Suwinska K.,Polish Academy of Sciences |
Suwinska K.,Cardinal Stefan Wyszynski University in Warsaw |
Lesniewska B.,Polish Academy of Sciences |
Wszelaka-Rylik M.,Polish Academy of Sciences |
And 3 more authors.
Chemical Communications | Year: 2011
Twelve molecules of β-carbonyl-para-octyl-calixarene assemble in an aggregate containing two types of cavities filled by water molecules and they pack in a cubic structure. Both the aggregates and the packing resemble that observed for inverse micelles. © 2011 The Royal Society of Chemistry.
Eltaief S.,University of Monastir |
Retailleau P.,CNRS Natural Product Chemistry Institute |
Straver L.,Chopinrode 8 |
Ben Hassine B.,University of Monastir
Acta Crystallographica Section E: Structure Reports Online | Year: 2010
In the title salt (2S,4S,8R)-1-butyl-2-[(R)-(hydr-oxy)(6-methoxy-quinolin- 4-yl)meth-yl]-8-vinyl-quinuclidin-1-ium tetra-fluoro-borate, C 24H33N2O2+·BF 4-, the butyl substituent at the 1-position is in an equatorial conformation with respect to the unsubstituted six-membered ring and the four butyl C atoms are almost coplanar with the ring N and vinyl C atoms (r.m.s. deviation = 0.046 Å). In the crystal, the cations are linked by O - H⋯N hydrogen bonds. The F atoms of the tetra-fluoro-borate group are disordered over two sets of site with an occupancy raitio of 0.552 (8):0.448 (8).
Herdtweck E.,TU Munich |
Kornprobst T.,TU Munich |
Sieber R.,TU Munich |
Straver L.,Chopinrode 8 |
Plank J.,TU Munich
Zeitschrift fur Anorganische und Allgemeine Chemie | Year: 2011
From hydrothermal synthesis needle-shaped crystals of [Ca 3(C6H5O7)2(H 2O)2]·2H2O were obtained. The crystal structure was determined by single-crystal X-ray experiments and confirmed by powder data (P1̄ (no. 2) a = 5.9466(4), b = 10.2247(8), c = 16.6496(13) Å, α = 72.213(7)°, β = 79.718(7)°, γ = 89.791(6)°, V = 947.06(13) Å3, Z = 2, R1 = 0.0426, wR2 = 0.1037). The structure was obtained from pseudo merohedrically polysynthetic twinned crystals using a combined data collection approach and refinement processes. The observed three-dimensional network is dominated by eightfold coordinated Ca2+ cations linked by citrate anions and hydrogen bonds between two non-coordinating crystal water molecules and two coordinating water molecules. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Straver L.H.,Chopinrode 8 |
Spek A.L.,University Utrecht
Journal of Applied Crystallography | Year: 2010
The previously described method for absolute structure determination [Hooft, Straver & Spek (2008). J. Appl. Cryst. 41, 96-103] assumes a Gaussian error distribution. The method is now extended to make it robust against poor data with large systematic errors with the introduction of the Student t-distribution. It is shown that this modification makes very little difference for good data but dramatically improves results for data with a non-Gaussian error distribution. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.