bluuebunny/crossref_metadata_2025 huggingface dataset:
Variable Structure of the Cu2S2 Core in Doubly Thiolate-Bridged Dicopper(I) Complexes. An X-Ray Crystallographic, Electrochemical and EPR Study of (dmp)2(o-CH3C6H4S)2Cu2, dmp = 2,9-Dimethyl-1,10-phenanthroline, and a Comment on the Nature of Phenanthroline-Containing “Cu(0)” Complexes
Authors: Stange Andreas F. , Waldhör Eberhard , Moscherosch Michael , Kaim Wolfgang
Published: August 2018

The molecular and crystal structure of the dicopper(I) complex (dmp)2(μ-o-CH3C6H4S)2Cu2 (1), dmp = 2,9-dimethyl-1,10-phenanthroline, has been determined. With Cu/S/Cu and S/Cu/S bond angles between 80 and 100°, the planar structure of the central CuSCuS four-membered ring is much more symmetric for 1 as compared to the analogous complex 2 of unsubstituted 1,10-phenanthroline which has a folded Cu2S2 core with bond angles between 67 and 108°. This result illustrates a considerable structural flexibility of the LCu(μ-SR)2CuL entity which is being discussed as a possible model for CuA centers of cytochrome c oxidase or nitrous oxide reductase. Oxidation of both complexes 1 and 2 remains irreversible even at cyclovoltammetric scan rates of 1 V/s. However, the methyl substitution in complex 1 causes increased reversibility of the electronically coupled dmpbased reduction processes. Accordingly, the EPR spectrum of 1- · is characterized by hyperfine splitting from dmp- · and a relatively small 63,65Cu coupling of 0.53 mT. The stabilization of 2,9-disubstituted 1,10-phenanthroline radical anions by coordination to Cu(I) is also demonstrated by detection of a single broad EPR line at g 2.0028 for the formal “Cu(0)” complex Cu(dpp)2 = CuI(dpp-·)(dpp), dpp = 2,9-diphenyl-1,10-phenanthroline. While the EPR signal of Cu(dpp)2 loses intensity on cooling, possibly due to dimerization and spin-pairing, the distorted tetrahedral configuration with essential orthogonal arrangement of dpp π systems seems to disfavour an intramolecular electron hopping.
Preparation and Crystal Structure of Hg9As4O16, a Mercury Arsenate(V) with Triangular Hg3
4+ Cations
Authors: Wessels Annemarie L. , Jeitschko Wolfgang , Möller Manfred H.
Published: August 2018

The new compound Hg9As4O16 has been prepared by thermal decomposition o f the mercury(I) arsenate(V) (Hg2)3(AsO4)2 in the presence of HgO in an evacuated, sealed silica tube. It crystallizes with a rhombohedral structure (R3c, Z = 6), which has been determined from two single-crystal diffractometer data sets collected at 295 K (a = 1665.3(1) pm, c = 1083.8(1) pm, R = 0.051 for 2353 structure factors and 62 variable parameters) and 170 K (a = 1660.3(2) pm, c = 1083.0(1) pm, R = 0.037 for 1681 F-values). It corresponds to the formula (Hg3
4+)3(AsO4
3-)4 with almost equilateral mercury triangles and nearly perfect ASO4 tetrahedra. The average Hg-Hg bond distance of 267.5 pm is considerably greater than the average Hg-Hg distance of 251.3 pm round in mercury(I) compounds, reflecting the atoms.
Synthese, Kristallstruktur und Eigenschaften von 1,1,3,3,3-Pentaaminol- 1-thio-1 λ5,3λ5-diphosphaz-2-en (NH2)2P(S)N=P(NH2)3 / Synthesis, Crystal Structure, and Properties of 1,1,3,3,3-Pentaam 1-thio-1 λ5,3λ5-diphosphaz-2-en (NH2)2P(S)N=P(NH2)3
Authors: Horstmann Stefan , Schnick Wolfgang
Published: August 2018

