bluuebunny/crossref_metadata_2025 huggingface dataset:
Silaethene, XV [1] Pyrolyse von 1-Methyl-1-vinyl-1-silacyclobutan und 1,1-Divinyl-1-silacyclobutan, Folgereaktionen der Silaethene Me(Vi)Si = CH2 und Vi2Si = CH2 / Silaethenes, XV [1] Pyrolysis of 1-Methyl- 1-vinyl- l -silacyclobutane and 1,1-Divinyl- l -silacyclobutane – Follow-up Reactions of the Silaethenes Me(Vi)Si=CH2 and Vi2Si= CH2
Authors: Grobe Joseph , Ziemer Harald
Published: March 2015

The pyrolysis of the silacyclobutanes Vi(Me)Si(CH2)3 (VMS) and Vi2Si(CH2)3 (V2S) at 700-800°C and 10-1-l0-2 mbar leads to the intermediates Vi(Me)Si=CH2 and Vi2Si=CH2, which undergo isomerisation to siliranes followed by cleavage to give allene and the corresponding silylenes Me(H)Si: and Vi(H)Si: respectively. Copyrolyses of these silacyclobutanes with dienes (2,3-dimethyl-1,3-butadiene or isoprene) yield silacyclopentene derivatives (4, 14 and 20). The formation of these products supports the proposed mechanism. The simultaneous existence of silaethenes and silylenes in the gas phase is proven by the presence of the disilacyclobutanes 13 and 17, respectively, in the reaction mixtures. Using isoprene as the quenching reagent for Vi(Me)Si=CH2 the two isomeric silacyclohexenes 15 and 16 are formed in low yield, in addition to almost equal amounts of 13 and 14 (eq. (6)).
Eine unerwartet stabile Sulfensäure: 4,6-Dimethoxy-1,3,5-triazin-2-sulfensäure; Synthese, Eigenschaften, Molekül- und Kristallstruktur / Unexpectedly Stable Sulfenic Acid: 4,6-Dimethoxy-1,3,5-triazine-2-sulfenic Acid; Synthesis, Properties, Molecular and Crystal Structure
Authors: Tripolt Robert , Belaj Ferdinand , Nachbaur Edgar
Published: March 2015

4,6-Dimethoxy-1,3,5-triazine-2-sulfenic acid (1) was prepared by the reaction of 4,6-dimethoxy-1,3,5-triazine-2(1H)-thion (3) with 2-benzenesulfonyl-3-(p-nitrophenyl)-oxaziridine (2) in THF solution and isolated as a stable crystalline solid. The new compound was characterized by analytical and spectroscopic data (IR, 1H and 13C NMR, UV, MS) supported by MNDO-PM 3 calculations. UV spectrometry was used for exact determination of the ionization constant of 1(pKa = 5.86 ± 0.02 at 20°C). According to 13C NMR data and X-ray analysis the sulfenic acid 1 adopts the sulfenyl structure (R—SOH) in the condensed phase.

Crystal data of 1 (90 K): a = 8.418(3), b = 21.289(6), c = 4.411(1) Å, Z = 4, P 21212, R = 0.0304, Rw = 0.0354 for 4105 unique reflections and 122 parameters. In the crystal, the molecules form dimers by two strong intermolecular O—H ••• N hydrogen bonds. The 6-membered ring shows alternating C—N bond lengths and is almost planar. The experimental electron deformation density (EDD) decreases in the order C—N > C—O ≈ C—S > S—O and is described in detail for the vicinity of the S atom.
Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXX 1-Methoxy-2-methyl-3-aryl-2 H-isoindole: Generierung - Charakterisierung - Isolierung / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXX 1-Methoxy-2-methyl-3-aryl-2 H-isoindoles: Generation — Characterization — Isolation
Authors: Clemens Andrea , Kreher Richard P.
Published: March 2015

1-Methoxy-2-methyl-3-aryl-2 H-isoindoles are accessible via an efficient and economical manner starting from 3-aryl-isoindoline-1-ones; the four step synthesis makes use of the ambivalent reactivity of the cyclic carbonamide group. The regiospecific O-methylation and NH-deprotonation is consecuted by the regiospecific N-methylation of the 3-methoxy-1-aryl-1H-isoindoles and the chemoselective CH-deprotonation. The electronic stabilization of these o-quinonoid hetarenes by an aryl group in 3-position is essential for isolation.
Electroreduction of Organic Compounds, 23 [1].
Preparation of the Highly Strained 1′,3′-Dichlorodispiro[cyclopropane-1,2′-bicyclo[ 1.1.0lbutane-4′,1″-cyclopropane][2]
Authors: Strelow Thomas , Voss Jürgen , Baum Werner
Published: March 2015

The preparation of the title compound 4 by electrochemical reduction of 4,4,8,8-tetrachloro-dispiro[2.1.2.1]octane 3 is described. The geometry of the compounds is discussed in terms of quantum chemical calculations and spectroscopic results.
Thermochrome Furofurane, III: Synthese von Bis-chinonmethiden der Anthracenreihe / Thermochromic Furofuranes, III: Synthesis of Bis-quinonemethides with Anthracene Skeleton
Authors: Laatsch Hartmut , Schmidt Andreas Johann
Published: March 2015

Two dimeric bismethides (10 a, 10 b) with anthracene skeleton are obtained by thermolysis of spiroquinole ethers 8 a and 8b. Both methides represent the thermodynamically stable form in the 9 a/10 a system and yield only traces of the photoreactive furanes 9a and 9 b, resp., on heating.
Notizen: The Chemical Evolution of a Nitrogenase Model, XXII. Reduction of Acetylene with Catalysts Derived from Molybdate, Homocitric Acid and N-Methylimidazole and a Proposal Concerning the Active Site of Functional Azotobacter Nitrogenases
Authors: Schrauzer Gerhard N. , Doemeny Paul A. , Palmer John G.
Published: March 2015

Based on model experiments it is suggested that the reduction of substrates by nitrogenase occurs at a mononuclear site containing molybdenum, homocitrate and the imidazole component of his-442 of the apoenzyme, generated from the FeMo-co by a reversible dissociation of the Fe7S8 unit from the MoFe7S8 cluster in a redox-linked process.
Notizen: On the Synthesis of D-Homoandrostanes
Authors: Pelecanou M. , Nicolaropoulos S.
Published: March 2015

