Chemie

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1,1,2,2-Tetra-phenyl-15-diphosphane 1-sulfide
(Chester : International Union of Crystallography, 2009) Aluri, B.R.; Peitz, S.; Wöhl, A.; Peulecke, N.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.
In the title mol-ecule, C24H20P2S, the P - P bond length is 2.2263 (5) Å. The two phenyl rings attached to the three- and five-coordinated P atoms, respectively, form dihedral angles of 56.22 (5) and 71.74 (5)°.
1,1-Bis(diphenylphosphoryl)hydrazine
(Chester : International Union of Crystallography, 2018) Höhne, Martha; Aluri, Bhaskar R.; Spannenberg, Anke; Müller, Bernd H.; Peulecke, Normen; Rosenthal, Uwe
The 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).
(+)-{1,2-Bis[(2R,5R)-2,5-diethyl-phospho-lan-1-yl]ethane- κ2 P,P′}(≠4-cyclo-octa-1,5-diene)rhodium(I) tetra-fluoridoborate
(Chester : International Union of Crystallography, 2010) Schulz, S.; Fischer, C.; Drexler, H.-J.; Heller, D.
The title compound, [Rh(C8H12)(C18H 36P2)]BF4, exhibits a rhodium(I) complex cation with a bidentate bis-phosphine ligand and a bidentate 2, 2-coordinated cyclo-octa-1,5-diene ligand. The ligands form a slightly distorted square-planar coordination environment for the Rh(I) atom. An intra-molecular P-Rh-P bite angle of 83.91 (2)° is observed. The dihedral angle between the P - Rh - P and the X - Rh - X planes (X is the centroid of a double bond) is 14.0 (1)°. The BF4 anion is disordered over two positions in a 0.515 (7):0.485 (7) ratio.
(+)-{1,2-Bis[(2R,5R)-2,5-dimethyl-phospho-lan-1-yl]ethane- κ2 P,P′}(η4-cyclo-octa-1,5-diene) rhodium(I) tetra-fluorido-borate
(Chester : International Union of Crystallography, 2010) Schulz, S.; Drexler, H.-J.; Heller, D.
The title compound, [Rh(C8H12)(C14H 28P2)]BF4, exhibits a rhodium(I) complex cation with a bidentate bis-phosphine ligand and a bidentate η2, η2-coordinated cyclo-octa-1,5-diene. Together the ligands create a slightly distorted square-planar cordination environment for the Rh(I) atom. There are three mol-ecules in the asymmetric unit and intra-molecular P - Rh - P bite angles of 82.78 (5), 82.97 (6) and 83.09 (5)° are observed. The dihedral angles between the P - Rh - P and the X - Rh - X planes (X is the centroid of a double bond) are 14.7 (1), 14.8 (1) and 15.3 (1)°. The structure exhibits disorder of one cyclo-octa-diene ligand as well as one BF4 anion.
1,7,9,10-Tetrasubstituted PMIs Accessible through Decarboxylative Bromination: Synthesis, Characterization, Photophysical Studies, and Hydrogen Evolution Catalysis
(Weinheim : Wiley-VCH, 2020) Costabel, Daniel; Skabeev, Artem; Nabiyan, Afshin; Luo, Yusen; Max, Johannes B.; Rajagopal, Ashwene; Kowalczyk, Daniel; Dietzek, Benjamin; Wächtler, Maria; Görls, Helmar; Ziegenbalg, Dirk; Zagranyarski, Yulian; Streb, Carsten; Schacher, Felix H.; Peneva, Kalina
In this work, we present a new synthetic strategy for fourfold-substituted perylene monoimides via tetrabrominated perylene monoanhydrides. X-ray diffraction analysis unveiled the intramolecular stacking orientation between the substituents and semicircular packing behavior. We observed the remarkable influence of the substituent on the longevity and nature of the excited state upon visible light excitation. In the presence of poly(dehydroalanine)-graft-poly(ethylene glycol) graft copolymers as solubilizing template, the chromophores are capable of sensitizing [Mo3S13]2− clusters in aqueous solution for stable visible light driven hydrogen evolution over three days. © 2020 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH
1-Benzyl-3-methylimidazolium bromide
(Chester : IUCr, 2020) Peppel, Tim; Wulf, Christoph; Spannenberg, Anke
[no abstract available]
1-Butyl-3-methylimidazolium tribromido(triphenylphosphane-κP)nickelate(II) butan-1-ol hemisolvate
(Chester : IUCr, 2021) Peppel, T.; Köckerling, M.
