The Max Planck Institute for Coal Research is an institute located in Mülheim an der Ruhr, Germany specializing in chemical research on coals. It is one of the 80 institutes in the Max Planck Society . Founded in 1912 as the Kaiser Wilhelm Institute for Coal Research in Mülheim an der Ruhr to study the chemistry and uses of coal, it became an independent Max Planck Institute in 1949. Wikipedia.
Andresen C.,Linköping University |
Helander S.,Linköping University |
Lemak A.,University of Toronto |
Lemak A.,Ontario Cancer Institute |
And 13 more authors.
Nucleic Acids Research | Year: 2012
The crucial role of Myc as an oncoprotein and as a key regulator of cell growth makes it essential to understand the molecular basis of Myc function. The N-terminal region of c-Myc coordinates a wealth of protein interactions involved in transformation, differentiation and apoptosis. We have characterized in detail the intrinsically disordered properties of Myc-1-88, where hierarchical phosphorylation of S62 and T58 regulates activation and destruction of the Myc protein. By nuclear magnetic resonance (NMR) chemical shift analysis, relaxation measurements and NOE analysis, we show that although Myc occupies a very heterogeneous conformational space, we find transiently structured regions in residues 22-33 and in the Myc homology box I (MBI; residues 45-65); both these regions are conserved in other members of the Myc family. Binding of Bin1 to Myc-1-88 as assayed by NMR and surface plasmon resonance (SPR) revealed primary binding to the S62 region in a dynamically disordered and multivalent complex, accompanied by population shifts leading to altered intramolecular conformational dynamics. These findings expand the increasingly recognized concept of intrinsically disordered regions mediating transient interactions to Myc, a key transcriptional regulator of major medical importance, and have important implications for further understanding its multifaceted role in gene regulation. © 2012 The Author(s).
Identification and counting of oxygen functionalities and alkyl groups of aromatic analytes in mixtures by positive-mode atmospheric pressure chemical ionization tandem mass spectrometry coupled with high-performance liquid chromatography
Amundson L.M.,Purdue University |
Gallardo V.A.,Purdue University |
Vinueza N.R.,Purdue University |
Owen B.C.,Purdue University |
And 8 more authors.
Energy and Fuels | Year: 2012
A tandem mass spectrometric method using a commercial linear quadrupole ion trap (LQIT) mass spectrometer and another LQIT coupled with a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer is described for the identification and counting of different oxygen-containing functionalities and alkyl groups in unknown aromatic analytes. A total of 64 aromatic model compounds were evaporated and ionized via positive-mode atmospheric pressure chemical ionization (APCI). Ionization of the model compounds primarily results in the formation of protonated molecules, [M + H] +. In some cases, the molecular radical cation, [M] +•, and/or a fragment ion, [M - H] +, are formed instead. Only in one case, no ions were observed near the m/z value of the molecular ion, and the ion with the greatest m/z value is a fragment ion, [M + H - H 2O] +. Once ionized, the ions were subjected to multiple isolation and collision-activated dissociation (CAD) events until no more fragmentation was observed (up to MS 5). In most cases, all functionalities were sequentially cleaved, one or more at a time, by the CAD events. The type of neutral molecule cleaved and the number of times that it was cleaved facilitate the identification and counting of the functionalities. The method was successfully used in concert with high-performance liquid chromatography (HPLC). The HPLC retention times offer further structural information for the analytes. This methodology benefits the chemical, pharmaceutical, and biofuels industries by facilitating the identification of previously unknown compounds directly in complex mixtures, such as crude products of chemical processes, drug metabolites, and lignin degradation products. © 2012 American Chemical Society.
Zheng W.,Fritz Haber Institute of the Max Planck Society |
Cotter T.P.,Fritz Haber Institute of the Max Planck Society |
Kaghazchi P.,University of Ulm |
Jacob T.,University of Ulm |
And 7 more authors.
Journal of the American Chemical Society | Year: 2013
Constant COx-free H2 production from the catalytic decomposition of ammonia could be achieved over a high-surface-area molybdenum carbide catalyst prepared by a temperature-programmed reduction-carburization method. The fresh and used catalyst was characterized by N2 adsorption/desorption, powder X-ray diffraction, scanning and transmission electron microscopy, and electron energy-loss spectroscopy at different stages. Observed deactivation (in the first 15 h) of the high-surface-area carbide during the reaction was ascribed to considerable reduction of the specific surface area due to nitridation of the carbide under the reaction conditions. Theoretical calculations confirm that the N atoms tend to occupy subsurface sites, leading to the formation of nitride under an NH3 atmosphere. The relatively high rate of reaction (30 mmol/((g of cat.) min)) observed for the catalytic decomposition of NH3 is ascribed to highly energetic sites (twin boundaries, stacking faults, steps, and defects) which are observed in both the molybdenum carbide and nitride samples. The prevalence of such sites in the as-synthesized material results in a much higher H2 production rate in comparison with that for previously reported Mo-based catalysts. © 2013 American Chemical Society.