The D-ring expansion of 3 β-hydroxy-5 α-androstan-17-one (epiandrosterone) by the cyanogen azide ring-expansion reaction is described. Epiandrosterone was first converted to 17-methylene-3 β-ydroxy-5 α-androstane by a modification of the Wittig reaction employing methylsulfinyl carbanion-dimethyl sulfoxide. Treatment of the 17-methyleno derivative with cyanogen azide followed by hydrolysis led to 3 β-hydroxy-D-homo-5 α-androstan-17 a-one with migrational selectivity.
Das Methylviologen-Radikalkation. Synthese, Kristallstruktur und ab initio-Rechnungen von N,N′-Dimethyl-4,4′ -bipyridinium-chlorid-dihydrat / The Methylviologen Radical Cation. Synthesis, Crystal Structure and ab initio Calculations of N,N′ -Dimethyl-4,4′ -bipyridinium Chloride Dihydrate
Authors: Wolkers Hans , Stegmann Ralf , Frenking Gernot , Dehnicke Kurt , Fenske Dieter , Baum Gerhard
Published: March 2015

The title compound has been prepared by the reduction of N,N′-dimethyl-4,4′-bipyridinium dichloride with dilithium tritelluride in dimethylformamide solution. It forms deep blue crystal needles, which were characterized by a crystal structure determination. Space group Pna 21,Z = 8,3450 observed unique reflections, R = 0.045. Lattice dimensions at -70°C: a =1707.6(8), b = 2323.9(11), c = 664.6(3) pm. The N,N′-dimethyl-4,4′-bipyridinium radical cations are planar and form ion pairs in the lattice. The chloride ions together with the water molecules form an infinite network of hydrogen bridges along the crystallographic a-axis. The structural parameters of the radical cation are in excellent agreement with ab initio calculations.
Does OF2 Form Stable Transition Metal Complexes?. A Density Functional Investigation of the System (OC)5Cr/OF2
Authors: Jacobsen Heiko , Kraatz Heinz-Bernhard , Ziegler Tom , Boorman Philip Michael
Published: March 2015

Density Functional Theory (DFT) within the Local Density Approximation (LDA) was employed to calculate the reaction of OF2 with the metal fragment Cr(CO)5. It is demonstrated that OF2 does not show simple ligand behavior but reacts with the transition metal fragment under oxidative addition, leading to a chromium oxo-complex and transforming two cis CO into fluoroformyl ligands. We calculated this reaction to proceed without any major activation barrier and to be exothermic by about 100 kcal/mol. A possible mechanism for this reaction is discussed
Synthesen und Strukturen von 2,5-Bis(2-arylvinyl)-1,4-benzochinonen und deren photochemisches Verhalten im Kristall / Syntheses and Crystal Structures of 2,5-Bis(2-arylvinyl)-1,4-benzoquinones and their Photochemical Reactivity in the Crystalline State
Authors: Irngartinger Hermann , Lichtenthäler Jochen , Fenske Dieter , Baum Gerhard
Published: March 2015

The 2,5-bis(2-arylvinyl)-1,4-benzoquinones 1a-1e are formed from hydrolysis of their corresponding ketals 5 which are generated by anodic oxidation of the corresponding 1,4-dimethoxybenzene derivatives 4. The crystal structures of the quinone compounds 1a, 1d and 1e have been determined by X-ray analyses. The bond lengths of the quinone system are influenced by polar resonance structures. An α-type packing mode is observed for the three crystal structures of compounds 1. The vinylic double bonds have short intermolecular distances (1a: 4.417(5), 1d: 3.653(2), 1e: 4.224(5) Å). Only the crystals of 1d with the shortest contacts are photoreactive
Circular Dichroism Study on Fully Bioactive CCK-Peptides of Increasing Chain Length
Authors: Moroder Luis , Romano Roberta , Weyher Elisabeth , Svoboda Michal , Christophe Jean
Published: March 2015

A CD conformational analysis has been performed on CCK-peptides elongated at the N-terminus in sequence mode beyond the naturally occurring CCK-8 up to the pentadecapeptide sequence. By extending N-terminally the CCK-8 sequence an intramolecular salt bridge between the tyrosine-O-sulfate and the arginine guanido function is allowed to be established. However, this intramolecular electrostatic interaction was not found to affect the bioactivities of the CCK-peptides indicating that induction of such salt bridge at the level of the ligand molecule does not prevent a similar interaction at receptor level by exchange of the counterion partner. As expected for unconstrained short linear peptides the dichroic properties in aqueous solution were indicative of predominantly random coil structure. Conversely, in aqueous TFE the CD spectra were consistent with the presence of γ-type turns similarly to what has been observed under identical conditions for small size peptides related to the homologuous gastrin hormone. In surfactant solutions the CCK-peptides were found to assume β-type structures by inserting at least the C-terminal portion of the bioactive core into more hydrophobic compartments of the surfactant micelles, whereas the hydrophilic charged N-termini of the CCK-pep-tides of increasing chain length are exposed to the water phase in random coil structures as suggested by the CD spectra. This contrasts previous findings related to the homologuous gastrin peptides, where identical CD spectra were recorded in aqueous TFE and in presence of micelles. This observation strongly suggests that gastrin and CCK related peptides exhibit distinct conformational preferences, despite their high degree of sequence homology, and fully agrees with the ability of CCK to interact specifically with different receptors
Bor-stabilisierte Carbene, III [3 + 2]-Cycloadditionen an Borio-Nitrilylide / Boron-Stabilized Carbenes, III [3 + 2]-Cycloadditions to Borio Nitrile Ylides
Authors: Fehlhammer Wolf Peter , Hoffmeister Hans , Eckert Uwe , Robl Christian
Published: March 2015

