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Darmstadt, Germany

Gatta G.D.,University of Milan | Gatta G.D.,CNR Institute of Crystallography | Scheidl K.S.,University of Vienna | Pippinger T.,University of Vienna | And 4 more authors.
Microporous and Mesoporous Materials

The compressional behavior and the P-induced crystal-fluid interaction of a natural paulingite-K have been explored on the basis of in-situ single-crystal and powder X-ray diffraction, and in-situ single-crystal Raman spectroscopy with a diamond anvil cell and a series of diverse pressure-transmitting fluids (i.e., silicone-oil, methanol:ethanol = 4:1, methanol:ethanol:water = 16:3:1). No evidence of any phase transition was observed within the P-range investigated, independent on the used P-fluids. The compressional behavior of paulingite is significantly different in response to the different nature of the P-fluids. A drastically lower compressibility is observed when the zeolite is compressed in methanol:ethanol or, even more noticeably, in methanol:ethanol:water mix. We ascribe this phenomenon to the different crystal-fluid interaction at high pressure: (1) silicone-oil is a "non-penetrating" P-medium, because of its polymeric nature, whereas (2) methanol-ethanol and water are "penetrating" P-fluids. The P-induced penetration processes appear to be completely reversible on the basis of the X-ray diffraction data alone. The Raman spectra collected after the high-pressure experiments show, unambiguously, that a residual fraction of methanol (and/or ethanol and probably even extra H2O) still resides in the zeolitic sub-nanocavities; such molecules are spontaneously released after a few days at atmospheric pressure. The actual compressibility of paulingite-K is that obtained by the compression experiment in silicone-oil, with an isothermal bulk modulus K0 = β0 -1 = 18.0(1.1) GPa. Paulingite appears to be one of the softest zeolite ever found. © 2014 Elsevier Inc. All rights reserved. Source

Frey G.D.,TU Munich | Frey G.D.,TU Darmstadt | Hoffmann S.D.,STOE and Cie GmbH
Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences

Ferrocenyl aryl ethers can be synthesized in good yields by Cu(I)/phosphine-catalyzed coupling reactions from iodoferrocene or 1,1′-dibromoferrocene and various phenols in toluene, using Cs2CO3 or K3PO4 as a base. For the first time a solid-state structure of a ferrocenyl-1,1′-diaryl ether [1,1′-di(4-tert-butylphenoxy)ferrocene] has been determined from single-crystal X-ray data. The mixed ferrocenyl aryl ether 1-(4-tert-butylphenoxy)-1′-(2,4-dimethylphenoxy)ferrocene was prepared in a two-step synthetic protocol. Source

Depla A.,Catholic University of Leuven | Verheyen E.,Catholic University of Leuven | Veyfeyken A.,Catholic University of Leuven | Gobechiya E.,Catholic University of Leuven | And 4 more authors.
Physical Chemistry Chemical Physics

The hydrothermal crystallizations of two zeolite topologies (FAU and LTA) have been studied by simultaneous UV-Raman spectroscopy and X-ray diffraction in a home built setup. A wide angle X-ray diffractometer has been redesigned and combined with Raman components. The results revealed, despite similar structures of the starting gels, different aluminosilicate species evolved in the two systems, prior to emerging Bragg scattering. Based on this the sodalite cage could be ruled out as a common building unit for both frameworks. © the Owner Societies 2011. Source

Meyer J.,Karlsruhe Institute of Technology | Meyer J.,STOE and Cie GmbH | Kuzu I.,Karlsruhe Institute of Technology | Kuzu I.,University of Marburg | And 2 more authors.
Zeitschrift fur Anorganische und Allgemeine Chemie

Reactions of HC(pz)3 and HC(4-Mepz)3 with MgBu 2 and Mg{N(SiMe3)2}2 gave the zwitterionic complexes [Mg{C(pz)3}2] (2) and [Mg{C(4-Mepz)3}2] (4), respectively, containing "free" pyramidal carbanions (pz = pyrazolyl). The solid-state structure of 2 has been determined. Reactions of 2 and 4 as well as the recently reported homo- and heteroleptic complexes [Mg{C(3, 5-Me2pz) 3}2] (1) and [Mg{C(3, 5-Me2pz) 3}{C(pz)3}] (3) with the Lewis acid AlEt3 furnished the bi- and trimetallic complexes [Mg{C(pz)3} 2(AlEt3)2] (5), [Mg{C(pz)3} (AlEt3){C(3, 5-Me2pz)3}] (6), and [Mg{C(4-Mepz)3}2(AlEt3)2] (7). Based on NMR spectroscopic investigations, including an X-ray structural analysis on single crystals of 5, only the parent tris(pyrazolyl)methanide {C(pz) 3}- and the 4-methyl-substituted ligand scaffolds form C-bound adducts with the Lewis acid. By quantifying the steric bulk of κ3N-coordinated {C(pz)3}- it could be shown that its steric features are similar to those of bulky phosphine ligands. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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