The solvated title salt, (C8H15N2)[NiBr3(P(C6H5)3)]·0.5C4H10O, was obtained in the form of single crystals directly from the reaction mixture. The molecular structure consists of separated 1-butyl-3-methylimidazolium cations, tribromido(triphenylphosphane)nickelate(II) anions and half a solvent molecule of 1-butanol, all connected via multiple hydrogen contacts to form a three-dimensional network. The co-crystallized 1-butanol molecule is disordered and adopts two orientations. The central C—C bonds of both orientations are located on an inversion centre (Wyckoff site 2b of space group P21/n). Thereby, each orientation has again two orientations with the OH group being located either on one or the other side of the C4 alkyl chain. The dried solvent-free compound exhibits a relatively low melting point (m.p. = 412 K).
[1-Dimethylsilyl-2-phenyl-3-(η5-tetramethylcyclopentadienyl) prop-1-en-1-ylκC1](n5-pentamethylcyclopentadienyl)- titanium(III)
(Chester : International Union of Crystallography, 2009) Lamač, M.; Spannenberg, A.; Arndt, P.; Rosenthal, U.
The title compound, [Ti(C10H15)(C20H 26Si)], was obtained from the reaction of [Ti{5: 1-C5Me4(CH2)}(5-C 5Me5)] with the alkynylsilane PhC2SiMe 2H. The complex crystallizes with two independent mol-ecules in the asymmetric unit, which differ in the conformation of the propenyl unit, resulting in their having opposite helicity. No inter-molecular inter-actions or inter-actions involving the Si- H bond are present. The observed geometrical parameters are unexceptional compared to known structures of the same type.
1-Diphenylphosphanyl-2-(diphenylphosphoryl)hydrazine
(Chester : IUCr, 2018) Höhne, Martha; Aluri, Bhaskar; Spannenberg, Anke; Müller, Bernd H.; Peulecke, Normen; Rosenthal, Uwe
The title compound, C24H22N2OP2, is an asymmetrically substituted hydrazine derivative bearing a phosphoryl and a phosphanyl substituent. The PNNP backbone has a torsion angle of −131.01 (8)°. In the crystal, molecules form centrosymmetric dimers by intermolecular N—H...O hydrogen bonds, which are further linked into a three-dimensional network by weak C—H...O and C—H...π interactions.
The 1-Megapixel pnCCD detector for the Small Quantum Systems Instrument at the European XFEL: system and operation aspects
(Chester : IUCr, 2021) Kuster, Markus; Ahmed, Karim; Ballak, Kai Erik; Danilevski, Cyril; Ekmedžić, Marko; Fernandes, Bruno; Gessler, Patrick; Hartmann, Robert; Hauf, Steffen; Holl, Peter; Meyer, Michael; Montaño, Jacobo; Münnich, Astrid; Ovcharenko, Yevheniy; Rennhack, Nils; Rüter, Tonn; Rupp, Daniela; Schlosser, Dieter; Setoodehnia, Kiana; Schmitt, Rüdiger; Strüder, Lothar; Tanyag, Rico Mayro P.; Ulmer, Anatoli; Yousef, Hazem
The X-ray free-electron lasers that became available during the last decade, like the European XFEL (EuXFEL), place high demands on their instrumentation. Especially at low photon energies below 1 keV, detectors with high sensitivity, and consequently low noise and high quantum efficiency, are required to enable facility users to fully exploit the scientific potential of the photon source. A 1-Megapixel pnCCD detector with a 1024 × 1024 pixel format has been installed and commissioned for imaging applications at the Nano-Sized Quantum System (NQS) station of the Small Quantum System (SQS) instrument at EuXFEL. The instrument is currently operating in the energy range between 0.5 and 3 keV and the NQS station is designed for investigations of the interaction of intense FEL pulses with clusters, nano-particles and small bio-molecules, by combining photo-ion and photo-electron spectroscopy with coherent diffraction imaging techniques. The core of the imaging detector is a pn-type charge coupled device (pnCCD) with a pixel pitch of 75 µm × 75 µm. Depending on the experimental scenario, the pnCCD enables imaging of single photons thanks to its very low electronic noise of 3 e− and high quantum efficiency. Here an overview on the EuXFEL pnCCD detector and the results from the commissioning and first user operation at the SQS experiment in June 2019 are presented. The detailed descriptions of the detector design and capabilities, its implementation at EuXFEL both mechanically and from the controls side as well as important data correction steps aim to provide useful background for users planning and analyzing experiments at EuXFEL and may serve as a benchmark for comparing and planning future endstations at other FELs.