The borio nitrile ylides Li[Ph3B—C =N—CH—R] (R = CO2Et, Tos) react with various dipolarophiles regio- and site-specifically to give boron complexes of carbenoid five-membered heterocycles which have been alkylated in order to accomplish their isolation. Thus, isocyanates and isothiocyanates/trialkyloxonium salts give rise to the imidazoline-2-ylidene complexes 2-5, CS2/Et3O+ to the thiazoline-2-ylidene complex 6 and acetone/Et3O+ to the oxazoline-2-ylidene complexes 7a,b. Aryldiazonium ions are added regiospecifically in the “wrong” orientation that leads to mesoionic 1,2,4-triazolium-3-ato-triphenylborate complexes (11a— e). The spectroscopic properties of the new complexes are discussed. Of (1-phenyl-4 H- 5-carbethoxy-triazolium-3-ato)triphenylborate (11a) an X-ray structure analysis has been carried out.
Metallkomplexe mit biologisch wichtigen Liganden, LXVI [1]. Rhodium(III)-, Iridium(III)-, Palladium(II)-, Platin(II)- und Gold(I)-Komplexe von N-(2,3,4,6-Tetra-O-acety-β-ᴅ-glucopyranosyl)-thiocarbamatestern und β-ᴅ-Glucopyranosylthioharnstoff / Metal Complexes of Biologically Important Ligands, LXVI [1]. Rhodium(III), Iridium(III), Palladium(II), Platinum(II), Gold(I) Complexes of N-(2,3,4,6-Tetra-O-acetyl-β-ᴅ-glucopyranosyl)-thiocarbamate Esters and β-ᴅ-Glucopyranosylthiourea
Authors: Pill Thomas , Beck Wolfgang
Published: March 2015

From N-(2,3,4,6-tetra-O-acetyl-β-ᴅ-glucopyranosyl)-thiocarbamate esters (L1) the complexes (η5-C5Me5)(Cl2)M(L1) (M = Rh, Ir),

, trans-(n-Bu3P)(Cl)2M(L1) (M = Pd, Pt), trans-Cl2Pt(L1)2, [(Ph3P)2(Cl)Pt(L1)]+, Cl2Pt(μ-L1)PtCl2 and ClAuL1 have been obtained. β-ᴅ-glucopyranosylthiourea (L2) forms the complexes (η5-C5Me5)(Cl)2M(L2) (M = Rh, Ir), (Cl)Me2NCH2C6H4)Pd(L2), (Et3P)Cl2Pd(L2) and Cl2M(L2)2(M = Pd, Pt).
Halbleiter-Komposite aus [(Me3Sn)3FexCo1-x(CN)6]-Aggregaten (0 < x ≤ 1) und Polypyrrol / Semiconducting Composites Involving [(Me3Sn)3FexCo1-x(CN)6]-Assemblies and Polypyrrole
Authors: Brandt Peter , Illgen Uta , Fischer R. Dieter , Martinez Enrique Sanchez , Calleja Ricardo Diaz
Published: March 2015

Pyrrole has been incorporated into the channel-like cavities of polymers of the type: [(Me3Sn)3FeIII
xCoIII
1-x(CN)6] with 0 < x ≤ 1. The resulting black composites involving polypyrrole (Ppy) and Fe(II) display electrical conductivities σ between ca. 10-5 and 10-1 S · cm-1. Usually, composites prepared in the presence of small amounts of H2O exceed those in conductivity resulting under strictly anhydrous conditions owing to notably lower thermal activation energies (0.04 to 0.08 eV). An oxidative polymerization mechanism differing from that assumed for “classical” modes of Ppy generation is likely, since the N(pyrrole)/Fe(II) ratio turns always out to be ≥ 1. Exposure of a composite with x = 1 to an atmosphere of NH3 causes a decrease of σ from 1.5 · .10-1 to 2.7 · .10-6 S · cm-1; this NH3 uptake, and the concomitant change of σ, appear to be partially reversible. 1-Methylpyrrole, 2,5-dimethylpyrrole and aniline are oxidized by, and incorporated into, the organotin polymer, too, but the resulting σ-values do not exceed ∼10-9 S · cm-1.
Diphenylphosphin-substituiertes, chirales Polyepichlorhydrin, ein Träger für die heterogene, asymmetrische Katalyse / Diphenylphosphine-Substituted, Chiral Polyepichlorohydrin, a Support for the Heterogeneous, Asymmetric Catalysis
Authors: Fritz H. P. , Blümel J. , Dengler D.
Published: March 2015

Chiral polyepichlorohydrin was obtained as a crystalline, optically active powder by coordinative polymerization of S(+)-epichlorohydrin. Subsequent reaction with lithium diphenylphosphide in THF resulted in substitution of about 90% of the chlorine atoms by the P(C6H5)2 group to give an insoluble polymer, which was characterized by elemental analysis, 31P CP MAS NMR, and IR spectroscopy. On addition of solutions of bis(1.5-cyclooctadiene)-rhodium tetrafluoroborate to the polymer “heterogenization” of the complex occurred. The reason for the as yet short operational life time during the hydrogenation of α-acetamido cinnamic acid is the leaching of the metal complex moiety. The rhodium atom is coordinated to only one phosphorus atom of the polymer in the side group and rather weakly to one oxygen atom of the polymer chain.
Thieno[2,3-b]thiopheno[3,2-c; 4,5-c']-bis(1,2-dithiole)-3,6-d¡thione – An Octamer of Carbon Sulfide
Authors: Gompper Rudolf , Knieler Roland , Polborn Kurt
Published: March 2015

The title compound, an octamer C8S8 of carbon sulfide, is obtained by reacting diethyl dihydroxythieno[2,3-b]thiophenedicarboxylate with the Lawesson reagent in the presence of sulfur. The crystal structure shows three-dimensional sulfur-sulfur interactions.
Synthese und Kristallstrukturen der Palladium(II)-Komplexe cis- und trans-PdCl2[P(OSiMe3)3]2, {PdCl[PO(OSiMe3)2][P(OSiMe3)3]2} und (NMe2H2)2{Pd2Cl4[P4O5(OSiMe3)4]} / Synthesis und Crystal Structures of the Palladium(II) Complexes cis- and trans-PdCl2[P(OSiMe3)3]2, {PdCl[PO(OSiMe3)2][P(OSiMe3)3]2} and (NMe2H2)2{Pd2Cl4[P4O5(OSiMe3)4]}
Authors: Gebauer Thorsten , Frenzen Gerlinde , Dehnicke Kurt
Published: March 2015

The molecular complex PdCl2[P(OSiMe3)3]2 was obtained both as cis- (la) and trans- (lb) isomer from palladium(II) chloride with the equivalent amount of tris(trimethylsilyl)phosphite in a THF suspension at room temperature. With excess P(OSiMe3)3 the complex {PdCI[PO(OSiMe3)2][P(OSiMe3)3]2} (2) is formed with elimination of trimethylchlorosilane. By partial hydrolysis the anionic binuclear palladium complex

(NMe2H2)2{Pd2Cl4[P4O5(OSiMe3)4]} (3) is generated from palladium(II) chloride and excess P(OSiMe3)3 in THF in the presence of dimethylamine. All complexes form colourless, moisture-sensitive crystals, which were characterized by X-ray structure determinations.

