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- ItemSynthesis and molecular structures of the lowest melting odd- and even-numbered a,b-unsaturated carboxylic acids—(E)-hept-2-enoic acid and (E)-oct-2-enoic acid(Basel : MDPI, 2016) Sonneck, Marcel; Spannenberg, Anke; Wohlrab, Sebastian; Peppel, TimThe molecular structures of the two lowest melting odd- and even-numbered α,β-unsaturated carboxylic acids—(E)-hept-2-enoic acid (C7) and (E)-oct-2-enoic acid (C8)—are herein reported. The title compounds were crystallized by slow evaporation of ethanolic solutions at −30 °C. C7 crystallizes in the triclinic space group P1¯ with two molecules in the unit cell and C8 in the monoclinic space group C2/c with eight molecules in the unit cell. The unit cell parameters for C7 are: a = 5.3049(2) Å, b = 6.6322(3) Å, c = 11.1428(5) Å, α = 103.972(3)°, β = 97.542(3)°, γ = 90.104(3)°, and V = 376.92(3) Å3 (T = 150(2) K). The unit cell parameters for C8 are: a = 19.032(10) Å, b = 9.368(5) Å, c = 11.520(6) Å, β = 123.033(11)°, and V = 1721.80(16) Å3 (T = 200(2) K).
- 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.