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- ItemHigh-resolution characterization of the forbidden Si 200 and Si 222 reflections(Chester : International Union of Crystallography, 2015) Zaumseil, P.The occurrence of the basis-forbidden Si 200 and Si 222 reflections in specular X-ray diffraction !–2 scans is investigated in detail as a function of the inplane sample orientation. This is done for two different diffractometer types with low and high angular divergence perpendicular to the diffraction plane. It is shown that the reflections appear for well defined conditions as a result of multiple diffraction, and not only do the obtained peaks vary in intensity but additional features like shoulders or even subpeaks may occur within a 2 range of about 2.5 . This has important consequences for the detection and verification of layer peaks in the corresponding angular range.
- Item1,1-Bis(diphenylphosphoryl)hydrazine(Chester : International Union of Crystallography, 2018) Höhne, Martha; Aluri, Bhaskar R.; Spannenberg, Anke; Müller, Bernd H.; Peulecke, Normen; Rosenthal, UweThe title compound, C24H22N2O2P2, contains a diphosphazane backbone, as well as a hydrazine entity. The P—N—P diphosphazane unit and the N-amine N atom are almost coplanar, and the O atoms of the Ph2P(O) units are oriented trans to each other with respect to the P...P axis. In the crystal, centrosymmetrically related molecules are linked into dimers by pairs of N—H...O hydrogen bonds, forming rings of graph-set motif R22(10).
- ItemDi-μ-chlorido-bis({4-[bis(trimethylsilyl)amino]-6-chloro-2,2,8,8-tetramethyl-5,7-bis(trimethylsilyl)-3,5,7-triaza-4,6-diphospha-2,8-disilanon-3-en-4-ido-κ2P,P′}palladium(II)) diethyl ether disolvate(Chester : International Union of Crystallography, 2016) Höhne, Martha; Müller, Bernd H.; Spannenberg, Anke; Rosenthal, UweThe title compound, [Pd2(C18H54Cl2N4P2Si6)2Cl2]·2C4H10O, features a dinuclear chloride-bridged palladium complex bearing two equivalents of the novel monoanionic mixed valent (λ3-P)—N—(λ5-P) ligand. A metal catalyzed coupling of two aminoiminophosphines and a shift of one chlorine from the metal to the phosphorus results in the (λ3-P)—N—(λ5-P) ligand. The molecule contains a planar bimetallic Pd2Cl2 core with a crystallographic centre of inversion at the mid-point of the Pd⋯Pd line. The Pd atoms are in a distorted square-planar arrangement, where the P/Pd/P and Cl/Pd/Cl planes are twisted with respect to each other by a dihedral angle of 7.57 (4)°. The P—Pd—P bite angle is 71.380 (18)°. Intramolecular C—H⋯Cl interactions are observed. In the crystal, the diethyl ether solvent molecule is disordered over two sites, with an occupancy ratio of 0.788 (5):0.212 (5).
- ItemA second polymorph of 3,4-bis(6-bromopyridin-3-yl)-1,2,5-thiadiazole(Chester : International Union of Crystallography, 2016) Becker, Lisanne; Altenburger, Kai; Spannenberg, Anke; Arndt, Perdita; Rosenthal, UweThe title compound, C12H6Br2N4S, a second polymorph in the triclinic space group P-1, is presented. As in the earlier reported monoclinic polymorph in the space group C2/c [Becker et al. (2016[Becker, L., Reiss, F., Altenburger, K., Spannenberg, A., Arndt, P., Jiao, H. & Rosenthal, U. (2016). Chem. Eur. J. In the press. doi: 10.1002/chem.201601337.]). Chem. Eur. J. In the press], the thiadiazole ring is planar with an r.m.s. deviation of 0.004 Å. The five-membered ring is tilted with respect to the two pyridyl substituents by 23.16 (7) and 49.47 (9)°. In the crystal, molecules are linked by a weak non-bonding Br⋯N interaction [3.056 (3) Å]. Furthermore, a column of molecules is established along the b axis by π–π stacking interactions between the pyridine rings [centroid–centroid distances = 3.7014 (16) and 3.5934 (15) Å]. Additionally, a short intermolecular Br⋯Br contact [3.3791 (6) Å] and Br⋯π-aryl contacts [3.6815 (11)–3.7659 (12) Å] towards the thiadiazole and pyridine rings are found.