1a: Space group C2/c, Z = 4,2973 observed unique reflections, R = 0.044. Lattice dimensions at —80°C: a =1052.9(2), b =1675.3(5), c = 2240.1(7) pm, β = 99.88(2)°. The compound has a molecular structure with cis-arrangement of the P(OSiMe3)3 groups with Pd—P bond lengths of 222.9 pm.

1b: Space group P1̄, Z = 1, 3796 observed unique reflections, R = 0.053. Lattice dimensions at-70°C: a = 959.5(2), b = 998.3(2), c =1162.6(2) pm, α=86.99(3)°, β = 81.63(3)°, γ = 62.91(3)°. The compound has a molecular structure with trans-arrangement of the P(OSiMe3)3 groups with Pd—P bond lengths of 230.4 pm.

2: Space group P212121, Z = 4,4444 observed unique reflections, R = 0.055. Lattice dimensions at —70°C: a =1050.0(2), b = 2090.5(3), c = 2357.8(6) pm. The complex has a molecular structure with trans-arrangement of the P(OSiMe3)3 groups with Pd — P bond lengths of 233.6 and 232.1 pm. The Pd—P bond length of the [PO(OSiMe3)2]- ligand is 224.8 pm.

3: Space group P1̄, Z = 2,4762 observed unique reflections, R = 0.071. Lattice dimensions at —80°C: a = 1169.3(6), b = 1299.6(6), c = 1641.7(12) pm, α = 69.19(4)°, β = 87.37(5)°, γ = 80.01(4)°. In the dimeric anion {Pd2Cl4[P4O5(OSiMe3)4]}2- the two cis-PdCl2 units are bridged by the four phosphorus atoms of the [P4O5(OSiMe3
3)4]2- ligand with average Pd— P bond lengths of 221.5 pm.
Übergangsmetallkomplexe mit Schwefelliganden, XCIX. Bildung und Struktur von [Fe(′S4′)]4. Eine bemerkenswerte Tetramerisierung homochiraler[Fe(′S4′)]-Komplexfragmente (′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethan(2-)) / Transition Metal Complexes with Sulfur Ligands, XCIX. Formation and Structure of [Fe(′S4′)]4. A Remarkable Tetramerization of Homochiral [Fe(′S4′)] Complex Fragments (′S4′2-= 1,2-Bis(2-mercaptophenylthio)ethane(2–))
Authors: Sellmann Dieter , Friedrich Helge , Knoch Falk
Published: March 2015

In MeOH/THF solution, Fe(II) ions and the tetradentate thioether-thiolate ′S4′2-([1,2-Bis(2-mercaptophenylthio)ethane(2-)]) slowly form the tetrameric [Fe(′S4′)]4 1. The crystal structure of 1 · THF • 2 MeOH was determined by X-ray structure analysis. Chiral 1 crystallizes as a pair of enantiomers each of which consist of four homochiral [Fe(′S4′)] fragments bridged via μ2- and µ3-S(thiolato) donors; stereochemical aspects of the enantiospecific tetramerization of [Fe(′S4′)] fragments are discussed. In strong polar solvents such as dimethylformamide, dissociation of [Fe(′S4′)]4 into [Fe(′S4′)]2 fragments is indicated by the formation of [Fe(CO)(′S4′)]2 upon reaction with CO.
Zwitterionische Bis[vic-arendiolato(2 –)] [(morpholinio)alkyl]silicate: Synthese sowie strukturelle Charakterisierung in Lösung und im Kristall / Zwitterionic Bis[vic-arenediolato(2 –)] [(morpholinio)alkyl]silicates: Synthesis and Structural Characterization in Solution and in the Crystal
Authors: Sperlich Jörg , Becht Joachim , Mühleisen Mathias , Wagner Stephan A. , Mattern Günter , Tacke Reinhold
Published: March 2015

The zwitterionic A5-spirosilicates bis[1,2-benzenediolato(2–)][(morpholinio)methyl]silicate (1), bis[2,3-naphthalenediolato(2–)][(morpholinio)methyl]silicate (2; isolated as 2 • CH3CN), bis[1,2-benzenediolato(2–)][3-(morpholinio)propyl]silicate (3) and bis[2,3-naphthalenediolato(2 –)][3-(morpholinio)propyl]silicate (4; isolated as 4·1/2CH3CN) have been synthesized by various methods including Si – C bond cleavage reactions. The crystal structures of 2 • CH3CN and 4 · 1/2 CH3CN have been determined. 1,2 • CH3CN, 3 and 4 · 1/2 CH3CN have also been characterized by solution-state (1H, 13C, 29Si) and solid-state NMR spectroscopy (29Si CP/MAS). The pentacoordinate silicon atoms of the zwitterions 1-4 are surrounded by four oxygen atoms and one carbon atom. In the crystal, the coordination polyhedra around the silicon atoms of 2 • CH3CN (two crystallographically independent zwitterions and two crystallographically independent acetonitrile molecules) can be described as nearly ideal trigonal bipyramids, with the carbon atoms occupying equatorial sites. The crystal structure of 2 • CH3CN is considerably influenced by intermolecular N – H···N hydrogen bonds between the zwitterions and the acetonitrile molecules. The coordination polyhedron observed for the silicon atom in the crystal of 4 · 1/2 CH3CN can be described as a distorted square pyramid, with the carbon atom in the apical position. The crystal structure of 4 · 1/2 CH3CN is considerably governed by intermolecular N –H···O hydrogen bonds between the zwitterions which form infinite chains in the crystal. The 29Si chemical shifts (δ = – 75,5 to – 85,8) observed for 1,2 • CH3CN, 3 and 4 · 1/2 CH3CN in solution ([D6]DMSO) and in the crystal are typical of pentacoordinate silicon of the type SiO4C. For all compounds very similar 29Si chemical shifts have been observed for the solution and solid state [⊿(δ29Si) ≤ 0,9] indicating that the zwitterions 1-4 do also exist in solution.
Transition Metal Complexes of Oxamide Oxime, 1. Synthesis and X-Ray Crystal Structure of Tris(oxamide oxime-N1,N1′)cobalt(III) Triiodide [Co(H2oxao)3]I3
Authors: Mégnamisi-Bélombé Michel , Jokwi Irene , Ngameni Emmanuel , Roux Robert , Nuber Bernhard
Published: March 2015