News Article | March 14, 2016
Among the elements, cesium, located in the lower left corner of the periodic table, and fluorine, in the upper right corner, are among the largest electropositive and smallest electronegative elements, respectively. When chemists look at possible ways to get the two elements together, something interesting is bound to happen. And it has. Klaus-Richard Pörschke, David Pollak, and Richard Goddard of the Max Planck Institute for Coal Research have prepared a molecule in which a central cesium atom is coordinated by 16 fluorine atoms—achieving a perfect score for the maximum number of bonds possible and establishing a new precedent for bonding in the process. Pörschke announced the team’s discovery in a Division of Inorganic Chemistry symposium at the American Chemical Society national meeting yesterday in San Diego. Going beyond 12 bonds is rare because of the limited space available around the central atom of a molecule and electrostatic repulsion between the ligands. Chemists have flirted with 16-coordinate compounds for years, reporting isolated 15- and 16-coordinate Th-H molecules and a gas-phase 16-coordinate Co-B species. For Pörschke and coworkers, pairing the large singly charged Cs+ cation with the weakly coordinating [H NB (C F ) ]– anion allowed them to go beyond 12 bonds in a complex for the first time without using hydrogen as a ligand. The team prepared Cs[H NB (C F ) ] by using ultrasound to agitate a solution of [Na(OCH CH ) ][H NB (C F ) ] and CsF in dichloromethane. The researchers concentrated the solution and isolated crystals to study by X-ray crystallography. The poor aqueous solubility of the new compound suggested to the researchers that [H NB (C F ) ]– could be a good scavenger of Cs+ in water, which they demonstrated with a set of experiments. Pörschke says that the anion might therefore be useful to pull 134Cs and 137Cs from nuclear waste solutions, as a treatment for 134Cs and 137Cs radiation poisoning, or to prepare implantable 131Cs and 137Cs seeds for radiation therapy. “Pörschke and coworkers have plumbed the limits of coordination chemistry by a careful matching of cation and anion properties,” commented Warren E. Piers, of the University of Calgary, an expert in coordination chemistry. “In addition to the sheer beauty of the molecule, they demonstrate exciting possibilities for radioactive cesium ion sequestration.”
Crespo-Otero R.,Max Planck Institute for Coal Research |
Mardyukov A.,Ruhr University Bochum |
Sanchez-Garcia E.,Max Planck Institute for Coal Research |
Barbatti M.,Max Planck Institute for Coal Research |
Sander W.,Ruhr University Bochum
ChemPhysChem | Year: 2013
The photochemistry of N-methylformamide (MF) is elucidated by investigating its photodissociation products generated by UV irradiation (248 nm) in an argon matrix (10 K). We find that, starting from trans-MF, prolonged irradiation produces cis-MF, CH3NH2 and CO fragments as major products. Another photoproduct is identified as methylformimidic acid (FIA). Nonadiabatic dynamics simulations starting from both MF conformers revealed that the internal conversion occurs within 1 ps through a C-N dissociation channel. The major product is a weakly bound complex between CH3NH and HCO radicals. This complex owes its existence to the cage effect of the matrix which allows for H-transfer reactions and recombination. By identifying the primary photoisomerization and photodissociation pathways of MF, we gain new insights into the photochemistry of peptide bonds in general, which is a prerequisite for a better understanding of the effect of UV irradiation on living systems. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Kraupner A.,Max Planck Institute of Colloids and Interfaces |
Markus Antonietti,Max Planck Institute of Colloids and Interfaces |
Palkovits R.,Max Planck Institute for Coal Research |
Schlicht K.,Max Planck Institute for Coal Research |
Giordano C.,Max Planck Institute of Colloids and Interfaces
Journal of Materials Chemistry | Year: 2010
Mesoporous Fe3C is synthesised by combining a hard-templating approach with carbothermal reduction. The product shows high crystallinity, a transport pore size of d ≈ 20 nm and high specific surface area (415 m 2 g-1). Its usefulness is exemplified by its catalytic activity and high stability in NH3 decomposition. © 2010 The Royal Society of Chemistry.