1-Titanacyclobuta-2,3-diene-an elusive four-membered cyclic allene
(Cambridge : RSC, 2019) Reiß, Fabian; Reiß, Melanie; Bresien, Jonas; Spannenberg, Anke; Jiao, Haijun; Baumann, Wolfgang; Arndt, Perdita; Beweries, Torsten
The synthesis of an unusual 1-metalla-2,3-cyclobutadiene complex [rac-(ebthi)Ti(Me3SiC3SiMe3)] (rac-ebthi = rac-1,2-ethylene-1,1′-bis(η5-tetrahydroindenyl)), a formal metallacyclic analogue of a non-existent four-membered 1,2-cyclobutadiene, is described. By variation of the cyclopentadienyl ligand of the titanocene precursor it was possible to stabilise this highly exotic compound which selectively reacts with ketones and aldehydes to yield enynes by oxygen transfer to titanium. Analysis of the bonding and electronic structure of the metallacycle shows that the complex is best described as an unusual antiferromagnetically coupled biradicaloid system, possessing a formal Ti(iii) centre coordinated with a monoanionic radical ligand. © 2019 The Royal Society of Chemistry.
19F NMR-, ESR-, and vis-NIR-spectroelectrochemical study of the unconventional reduction behaviour of a perfluoroalkylated fullerene: dimerization of the C70(CF3)10− radical anion
(Cambridge : Soc., 2015) Zalibera, Michal; Machata, Peter; Clikeman, Tyler T.; Rosenkranz, Marco; Strauss, Steven H.; Boltalina, Olga V.; Popov, Alexey A.
The most abundant isomer of C70(CF3)10 (70-10-1) is a rare example of a perfluoroalkylated fullerene exhibiting electrochemically irreversible reduction. We show that electrochemical reversibility at the first reduction step is achieved at scan rates higher than 500 V s−1. Applying ESR-, vis-NIR-, and 19F NMR-spectroelectrochemistry, as well as mass spectrometry and DFT calculations, we show that the (70-10-1)− radical monoanion is in equilibrium with a singly-bonded diamagnetic dimeric dianion. This study is the first example of 19F NMR spectroelectrochemistry, which promises to be an important method for the elucidation of redox mechanisms of fluoroorganic compounds. Additionally, we demonstrate the importance of combining different spectroelectrochemical methods and quantitative analysis of the transferred charge and spin numbers in the determination of the redox mechanism.
1H MAS NMR and IR studies on powdered alkali-lime-silica glasses
(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2000) Storek, Werner; Peuker, Christel; Geißler, Heinz
Powdered samples of glasses with the composition 16 R2O ∙ 10 CaO ∙ 74 SiO2 (R = Na, K, Cs) and a concentration of water in glass of about 0.03 mol ∙ l^-1 were studied by solid state 1H MAS NMR (magic angle spinning nuclear magnetic resonance). Three superimposed NMR signals at about 6.3, 12.5 and 15.6 ppm were recorded, which were assigned to three different proton sites involved in weak, strong and very strong hydrogen bonds, respectively. The relative intensity of the NMR signals depends on the type of alkali in the glass. The amount of OH groups with strong and very strong hydrogen bonding increases in relation to the weakly bonded hydroxyl groups upon substitution of Na2O, K2O or Cs2O, respectively. The result is in good agreement with the earlier IR findings for these glasses. Thus, Scholze's interpretation [1 to 3] of the region of the OH stretching vibrations in the IR spectra could be verified firstly by NMR spectroscopy as an independent analytical method.
[2,2-Bis(diphenylphosphanyl)propane κ2P,P0] tetracarbonylchromium(0)dichloromethane monosolvate
(Chester : International Union of Crystallography, 2010) Peulecke, N.; Peitz, S.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.
The title compound, [Cr(C27H26P2)(CO) 4]·CH2Cl2, was obtained by the reaction of Ph2PCMe2PPh2 with Cr(CO)6 in refluxing toluene by substitution of two carbonyl ligands. The CrC 4P2 coordination geometry at the Cr atom is distorted octa-hedral, with a P - Cr - P bite angle of 70.27 (2)°.