Tris(oxamide oxime-N1,N1′)cobalt(III) triiodide, [Co(H2oxao)3]I3, has been synthesized, and its structure determined by single crystal X-ray diffraction at room temperature. The trigonal structure (rhombohedral space group R 3̄ c) was refined by full matrix least-squares to a final R (Rw) of 4.1 (3.5)% for 51 parameters and 911 observed independent reflections. The structure consists exclusively of quasi-octahedral chiral cobaloxime cations, [Co(H2oxao)3]3+, and iodide anions. This structure is isotypic to that of the homologous Ni-based salt analyzed previously in which, as a matter of specific difference, one H2O molecule of crystallization per formula unit is present. Moreover, whereas nickel in the latter salt was identified as NiII on the basis of magnetic data, preliminary voltammetric data clearly reveals Com in the present salt.
Darstellung von Mononitropentahydrohexaborat(2-) und Kristallstruktur von M2[B6H5(NO2)], M = K, Cs / Preparation of Mononitropentahydrohexaborate(2—) and Crystal Structure of M2[B6H5(NO2)], M = K, Cs
Authors: Franken A. , Preetz W. , Rath M. , Hesse K.-F.
Published: March 2015

By electrochemical oxidation of [B6H6]2- in the presence of nitrite ions and the base DBU in dichloromethane solution mononitropentahydrohexaborate [B6H5(NO2)]2- ions are formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of the K and Cs salt were determined from single crystal X-ray diffraction analyses. K2[B6H5(NO2)] is monoclinic, space group P21/m with a = 5.953(1), b = 8.059(4), c = 8.906(1) Å, β = 109.553(9)°; Cs2[B6H5(NO2)] is monoclinic, space group P21/a with a = 9.438(6), b = 9.644(7), c = 11.138(9) Å, β = 101.44(9)°. The B6 octahedron is compressed in the direction of the B—NO2 bond by about 5%, with bond lengths between 1.67 and 1.77 A.
Preparation, Properties, and Structure of the Polyphosphides VNi4P16, NbNi4P16, and WNi4P16
Authors: Jeitschko Wolfgang , Wallinda Jörg , Dewalsky Martin V. , Wortmann Ulrich
Published: March 2015

The title compounds were prepared by reacting powders of the binary transition metal alloys with phosphorus in a tin melt. They crystallize with a monoclinic structure of space group C 2/c, which was determined from single-crystal X-ray data; VNi4P16: a = 1956.0(3), b = 565.9(1), c = 1106.6(2) pm, β = 100.99(1)°, R = 0.020 for 1904 structure factors and 97 variable parameters; NbNi4P16: α = 1973.0(3), b = 571.2(3), c = 1117.2(2) pm, β = 100.74(1)°, R = 0.023 for 2431 F-values and 97 variables; WNi4P16: a = 1964.2(3), b = 568.3(2), c = 1109.3(2) pm, β = 101.04(2)°, R = 0.031 for 371 F-values and 43 variables. The T atoms (T = V, Nb, W) have eight Ρ neighbors, which form a slightly distorted square antiprism, and the Ni atoms have approximately octahedral Ρ coordination. The Ρ atoms form novel P8 units, which consist of 6-membered rings with a P2 side chain. Chemical bonding is discussed on the basis of classical twoelectron bonds. A comparison of the interatomic distances suggests that the Fermi level cuts through a band formed by antibonding nickel-phosphorus states. A band structure is proposed, which also rationalizes the metallic conductivity and the Pauli paramagnetism of the compounds.
Hydrophilic Polystyrene-Polyoxyethylene Graft Polymer Beads as Carrier of Antigenic Peptides for in vivo and in vitro Immunization Techniques: Applications to the Non-Catalytic Zinc Loop of HLADH Isozymes and to Histone Fragments
Authors: Zeppezauer Michael , Hoffmann Ralf , Schönberger Arno , Rawer Stephan , Rapp Wolfgang , Bayer Ernst
Published: March 2015

Polystyrene-polyethyleneglycol tentacle polymers (PS–PEG) are a novel class of graft copolymer beads based on a polystyrene matrix grafted with a brush-like layer of polyoxyethylene tentacles [9-12].

Immunogenic materials were obtained by synthesizing on tentacle polymer-bound amino derivatives as a solid support the following haptens: The C-terminal sequence 187—211 KPKAA KPKAA KPKAA KPKAA KPKKA APKKK and the N-terminal sequence 3-31 APAAP AAAPP AEKTP VKKKA AKKPA GA of histone H 1 (calf thymus), as well as the sequences 93-116 of the horse liver alcohol dehydrogenase EE (FTPQC GKCRV CKHPE GNFCL KNDL) and SS (FIPQC GKCSV CKHPE GNLCL KNSL) isozymes (Jörnvall (1970) Eur. J. Biochem. 16, 41-49), respectively. These materials proved to be efficient immunogens both in vivo and in vitro, showing excellent biocompatibility compared to other solid hapten carriers. Tentacle-based immunogens are generally available by standard synthetic procedures either by in situ synthesis of hapten molecules on or by covalent attachment of available antigens or haptens to the beads. Advantageous is the possibility to synthesize the peptide on the tentacle polymer, and to use the solid phase bound peptide directly as hapten. The beads serve as carriers, and no separate splitting off the peptide and binding to another carrier is necessary.
Notizen: Y7I6C3O: Ein Carbidoxid mit kondensierten Y6C-Oktaedern und Y4O-Tetraedern / Y7I6C3O: A Carbide Oxide with Condensed Y6C-Octahedra and Y4O-Tetrahedra
Authors: Mattausch Hansjürgen , Borrmann Horst , Simon Arndt
Published: March 2015

The new compound Y7I6C3O is prepared by reaction of stoichiometric amounts of Y, YI3, Y2O3 and C in closed Ta capsules at 1370 K. Y7I6C3O forms bronze coloured, metallic, air and moisture sensitive crystals. It crystallizes in the space group Pmma (No. 51) with the lattice constants a = 2249.4(4), b = 383.7(1), c = 1079.1(1) pm. Within the crystal structure the C atoms and the O atoms are surrounded by Y atoms octahedrally and tetrahedrally, respectively. The Y6C octahedra and Y4O tetrahedra are condensed to form ondulated layers, which are separated by double layers of I atoms.
Notizen: Ca3[MnN3], ein neues Nitridomanganat(III): Anionen [MnIIIN3]6- mit C2v-Symmetrie / Ca3[MnN3], a New Nitridomanganate(III): Anions [MnIIIN3]6- with C2v-Symmetry
Authors: Tennstedt Andreas , Röhr Caroline , Kniep Rüdiger
Published: March 2015