(NH2)2P(S)N=P(NH2)3 has been prepared by a two step synthesis. Suitable single crystals were obtained from an acetonitrile solution in a temperature gradient between 60 °C and room temperature. The crystal structure of (NH2)2P(S)N=P(NH2)3 has been determined by single crystal X-ray methods (P21/c, a = 998.27(9) b = 762.78(8), c = 1007.70(15) pm, β = 107.340(7)°, Z = 4). In the crystal structure each hydrogen atom is subject to a hydrogen bond. Four N-H -N hydrogen bonding interactions per molecule build up a framework connecting two molecules in eight-membered rings. Each sulfur atom shows six distances N-H···S in the range of weak hydrogen bonding interactions.
Kristallstrukturen von (n-Bu4N)[B6Cl6], (n-Bu4N)[B6Br6] und (Ph3P=N=PPh3)[B6I6] sowie Schwingungsspektren und Normalkoordinatenanalyse der Hexahalogeno-c/osö-Hexaboratradikalanionen [B6X6]-, X = Cl, Br, I / Crystal Structures of (n-Bu4N)[B6Cl6], (n-Bu4N)[B6Br6], and (Ph3P=N=PPh3)[B6I6], and Vibrational Spectra and Normal Coordinate Analysis of the Hexahalogeno-closo-hexaborate Radical Anions [B6X6]- , X = Cl, Br, I
Authors: Lorenzen V. , Preetz W.
Published: August 2018

Oxidation of hexahalogeno-closo-hexaborates [B6X6]2-, X = Cl, Br, I, with (NH4)2[Ce(NO3)6] in ethanol yields coloured radical ions [B6X6]-. X-ray structure determina­ tions have been performed on single crystals of (n-Bu4N)[B6Cl6] (1) (monoclinic, space group P21/c,a = 13.144(2),6 = 12.594(2),c = 17.688(5) Å, β = 107.29(2)°,Z=4),(n-Bu4N)[B6Br6] (2) (monoclinic, space group P21/c, a = 13.529(5), b = 13.096(5), c = 17.863(5) Å, β = 107.20(5)°, Z = 4) and (Ph3P=N=PPh3)[B6I6] (3) (triclinic, space group P1̄, a = 9.3137(8), b = 10.6988(10), c = 11.8760 Å , a = 102.220(7), β = 99.34J(8), 7 = 96.030(7)°, Z = 1). The average B-B distances are nearly equal (1.733 Å (1), 1.728 Å (2), 1.728 Å (3)) while the B-X distances increase (1.762 Å (1), 1.912 Å (2), 2.120 Å (3)). Using the molecular parameters, normal coordinate analyses have been performed and a good agreement of observed and calculated frequencies of 10B and 11B labelled derivatives has been achieved. The valence force constants fd(BB) and fd(BX) of [B6X6]- are 1.17 and 4.17 (X = Cl), 1.18 and 3.34 (Br) and 1.18 and 2.60 mdyn/Å (I), respectively.
Untersuchungen zur thermischen Zersetzung von Ammoniumlanthanhalogeniden/Investigation on the Thermal Decomposition of Ammonium Halides
Authors: Morgenstern A. , Oppermann H.
Published: August 2018

The decomposition equilibria of Ammonium Lanthanum Halides (NH4)2LaX5 were determined by total pressure measurements in a membrane zero manometer. The phases (NH4)2LaX5 decompose in one step to give solid LaX3 and gaseous NH3 and HX. From the decomposition functions the enthalpies of formation and the standard entropies of the phases are derived.