Dorresteijn R.,Max Planck Institute for Polymer Research |
Nietzel S.,Max Planck Institute for Polymer Research |
Joe D.,Max Planck Institute for Polymer Research |
Gerkmann Y.,Max Planck Institute for Polymer Research |
And 3 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2014
Micrometer-sized spherical polyurethane supports with a narrow size distribution and adjustable porosity were synthesized via the nonaqueous emulsion polymerization technique. They can be directly used in metallocene-catalyzed olefin polymerization, preventing complex aggregation procedures that are typical for other organic and inorganic supports based on silica or latex particles. The reasonable catalytic activity and study of fragmentation behavior, using various optical techniques, demonstrates the potential applicability of the supports. Copyright © 2013 Wiley Periodicals, Inc.
Reichinger M.,Ruhr University Bochum |
Reichinger M.,Sud Chemie AG |
Schmidt W.,Max Planck Institute for Coal Research |
Narkhede V.V.,Ruhr University Bochum |
And 3 more authors.
Microporous and Mesoporous Materials | Year: 2012
Ordered mesoporous materials (OMMs) of 1-dimensional hexagonal and 3-dimensional cubic symmetry of the pore systems were synthesized via well-established soft templating routes starting from precursor solutions of MFI-type zeolites (Silicalite-1, TS-1). The products were characterized by XRD, nitrogen and argon physisorption, DTG/DTA, IR, UV-vis spectroscopy, XANES, TEM, 119Xe NMR, and determination of the pair distribution function (PDF) in order to elucidate their structure, in particular to prove the presence of microporosity in arrays smaller than the coherence lengths of XRD, i.e. in the pore walls. The mesoporosity of the OMMs was well supported by physisorption studies and by TEM while the regularity of the structure was documented by XRD, which also served to exclude the presence of microporous crystalline grains. Instead, microporosity was detected by adsorption/desorption of water on tetrahedrally coordinated Ti-sites (XANES), by 119Xe NMR, by the comparison of the PDF with those of amorphous and of MFI-type solids, and by sequential decomposition of the structure directing agents for meso and micropore systems. From comparison of XRD and physisorption data and from the TEM micrographs, the thickness of the microporous mesopore walls was concluded to be ≈1.5 nm. Therefore, the failure of Ar physisorption to detect pores of sizes typical of MFI structures was attributed to the small micropore volume and the very short pore extension. The structural integrity of OMMs with 1-dimensional hexagonal pore system could be improved by a hydrothermal post-treatment despite the microporous nature of their pore walls, which resulted in more narrow mesopore size distributions peaking at somewhat larger pore sizes. © 2012 Elsevier Inc. All rights reserved.
Reetz M.T.,Max Planck Institute for Coal Research |
Wu S.,Max Planck Institute for Coal Research |
Zheng H.,Max Planck Institute for Coal Research |
Prasad S.,Max Planck Institute for Coal Research
Pure and Applied Chemistry | Year: 2010
Directed evolution has emerged as a powerful method for engineering essentially any catalytic parameter of enzymes for application in synthetic organic chemistry and biotechnology, including thermostability, substrate scope, and enantioselectivity. Enantioselectivity is especially crucial when applying biocatalysts to synthetic organic chemistry. This contribution focuses on recent methodology developments in laboratory evolution of stereoselective enzymes, hydrolases, and monooxygenases serving as the enzymes. Specifically, iterative saturation mutagenesis (ISM) has been developed as an unusually effective method to evolve enhanced or reversed enantioselectivity, broader substrate scope, and/or higher thermostability of enzymes. © 2010 IUPAC.
PubMed | Max Planck Institute for Coal Research
Type: Journal Article | Journal: Chemphyschem : a European journal of chemical physics and physical chemistry | Year: 2013
The photochemistry of N-methylformamide (MF) is elucidated by investigating its photodissociation products generated by UV irradiation (248 nm) in an argon matrix (10 K). We find that, starting from trans-MF, prolonged irradiation produces cis-MF, CH3NH2 and CO fragments as major products. Another photoproduct is identified as methylformimidic acid (FIA). Nonadiabatic dynamics simulations starting from both MF conformers revealed that the internal conversion occurs within 1 ps through a C-N dissociation channel. The major product is a weakly bound complex between CH3NH and HCO radicals. This complex owes its existence to the cage effect of the matrix which allows for H-transfer reactions and recombination. By identifying the primary photoisomerization and photodissociation pathways of MF, we gain new insights into the photochemistry of peptide bonds in general, which is a prerequisite for a better understanding of the effect of UV irradiation on living systems.