Ca3[MnN3] (orthorhomb. Cmcm (Nr. 63); a = 842.6(1), b = 1024.7(2), c= 501.4(1) pm; Z=4) was prepared by reaction of mixtures of Li, Ca and Mn (molar ratio 6:1:1) in tantalum crucibles with nitrogen (1 atm) at 900°C. The crystal structure contains distorted trigonal-planar anions [MnN3]6- with C2v-symmetry (Mn—N: 179.4(4) pm and 179.9(5) pm; N—Mn—N: 114.7(1)° and 130.6(2)°). Ca3[MnN3] is an isotype of Ca3[CrN3] and Ca3[VN3].
Notizen: Die Kristallstruktur von KLiTe / The Crystal Structure of KLiTe
Authors: Sabrowsky Horst , Hitzbleck Rolf-Dieter , Vogt Petra
Published: March 2015

The crystal structure of KLiTe described earlier as a dark grey powder compound has been determined by X-ray diffraction of single crystals. Very hygroscopic KLiTe crystallizes in the tetragonal space group P4/nmm (Z = 2) with the cell parameters a = 483.0(1) and c = 770.4(2) pm. The structure was determined from 211 independent reflections by Patterson and Fourier methods (R = 0.013; wR = 0.013).
Notizen: 1,2-Dimethoxyethan-Komplexe von MoNCl3 und WNCl3. Die Kristallstruktur von [MoNCl3 · DME] / 1,2-Dimethoxyethane Complexes of MoNCl3 and WNCl3. The Crystal Structure of [MoNCl3 · DME]
Authors: Rentschler Eva , Dehnicke Kurt
Published: March 2015

The complexes [MoNCl3·DME] and [WNCl3·DME] (DME = 1,2-dimethoxyethane) have been prepared by the reaction of the nitride chlorides MNC13 with equimolar amounts of DME in CH2Cl2 suspensions. They form orangered, moisture sensitive crystals, which are soluble in organic solvents. The molybdenum complex has been characterized by a crystal structure determination. Space group Pbca, Z = 8, structure solution with 1781 observed unique reflections, R = 0.031. Lattice dimensions at –60°C: a = 738.6(1), b = 1182.2(1), c = 2314.1(1) pm. [MoNCl3·DME] forms monomeric complexes with chelating DME molecules and Mo–O bond lengths of 215.4(4) and 247.4(4) pm, the longer one being in trans-position of the nitrido ligand. The MoN bond length of 163.3(5) pm suggests a triple bond.
Notizen: Kristallstruktur von μ-Oxo-bis[oxo-salicylaldehydbenzoylhydrazonato(2 —)]vanadium(V) / Crystal Structure of μ-Oxo-bis[oxo-salicylaldehydbenzoylhydrazonato(2 —)]vanadium(V)
Authors: Sundheim Angelika , Mattes Rainer
Published: March 2015

The dimeric title complex contains a V2O3
4+ unit with a rather small (112.6°) V-O-V angle and exhibits crystallographic C2 symmetry. Each vanadium center is equatorially coordinated by the tridentate doubly deprotonated hydrazone formed from salicylaldehyde and benzoylhydrazine. The coordination sphere is distorted square pyramidal. Crystal data: orthorhombic, space group Pnc2, a = 758.2(2), b = 1454.4(3), c = 1186.1(2) pm, Z = 4, 1137 reflections, 184 parameters, R (Rw) = 0.032 (0.032).
Certified KLST Miniaturized Charpy Specimens for the Indirect Verification of Small-Scale Impact Machines
Authors: Lucon E. , McCowan C. N. , Santoyo R. L. , Splett J. D.
Published: March 2015

Small specimen test techniques are becoming ever more popular as the need increases to characterize mechanical properties by use of the smallest possible amount of material, because of various restrictions on material availability, irradiation, testing space, and other factors. The National Institute of Standards and Technology (NIST) recently qualified reference miniaturized Charpy V-notch (MCVN) specimens for the indirect verification of small-scale impact testing machines (with capacity in the range 15 J to 50 J and impact velocity around 3.8 m/s). The same materials used for NIST standard verification specimens were evaluated at three energy levels (low, high, and super-high). The miniaturized specimen type investigated is denominated KLST (from the German Kleinstprobe, or “small specimen”). In the first phase of the qualification activity, several instrumented impact tests on miniaturized KLST specimens of low, high, and super-high energy were performed and analyzed at NIST. In this part of the study, which was published elsewhere [Lucon, E., “Certified Miniaturized Charpy Specimens for the Indirect Verification of Small-Size Impact Machines,” Mater. Perform. Character., Vol. 2, No. 1, 2013], the variability of MCVN data was compared to that of full-size Charpy data from the same lot of specimens. Additional aspects were also investigated, such as the influence of shear lip symmetry and specimen full or partial fracture on absorbed energy, and the correlation between miniaturized and full-size Charpy data. In the second phase of the qualification activity, certified values of absorbed energy and maximum force were established for each energy level by means of an international round robin, which involved nine highly qualified laboratories. The results of this round robin, and the outcome of the statistical analyses performed in accordance with ASTM E691-13 (ASTM E691-13: Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, ASTM International, West Conshohocken, PA) and ISO 5725-2 [ISO 5725-2, 1994, “Accuracy (Trueness and Precision) of Measurement Methods and Results,” International Organization for Standardization, Geneva, Switzerland], are presented in this paper. Complete details are provided by NIST [Lucon, E., McCowan, C., Santoyo, R., and Splett, J., “Standard Reference Materials—Certification Report for SRM 2216, 2218, 2219: KLST (Miniaturized) Charpy V-Notch Impact Specimens,” NIST Special Publication 260-180, National Institute of Standards and Technology, Gaithersburg, MD, 2013], which accompanies the certified KLST.
Dual Mechanism for Bitter Avoidance inDrosophila
Authors: French Alice Sarah , Sellier Marie-Jeanne , Ali Agha Moutaz , Guigue Alexandra , Chabaud Marie-Ange , Reeb Pablo D. , Mitra Aniruddha , Grau Yves , Soustelle Laurent , Marion-Poll Frédéric
Published: March 2015