ΔH°B (NH4)2LaCl5,f,298) = -411 ,7 ± 2,2 kcal/mol; S°((NH4)2LaCl5,f,298) = 86,7 ± 2,3cal/Kmol;

ΔH°B (NH4)2LaBr5,f,298) = -351,6 ± 3,8 kcal/mol; S°((NH4)2LaBr5,f,298) = 101,1 ± 1,8 cal/Kmol;

ΔH°B (NH4)2LaI5,f,298)= -268 ,9 ± 3,9 kcal/mol; S°((NH4)2LaI5,f,298) = 115,5 ± 4,3 cal/Kmol.
Difluorphosphorylcyclosilazane -Synthese und Kristallstruktur/Difluorophosphorylcyclosilazanes -Syntheses and Crystal Structure
Authors: Klingebiel Uwe , Noltemeyer Mathias , Rakebrandt Hans-Jörg
Published: August 2018

The reaction of lithiated 1,3-bis(fluorodimethyl)cyclotrisilazane with PF3 leads to the formation of a PF2-substituted six-membered Si-N ring (1). 1,5-Bis(difluorophosphanyl)-2,2,4,4,6,6,8,8-octamethyl-cyclotetrasilazane (2) is obtained in the reaction of the dilithium derivative of the cyclic tetrasilazane with trifluorophosphane in a molar ratio 1:2. The crystal structure of (F2P-N-SiMe2-NH-SiMe2)2 (2) has been determined.
Ein [Ba(Ca,Mn)O6]-Gerüst mit eingelagerten V-O-V-Gruppen in der Kristallstruktur von Ba(Ca0.6Mn0.4)V2O7 /A [Ba(Ca,Mn)O6] Framework with Incorporated V-O-V Groups in the Crystal Structure of Ba(Ca0.6Mn0.4)V2O7
Authors: Rettich R. , Müller-Buschbaum Hk.
Published: August 2018

Single crystals of Ba(Ca0.6Mn0.4)V2O7 have been prepared by crystallization from melts. X-ray investigations revealed a new quaternary vanadium oxide of the type BaMV2O7. The M positions are occupied statistically by Ca2+ and Mn2+. The compound crystallizes with orthorhombic symmetry, space group D2h
16-Pnma, a = 15.429(2), b - 5.7005(12), c = 7.364(2) Å, Z = 4. The crystal structure can be interpreted as a [Ba(Ca,Mn)O6] network with incorporated V-O- V groups. Considering the nearest O2- neighbours of the incorporated vanadium, the V-O-V groups are complemented to give V2O7 divanadate units. Ba(Ca0.6Mn0.4)V2O7 is isotypic to BaMV2O7 (M=Ca,Cd) but not to BaMnV2O7.
Synthesis and X -Ray Crystal Structure of the Heterobimetallic Complex [FeRh (μ-CO)(CO)3((μ-PBut
2)((μ-Ph2PCH2PPh2)]
Authors: Böttcher Hans-Christian , Merzweiler Kurt , Bruhn Clemens
Published: August 2018

The reaction of the phosphido-bridged metal carbonyl [FeRh(CO)6(μ-PBut
2)] (1) with dppm [dppm = bis(diphenylphosphino)methane] leads to the heterobimetallic complex [FeRh(μ-CO)(CO)3(μ-PBut
2)(μ-dppm)] (2) in good yields. The molecular structure of 2 was determined at room temperature [triclinic, space group P1̄, a = 9.509(6), b = 13.637(5), c = 14.926(8) Å, α = 81.38(4), β = 82.75(4), γ = 71.25(4)°]. The compound acts as a homogeneous catalyst precursor in the hydroformylation reaction of ethylene, but it decomposes during this process.
Synthese und Kristallstruktur von [(Cl3Si)2N]2TiCl2 -ein perchloriertes N-Silyl-titanamid /Synthesis and Crystal Structure of [(Cl3Si)2N]2TiCl2 -a Fully Chlorinated N-Silyl Titanium Amide
Authors: Schwarze Bernd , Milius Wolfgang , Schnick Wolfgang
Published: August 2018