2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties
(Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2021) Tka, Najeh; Ayed, Mohamed Adnene Hadj; Braiek, Mourad Ben; Jabli, Mahjoub; Chaaben, Noureddine; Alimi, Kamel; Jopp, Stefan; Langer, Peter
Acridine derivatives have attracted considerable interest in numerous areas owing to their attractive physical and chemical properties. Herein, starting from readily available anthranilic acid, an efficient synthesis of 2,4-bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridine derivatives was accomplished via a one-pot double Sonogashira cross-coupling method. The UV-visible absorption and emission properties of the synthesized molecules have been examined. Additionally, theoretical studies based on density functional theory (DFT/B3LYP/6-31G(d)) were carried out.
2,4-Bis(diphenyl-phosphan-yl)-1,1,2,3,3,4-hexa-phenyl-1,3-diphospha-2, 4-dibora-cyclo-butane tetra-hydro-furan sesqui-solvate
(Chester : International Union of Crystallography, 2012) Peulecke, N.; Müller, B.H.; Spannenberg, A.; Rosenthal, U.
In the title compound, C60H50B2P 4·1.5C4H8O, the diphospha-diborane mol-ecule lies on an inversion centre, whereas the disordered tetra-hydro-furan solvent mol-ecule is in a general position with a partial occupancy of 0.75. The diphosphadiborane mol-ecule consists of an ideal planar four-membered B 2P2 ring with an additional phenyl and a-PPH2 group attached to each B atom.
2,6-Bis[(S)-4-benzyl-4,5-dihydro-1,3-oxazol-2-yl]pyridine
(Chester : International Union of Crystallography, 2011) Möller, K.; Junge, K.; Spannenberg, A.; Beller, M.
The commercially available title compound, C25H 23N3O2, has been known since 1993 [Nesper et al. (1993). Helv. Chim. Acta, 76, 2239-2249], but has not been structurally characterized until now. In the free ligand, the N atoms of both oxazoline rings point in opposite directions. The phenyl rings make dihedral angles of 30.56 (5) and 84.57 (3)° with the pyridine ring and 72.85 (3)° with each other.
{2-[Bis(2,4-di-tert-butylphenoxy)-phosphanyloxy-κP]-3, 5-di-tert-butylphenyl-κC 1}[(1,2,5,6-η)-cycloocta-1,5-diene] rhodium(I) toluene monosolvate
(Chester : International Union of Crystallography, 2012) Selent, D.; Spannenberg, A.; Börner, A.
The reaction of (η 3-allyl)[(1,2,5,6-η)-cycloocta-1,5- diene]rhodium(I) with tris-(2,4-di-tert-butylphenyl)phosphite in toluene produces the title compound, [Rh(C 42H 62O 3P)(C 8H 12)]·C 7H 8, by spontaneous metallation at one of the nonsubstituted phenyl ortho-C atoms of the phosphite molecule. The coordination geometry at the Rh I ion is distorted squareplanar. The toluene solvent molecule is disordered over two different orientations, with site-occupation factors of 0.810 (2) and 0.190 (2).
2-hydroxyethylammonium iodide
(Chester : International Union of Crystallography, 2014) Kohrt, C.; Spannenberg, A.; Werner, T.
In the crystal structure of the title salt, C2H 8NO+·I-, N-H⋯O, N-H⋯I and O-H⋯I hydrogen bonds lead to the formation of layers staggered along the c axis.
2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization
(Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2017) Kinzel, Julia; Sauer, Daniel F.; Bocola, Marco; Arlt, Marcus; Mirzaei Garakani, Tayebeh; Thiel, Andreas; Beckerle, Klaus; Polen, Tino; Okuda, Jun; Schwaneberg, Ulrich
Covering hydrophobic regions with stabilization agents to solubilize purified transmembrane proteins is crucial for their application in aqueous media. The small molecule 2-methyl-2,4-pentanediol (MPD) was used to stabilize the transmembrane protein Ferric hydroxamate uptake protein component A (FhuA) utilized as host for the construction of a rhodium-based biohybrid catalyst. Unlike commonly used detergents such as sodium dodecyl sulfate or polyethylene polyethyleneglycol, MPD does not form micelles in solution. Molecular dynamics simulations revealed the effect and position of stabilizing MPD molecules. The advantage of the amphiphilic MPD over micelle-forming detergents is demonstrated in the polymerization of phenylacetylene, showing a ten-fold increase in yield and increased molecular weights.

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