In flies and humans, bitter chemicals are known to inhibit sugar detection, but the adaptive role of this inhibition is often overlooked. At best, this inhibition is described as contributing to the rejection of potentially toxic food, but no studies have addressed the relative importance of the direct pathway that involves activating bitter-sensitive cells versus the indirect pathway represented by the inhibition of sugar detection. Using toxins to selectively ablate or inactivate populations of bitter-sensitive cells, we assessed the behavioral responses of flies to sucrose mixed with strychnine (which activates bitter-sensitive cells and inhibits sugar detection) or withl-canavanine (which only activates bitter-sensitive cells). As expected, flies with ablated bitter-sensitive cells failed to detectl-canavanine mixed with sucrose in three different feeding assays (proboscis extension responses, capillary feeding, and two-choice assays). However, such flies were still able to avoid strychnine mixed with sucrose. By means of electrophysiological recordings, we established that bitter molecules differ in their potency to inhibit sucrose detection and that sugar-sensing inhibition affects taste cells on the proboscis and the legs. The optogenetic response of sugar-sensitive cells was not reduced by strychnine, thus suggesting that this inhibition is linked directly to sugar transduction. We postulate that sugar-sensing inhibition represents a mechanism in insects to prevent ingesting harmful substances occurring within mixtures.
Extracellular pH Regulates Excitability of Vomeronasal Sensory Neurons
Authors: Cichy Annika , Ackels Tobias , Tsitoura Chryssanthi , Kahan Anat , Gronloh Nina , Söchtig Melanie , Engelhardt Corinna H. , Ben-Shaul Yoram , Müller Frank , Spehr Jennifer , Spehr Marc
Published: March 2015

The mouse vomeronasal organ (VNO) plays a critical role in semiochemical detection and social communication. Vomeronasal stimuli are typically secreted in various body fluids. Following direct contact with urine deposits or other secretions, a peristaltic vascular pump mediates fluid entry into the recipient's VNO. Therefore, while vomeronasal sensory neurons (VSNs) sample various stimulatory semiochemicals dissolved in the intraluminal mucus, they might also be affected by the general physicochemical properties of the “solvent.” Here, we report cycle stage-correlated variations in urinary pH among female mice. Estrus-specific pH decline is observed exclusively in urine samples from sexually experienced females. Moreover, patch-clamp recordings in acute VNO slices reveal that mouse VSNs reliably detect extracellular acidosis. Acid-evoked responses share the biophysical and pharmacological hallmarks of the hyperpolarization-activated currentIh. Mechanistically, VSN acid sensitivity depends on a pH-induced shift in the voltage-dependence ofIhactivation that causes the opening of HCN channels at rest, thereby increasing VSN excitability. Together, our results identify extracellular acidification as a potent activator of vomeronasalIhand suggest HCN channel-dependent vomeronasal gain control of social chemosignaling. Our data thus reveal a potential mechanistic basis for stimulus pH detection in rodent chemosensory communication.
Converging Structural and Functional Connectivity of Orbitofrontal, Dorsolateral Prefrontal, and Posterior Parietal Cortex in the Human Striatum
Authors: Jarbo Kevin , Verstynen Timothy D.
Published: March 2015

Modification of spatial attention via reinforcement learning (Lee and Shomstein, 2013) requires the integration of reward, attention, and executive processes. Corticostriatal pathways are an ideal neural substrate for this integration because these projections exhibit a globally parallel (Alexander et al., 1986), but locally overlapping (Haber, 2003), topographical organization. Here we explore whether there are unique striatal regions that exhibit convergent anatomical connections from orbitofrontal cortex, dorsolateral prefrontal cortex, and posterior parietal cortex. Deterministic fiber tractography on diffusion spectrum imaging data from neurologically healthy adults (N= 60) was used to map frontostriatal and parietostriatal projections. In general, projections from cortex were organized according to both a medial–lateral and a rostral–caudal gradient along the striatal nuclei. Within rostral aspects of the striatum, we identified two bilateral convergence zones (one in the caudate nucleus and another in the putamen) that consisted of voxels with unique projections from orbitofrontal cortex, dorsolateral prefrontal cortex, and parietal regions. The distributed cortical connectivity of these striatal convergence zones was confirmed with follow-up functional connectivity analysis from resting state fMRI data, in which a high percentage of structurally connected voxels also showed significant functional connectivity. The specificity of this convergent architecture to these regions of the rostral striatum was validated against control analysis of connectivity within the motor putamen. These results delineate a neurologically plausible network of converging corticostriatal projections that may support the integration of reward, executive control, and spatial attention that occurs during spatial reinforcement learning.
Cannabinoid CB1 Receptor Calibrates Excitatory Synaptic Balance in the Mouse Hippocampus
Authors: Monory Krisztina , Polack Martin , Remus Anita , Lutz Beat , Korte Martin
Published: March 2015

The endocannabinoid system negatively regulates the release of various neurotransmitters in an activity-dependent manner, thereby influencing the excitability of neuronal circuits. In the hippocampus, cannabinoid type 1 (CB1) receptor is present on both GABAergic and glutamatergic axon terminals. CB1 receptor-deficient mice were previously shown to have increased hippocampal long-term potentiation (LTP). In this study, we have investigated the consequences of cell-type-specific deletion of the CB1 receptor on the induction of hippocampal LTP and on CA1 pyramidal cell morphology. Deletion of CB1 receptor in GABAergic neurons in GABA-CB1-KO mice leads to a significantly decreased hippocampal LTP compared with WT controls. Concomitantly, CA1 pyramidal neurons have a significantly reduced dendritic branching both on the apical and on the basal dendrites. Moreover, the average spine density on the apical dendrites of CA1 pyramidal neurons is significantly diminished. In contrast, in mice lacking CB1 receptor in glutamatergic cells (Glu-CB1-KO), hippocampal LTP is significantly enhanced and CA1 pyramidal neurons show an increased branching and an increased spine density in the apical dendritic region. Together, these results indicate that the CB1 receptor signaling system both on inhibitory and excitatory neurons controls functional and structural synaptic plasticity of pyramidal neurons in the hippocampal CA1 region to maintain an appropriate homeostatic state upon neuronal activation. Consequently, if the CB1 receptor is lost in either neuronal population, an allostatic shift will occur leading to a long-term dysregulation of neuronal functions.
Dissociable Rate-Dependent Effects of Oral Methylphenidate on Impulsivity and D2/3Receptor Availability in the Striatum
Authors: Caprioli Daniele , Jupp Bianca , Hong Young T. , Sawiak Stephen J. , Ferrari Valentina , Wharton Laura , Williamson David J. , McNabb Carolyn , Berry David , Aigbirhio Franklin I. , Robbins Trevor W. , Fryer Tim D. , Dalley Jeffrey W.
Published: March 2015