The chlorinated titanium amides [(Cl3Si)2N]2TiCl2 (1) and (Cl3Si)2NTiCl3 have been syn­thesized selectively from hexachlorodisilazane lithium and TiCl4. The crystal structure of 1 was determined by single crystal X-ray methods at room temperature (P212121, a = 1232.4(2), b = 1265.5(2), c -1469.1(2) pm, Z = 4). The central titanium atom of 1 is bound to two nitrogen atoms and two Cl atoms and is weakly coordinated further by two Cl atoms of the trichlorosilyl groups.
Synthesis of C2B3 X-Heterocycles (X = C, N, P, O, S) from 1,3,5-Triborapentanes
Authors: Deforth T. , Kaschke M. , Stock H. , Pritzkow H. , Siebert W.
Published: August 2018

The hydroboration of acetylene with HBCl2 yields the products (Cl2B)2CHMe (1a), (Cl2BCHMe)2BCl (2a), (Cl2BCHMeBCl)2CHMe (3a), and (ClBCHMe)3 (4a). The crystal structure of 4a as well as of the pentaiodo derivative 2b were determined. A mechanism for the formation of the different hydroboration products is proposed. The 1,3,5-triborapentane 2a serves as precursor for the synthesis of derivatives of 1,3,5-triboracyclohexanes, 1,3,5-tribora-2-aza-cyclohexanes, 1,3,5-tribora-2-phospha-cyclo-hexanes, and 1,3,5-tribora-2-thia-cyclohexanes. Their constitutions have been derived from spectroscopic studies. The crystal structure of the 1,3,5-tribora-2-oxa-cyclohexane derivative was also determined.
Reaktionen von Azacoronanden mit Quecksilber(II)iodid: Kristallstrukturen zweier Komplexe von Hgl2 mit Diaza-15-krone-5 und Diaza-18-krone-6 /Reactions of Azacoronands with Mercury(II) Iodide: Crystal Structures of Two Complexes of Hgl2 with Diaza-15-crown-5, and Diaza-18-crown-6
Authors: Pickardt Joachim , Wiese Sven
Published: August 2018

The reactions of diaza-15-crown-5 (“2.1”), and diaza-18-crown-6 (“2.2”), resp., with HgI2 in methanol afford the compounds [Hg(2.1)I][Hg2I6] (1) and [Hg(2.2)I][Hg2I6] (2), the crystal structures of which were determined. 1 consists of isolated cations [Hg(2.1)I]+ and anions [Hg2I6]2-. In the cations Hg is coordinated by one iodine atom, the two N atoms and the three O atoms of the ligand; the Hg-I distance is 262.1(3) pm, the Hg-N bond lengths are 221(2) and 238(2) pm; they are significantly shorter than the Hg-O distances, which are in the range between 262 and 271 pm. 2 consists of cations [Hg(2.2)I]+, which are bridged by the anions. In the cations of 2 Hg is coordinated by an iodine atom and by the two N atoms of the ligand, but by only three of the four O atoms. The Hg-I distance is 275.8(5) pm, the mean Hg-N bond length 234(4) pm, and the Hg-O distances vary between 285 and 304 pm. The Hg-I distance to the bridging I atom of the anion is 388.6(6) pm. The Hg-I bond lengths within the anions are slightly widened by this coordination.
Ein neues Verfahren zur numerischen Berechnung des Madelung-Anteils der Gitterenergie ionischer Kristalle / A New Method for the Numerical Calculation of the Madelung Contribution of the Lattice Energy in Ionic Crystals
Authors: Marx Veit
Published: August 2018

