,3-bis((2R,5R)-2,5-dimethylphosphonalyl)maleic anhydride)-(η4-norbornadiene)-rhodium(I) tetrafluoroborate, [Rh(C7H8)(C16H24O3P 2)] [BF4]
2007, Holz, J., Börner, A., Heller, D., Drexler, H.-J.
C23H32BF4O3P2Rh, orthorhombic, P212121 (no. 19), a = 10.147(2) Å, b = 13.246(3) Å, c = 18.827(4) Å, V = 2530.5 Å3, Z = 4, Rgt(F) = 0.025, wRref(F 2) = 0.067, T = 200 K. © by Oldenbourg Wissenschaftsverlag,.
[N,N-Bis(diphenylphosphino)isopropylamine]dibromidonickel(II)
2009, Hapke, M., Wöhl, A., Peitz, S., Müller, B.H., Spannenberg, A., Rosenthal, U.
The title compound, [NiBr2(C27H27NP2)], was synthesized by the reaction of NiBr2(dme) (dme is 1,2-dimethoxy-ethane) with N,N-bis-(diphenyl-phosphino)isopropyl-amine in methanol/tetra-hydro-furan. The nickel(II) center is coordinated by two P atoms of the chelating PNP ligand, PH2PN(iPr)PPH2, and two bromide ions in a distorted square-planar geometry.
Diacetonitrile[N,N′-bis(2,6-diisopropyl-phenyl)ethane-1,2-diimine] dichloridochromium(II) acetonitrile solvate
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.
Crystal structure of (η4-cycloocta-1,5-dien)-N-(2- (diphenylphosphinooxy)-3-(naphthalen-1-yloxy)propyl)-N-(pentan-3-yl)-1, 1-diphenylphosphinamine-rhodium(I) tetrafluoroborate, [Rh(C8H 12)(C42H43NO2P2)][BF 4]
2007, Dai, Z., Heller, D., Preetz, A., Drexler, H.-J.
C50H55BF4NO2P2Rh, monoclinic, P1211 (no. 4), a = 12.722(3) Å, b = 15.248(3) Å, c = 12.818(3) Å, β = 115.80(3)°, V = 2238.7 Å3, Z = 2, Rgt(F) = 0.036, wRref(F 2) = 0.079, T = 200 K. © by Oldenbourg Wissenschaftsverlag.
Crystal structure of bis(π-allylvalencene)dichlorodipalIadium, [PdCl(C15H23)]2
2009, El Farrouji, A., El Firdoussi, L., Ali, M.A., Karim, A., Spannenberg, A.
C30H46Cl2Pd2, monoclinic, Cl21 (no. 5), a = 22.0083(6) Å, b = 6.1827(2) Å, c = 21.5654(7) Å, β = 91.252(2)°, V= 2933.7 Å3, Z = 4, Rgr(F) = 0.019, wRref(F2) = 0.039, T = 200K. © by Oldenbourg Wissenschaftsverlag, München.
Optical study of orbital excitations in transition-metal oxides
2005, Rückamp, R., Benckiser, E., Haverkort, M.W., Roth, H., Lorenz, T., Freimuth, A., Jongen, L., Möller, A., Meyer, G., Reutler, P., Büchner, B., Revcolevschi, A., Cheong, S.-W., Sekar, C., Krabbes, G., Grüninger, M.
The orbital excitations of a series of transition-metal compounds are studied by means of optical spectroscopy. Our aim was to identify signatures of collective orbital excitations by comparison with experimental and theoretical results for predominantly local crystal-field excitations. To this end, we have studied TiOCl, RTiO3 (R = La, Sm and Y), LaMnO3, Y2BaNiO5, CaCu2O3 and K4Cu4OCl10, ranging from early to late transition-metal ions, from t2g to eg systems, and including systems in which the exchange coupling is predominantly three-dimensional, one-dimensional or zero-dimensional. With the exception of LaMnO3, we find orbital excitations in all compounds. We discuss the competition between orbital fluctuations (for dominant exchange coupling) and crystal-field splitting (for dominant coupling to the lattice). Comparison of our experimental results with configuration-interaction cluster calculations in general yields good agreement, demonstrating that the coupling to the lattice is important for a quantitative description of the orbital excitations in these compounds. However, detailed theoretical predictions for the contribution of collective orbital modes to the optical conductivity (e.g. the line shape or the polarization dependence) are required to decide on a possible contribution of orbital fluctuations at low energies, in particular, in case of the orbital excitations at ≈0.25 eV in RTiO3. Further calculations are called for which take into account the exchange interactions between the orbitals and the coupling to the lattice on an equal footing.
Crystal structure of η5-3,6-di-tert-butyl-4- (tris(pentafluorophenyl)boranyloxycarbonyl)-5-(η5- tetramethylcyclopentadienyl-methyl-9,10,11-trimethyl-bicyclo(6.3.0) undeca-4-en-8,10-dienyl)titanium(III) toluene hemisolvate, Ti(C 51H47BF15O2) · 0.5C 7H8
2008, Spannenberg, A., Burlakov, V.V., Rosenthal, U.
C54.50H51BF15O2Ti, triclinic, P1̄ (no. 2), a = 11.603(2) Å, b = 12.872(3) Å, c = 18.142(4) Å, α = 76.47(3)°, β = 77.99(3)°, γ = 69.13(3)°, V = 2438.2 Å5, Z = 2, Rgt(F) = 0.048, wRobs(F2) = 0.114, T = 200 K. © by Oldenbourg Wissenchaftsverlag.
Crystal structure of strontium praseodum gallium oxide, SrPrGaO4
2000, Gesing, T.M., Uecker, R., Buhl, J.-C.
GaO4PrSr, tetragonal, I4/mmm (No. 139), a = 3.822(1) Å, c = 12.622(2) Å, V = 184.4 Å3, Z = 2, Rgt(F) = 0.028, wR(F2) = 0.082, T = 293 K.