We have previously shown that impulsivity in rats is linked to decreased dopamine D2/3receptor availability in the ventral striatum. In the present study, we investigated, using longitudinal positron emission tomography (PET), the effects of orally administered methylphenidate (MPH), a first-line treatment for attention deficit hyperactivity disorder, on D2/3receptor availability in the dorsal and ventral striatum and related these changes to impulsivity. Rats were screened for impulsive behavior on a five-choice serial reaction time task. After a baseline PET scan with the D2/3ligand [18F]fallypride, rats received 6 mg/kg MPH, orally, twice each day for 28 d. Rats were then reassessed for impulsivity and underwent a second [18F]fallypride PET scan. Before MPH treatment, we found that D2/3receptor availability was significantly decreased in the left but not the right ventral striatum of high-impulse (HI) rats compared with low-impulse (LI) rats. MPH treatment increased impulsivity in LI rats, and modulated impulsivity and D2/3receptor availability in the dorsal and ventral striatum of HI rats through inverse relationships with baseline levels of impulsivity and D2/3receptor availability, respectively. However, we found no relationship between the effects of MPH on impulsivity and D2/3receptor availability in any of the striatal subregions investigated. These findings indicate that trait-like impulsivity is associated with decreased D2/3receptor availability in the left ventral striatum, and that stimulant drugs modulate impulsivity and striatal D2/3receptor availability through independent mechanisms.
Drugs that reverse disease transcriptomic signatures are more effective in a mouse model of dyslipidemia
Authors: Wagner Allon , Cohen Noa , Kelder Thomas , Amit Uri , Liebman Elad , Steinberg David M , Radonjic Marijana , Ruppin Eytan
Published: March 2015

High‐throughput omics have proven invaluable in studying human disease, and yet day‐to‐day clinical practice still relies on physiological, non‐omic markers. The metabolic syndrome, for example, is diagnosed and monitored by blood and urine indices such as blood cholesterol levels. Nevertheless, the association between the molecular and the physiological manifestations of the disease, especially in response to treatment, has not been investigated in a systematic manner. To this end, we studied a mouse model of diet‐induced dyslipidemia and atherosclerosis that was subject to various drug treatments relevant to the disease in question. Both physiological data and gene expression data (from the liver and white adipose) were analyzed and compared. We find that treatments that restore gene expression patterns to their norm are associated with the successful restoration of physiological markers to their baselines. This holds in a tissue‐specific manner—treatments that reverse the transcriptomic signatures of the disease in a particular tissue are associated with positive physiological effects in that tissue. Further, treatments that introduce large non‐restorative gene expression alterations are associated with unfavorable physiological outcomes. These results provide a sound basis to in silico methods that rely on omic metrics for drug repurposing and drug discovery by searching for compounds that reverse a disease's omic signatures. Moreover, they highlight the need to develop drugs that restore the global cellular state to its healthy norm rather than rectify particular disease phenotypes.
Cell shape and the microenvironment regulate nuclear translocation of NF‐κB in breast epithelial and tumor cells
Authors: Sero Julia E , Sailem Heba Zuhair , Ardy Rico Chandra , Almuttaqi Hannah , Zhang Tongli , Bakal Chris
Published: March 2015

Although a great deal is known about the signaling events that promote nuclear translocation of NF‐κB, how cellular biophysics and the microenvironment might regulate the dynamics of this pathway is poorly understood. In this study, we used high‐content image analysis and Bayesian network modeling to ask whether cell shape and context features influence NF‐κB activation using the inherent variability present in unperturbed populations of breast tumor and non‐tumor cell lines. Cell–cell contact, cell and nuclear area, and protrusiveness all contributed to variability in NF‐κB localization in the absence and presence of TNFα. Higher levels of nuclear NF‐κB were associated with mesenchymal‐like versus epithelial‐like morphologies, and RhoA‐ROCK‐myosin II signaling was critical for mediating shape‐based differences in NF‐κB localization and oscillations. Thus, mechanical factors such as cell shape and the microenvironment can influence NF‐κB signaling and may in part explain how different phenotypic outcomes can arise from the same chemical cues.
Prognostic importance of tissue velocity imaging during exercise echocardiography in patients with systolic heart failure
Authors: van Zalen Jet , Patel Nikhil R. , Podd Steven J. , Raju Prashanth , McIntosh Rob , Brickley Gary , Beale Louisa , Sturridge Lydia P. , Lloyd Guy W. L.
Published: March 2015

Resting echocardiography measurements are poor predictors of exercise capacity and symptoms in patients with heart failure (HF). Stress echocardiography may provide additional information and can be expressed using left ventricular ejection fraction (LVEF), or diastolic parameters (E/E′), but LVEF has some major limitations. Systolic annular velocity (S′) provides a measure of longitudinal systolic function, which is relatively easy to obtain and shows a good relationship with exercise capacity. The objective of this study was to investigate the relationship among S′, E/E′ and LVEF obtained during stress echocardiography and both mortality and hospitalisation. A secondary objective was to compare S′ measured using a simplified two-wall model. A total of 80 patients with stable HF underwent exercise stress echocardiography and simultaneous cardiopulmonary exercise testing. Volumetric and tissue velocity imaging (TVI) measurements were obtained, as was peak oxygen uptake (VO2 peak). Of the total number of patients, 11 died and 22 required cardiac hospitalisation. S′ at peak exertion was a powerful predictor for death and hospitalisation. Cut-off points of 5.3 cm/s for death and 5.7 cm/s for hospitalisation provided optimum sensitivity and specificity. This study suggests that, in patients with systolic HF, S′ at peak exertion calculated from the averaged spectral TVI systolic velocity of six myocardial segments, or using a simplified measure of two myocardial segments, is a powerful predictor of future events and stronger than LVEF, diastolic velocities at rest or exercise and VO2 peak. Results indicate that measuring S′ during exercise echocardiography might play an important role in understanding the likelihood of adverse clinical outcomes in patients with HF.