The Madelung contribution to the lattice energy of simple binary crystal structures and lanthanide oxide fluorides with different types of disorder has been calculated by summation of Coulomb interactions and additional consideration of surface effects. In the case of NaCl, CsCl, ZnS and CaF2 the agreement with mathematically exactly calculated values is better than 1 %. For the cubic high temperature modification of YOF it could be shown that a structure with long range order and short range disorder is more favourable from the energetic point of view than a stochastic distribution of the anions over all anion sites of the crystal.
Kristallstrukturen, Schwingungsspektren und Normalkoordinaten- analysen von cis- und trans-[OsX2(acac)2], X = Cl, Br, I / Crystal Structures, Vibrational Spectra and Normal Coordinate Analyses of cis- and trans-[OsX2(acac)2], X = Cl, Br, I
Authors: Dallmann K , Preetz W
Published: August 2018

The crystal structures of trans-[OsCl2(acac)2] (triclinic, space group P1̄, a = 7.4114(5), b = 7.6419(9), c = 7.9944(6) Å, α = 62.692(7), β = 87.687(6), γ = 60.667(6)°, Z = 1), trans-[OsBr2(acac)2] (triclinic, space group P1̄, a = 7.467(3), b = 7.621(3), c = 8.260(3) Å, α = 115.03(3), β = 92.78(3), γ = 117.91(3)°, Z = 1), cis-[OsCl2(acac)2] (monoclinic, space group C2/c, a = 13.8532(13), b = 7.7990(8), c = 13.6202(12) Å, β = 108.375(10)°, Z = 4) and cis-[OsBr2(acac)2] (monoclinic, space group C2/c, a = 13.944(2), b = 8.0347(13), c = 13.743(2) Å, β = 106.757(12)°, Z = 4) have been determined by single crystal X-ray diffraction analysis. To enhance the spectroscopic resolution, the IR and Raman spectra of the six complexes have been measured at low temperature (10 K). Using the molecular parameters of the X-ray determinations normal coordinate analyses based on a modified valence force field have been performed for trans-[OsCl2(acac)2], trans-[OsBr2(acac)2] and cis-[OsCl2(acac)2], and the normal modes of vibration assigned. With sets of 31 or 32 force constants, taking into account the innerligand vibrations, a good agreement between observed and calculated frequencies has been achieved. The valence force constants for the X-Os-X axes are fd(OsCl) = 1.81, fd(OsBr) =1.61 mdyn/Å, and for the Cl′-Os-O* axis are fd(OsCl’) = 1.94, fd(OsO*) = 2.81 mdyn/Å and fd(OsO) ranges from 3.27 to 3.31 mdyn/Å.
Kurze O-O-Abstände einer gemeinsamen Polyederkante bei Verknüpfung von PO4-Tetraedern mit VO6-Oktaedern im Vanadyl-Orthophosphat CaNi(VO)(PO4)2 / Short O-O Distances in Edge Sharing PO4 Tetrahedra and VO6 Octahedra of the Vanadyl- Orthophosphate CaNi(VO)(PO4)2
Authors: Meyer S , Müller-Buschbaum Hk
Published: August 2018

Single crystals of the new compound CaNi(VO)(PO4)2 have been prepared by solid state reactions below the melting point of the oxide mixture in evacuated quartz tubes. X-ray investigations led to orthorhombic symmetry, space group D2h16-Pnma, a =14.113(1), b =6.408(1), c = 7.364(1) Å, Z = 4. The crystal structure shows 1∞[NiO4] and 1∞[VO6P2O3] polyhedra chains closely related to analogous chains in the isotypic compound CdV2O(PO4)2. The short V -O distance of 1.66 Å indicates a vanadyl group as the main difference to CdV2O(PO4)2. The short O-O distance of 2,395 Å of the edge-sharing PO4 tetrahedra and VO6 octahedra is discussed.
Transition Metal Complexes of Diazenes, XL [1] Iron Carbonyl Assisted Formation of Bicyclic 1,2-Dihydropyrazol-3-ones from Pyrazolines and Alkynes
Authors: Kisch Horst
Published: August 2018

The oxidative degradation of a tricyclic dicarbonyl iron complex substituted at the diazaferrole ring by ester groups ( 1b ) does not lead to a bicyclic 1,2,3-diazepinone derivative, as reported recently for the case of the phenyl substituted compound (1a ), but affords the bicyclic 4-stilbenyl-1,2-dihydropyrazol-3-one 2b as shown by X-ray structural analysis. Since 1b is obtained by reaction of two different alkynes with a hexacarbonyldiiron complex of the cyclic 1,2-diazene, the over-all reaction formally consists of the addition of CO and two alkyne molecules to an N = N function affording a vinyl substituted diazacyclopentenone ring, and may be viewed as a type of hetero Pauson-Khand reaction.
Metallkomplexe eines Methoxyalkyl-funktionalisierten 2,3-Dihydroimidazol-2-ylidens/ Metal Complexes of a Methoxyalkyl Functionalized 2,3-Dihydroimidazol-2-ylidene
Authors: Kuhn Norbert , Maichle-Mößmer Caecilia , Niquet Elke , Walker Isabel
Published: August 2018

2,3-Dihydro-1,3-di-3'-methoxypropyl-4,5-dimethylimidazol-2-ylidene (2, Carb) reacts with Pd(MeCO2)2 or Me2SnCl2 to give the complexes (Carb)2Pd(MeCO2)2 (5) and (Carb)SnMe2Cl2 (6), respectively. The X-ray structure analysis of 5 clearly demonstrates the η1-coordination of the carbene ligand in the solid state while NMR data imply a weak Pd-O interaction in solution. In 6, the X-ray structure analysis reveals Sn-O distances close to the sum of the van der Waals-radii.
Synthesis and Structures of Bis(pentafluorophenyl) Selenoxide / Telluroxide
Authors: Klapötke Thomas M. , Krumm Burkhard , Mayer Peter , Ruscitti Oliver P.
Published: August 2018

Bis(pentafluorophenyl) selenoxide and telluroxide were prepared by oxidation of the corresponding selenide and telluride with m-chloroperbenzoic acid. (C6F5)2SeO crystallizes in the triclinic space group P1 with a = 9.9452(9), b = 14.871(2), c = 15.279(2) Å , a = 117.17(1), β = 101.02(1), γ = 95.39(1)°. The telluroxide (C6F5)2TeO crystallizes as a dichloromethane or benzene solvate. The crystallographic data are for (C6F5)2TeO · CH2Cl2: monoclinic space group P21/n with a = 18.1918(2), b = 7.7545(1), c = 23.1719(3) Å , β = 97.9523(4)°; for (C6F5)2TeO ÿ 1/2C6H6: triclinic space group P1̄ with a = 5.7064(1), b = 10.9473(1), c = 12.1476(1) Å , a = 81.5366(8), γ = 86.8528(8), γ = 88.0700(5)°. The selenoxide forms hexamers, the telluroxide forms strong dimers with chalcogen-oxygen interactions.
Pollen Growth Regulator, Fusanolide A, and a Related Metabolite from Fusarium sp.
Authors: Shimada A. , Kusano M. , Matsumoto K. , Nishibe M. , Kawano T. , Kimurab Y.
Published: August 2018

Fusanolides A (1) and B (2) were isolated from cultures of the fungus Fusarium sp. as pollen growth regulators and their structures were established by spectroscopic evidence. 1 completely inhibited pine pollen germination and tea pollen tube growth at a concentration of 300 mg/l, but 2 showed no inhibitory effect on them at the same concentration.
Liegen in Imidazolium-Tetrafluoroboraten Wasserstoffbrückenbindungen vor? Die Struktur von 1,3-Diisopropyl-4,5-dimethylimidazolium- Tetrafluoroborat [1] / Is Hydrogen Bonding Present in Imidazolium Tetrafluoroborates? The Structure of 1,3-Diisopropyl-4,5-dimethylimidazolium Tetrafluoroborate [1]
Authors: Kuhn Norbert , Walker Michael , Steimann Manfred
Published: August 2018

1,3-Diisopropyl-4,5-dimethylimidazolium tetrafluoroborate (2) is obtained from 2,3-dihydro-1,3- diisopropyl-4,5-dimethylimidazol-2-ylidene (1) and HBF4 • Et 2O; the X-ray structure of 2 is reported.
Synthesis of AM15C5 Bonded Merrifield Peptide Resin and its Separating Properties
Authors: Kim Dong Won , Kang Byung Moo , Lee Nam-Soo , Kim Chang Suk , Ryu Haiil , Hong Young Guan
Published: August 2018

A 2-aminomethyl-15-crown-5 (AM15C5) bonded Merrifield peptide resin was synthesized. The capacity of this crown ion exchanger was 2.25 meq/g of dry resin. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. The hydration and isotope mass effects dominated over those of the complexation and properties of the exchanger. The separation factors of 24Mg2+/25Mg2+, 24Mg2+/26Mg2+, and 25Mg2+/26Mg2+ isotope pair fractionations were 1.0012, 1.0023, and 1.0011, respectively.
An Improved Synthesis of Nickel-bis[5,6-dihydro-1,4-dioxine- 2,3-dithiolate], Ni(edo)2
Authors: Papavassiliou G. C. , Mousdis G. A. , Anyfandis G. C.
Published: August 2018

Starting from 2,3-dichloro-1,4-dioxane, the title compound was prepared by a five-step chemical procedure, instead of a eight-step procedure reported recently.
Silanolato-Komplexe von Vanadium (III, IV) / Silanolato Complexes of Vanadium (III, IV)
Authors: Preuss Fritz , Werle Peter
Published: August 2018

Syntheses of the homoleptic trimethylsilanolato complexes V(OSiMe3)3 and V(OSiMe3)4 are described. The thiovanadium(V)compound VS(OSiPh3)3 (11) is formed from [V(OSiPh3)3- (THF)2] upon oxidation with elemental sulfur; 11 has been characterized by 51V NMR spectroscopy.
Polysulfonylamine, CLV [1]. Starke und schwache Wasserstoffbrücken in den Kristallstrukturen von 2,2΄-Bipyridinium-, 1,10-Phenanthrolinium- und 1,8-Bis(dimethylamino)naphthalinium-dimesylamid / Polysulfonylamines, CLV [1]. Strong and Weak Hydrogen Bonding in the Crystal Structures of 2,2΄-Bipyridinium, 1,10-Phenanthrolinium and 1,8-Bis(dimethylamino)naphthalinium Dimesylamide
Authors: Henschel Dagmar , Moers Oliver , Lange Ilona , Blaschette Armand , Jones Peter G
Published: August 2018

As a sequel to prior reports on strong and weak hydrogen bonding in onium di(methanesulfonyl) amide crystals, low-temperature X-ray structures are described for three salts of general formula BH+(MeSO2)2N-, where BH+ is 2,2΄-bipyridinium (1; monoclinic, space group P21/n, Z΄ = 1), 1,10-phenanthrolinium (2; monoclinic, P21/c, Z΄ = 2), or 1,8-bis(dimethylamino) naphthalinium (3; orthorhombic, P212121, Z΄ = 1). Monoprotonation of the organic bases by (MeSO2)2NH results in the formation of an intra-cation N-H···N hydrogen bond, which is asymmetric in 1 and 2, but approximately symmetric in the proton-sponge cation of 3. Moreover, the acidic H atom is engaged in a cation-anion contact N-H···N- in 1 and 2 or H+···Oδ- in 3, thus conferring three-centre character upon the strong hydrogen bonding. Each structure displays a multitude of close interionic C-H···O/N contacts that are geometrically consistent with weak hydrogen bonding. A salient feature is provided by short S-CH2-H···O-S inter-anion contacts, which lead to layers in 1 and to catemers in 2, but are non-existent in structure 3. The cations of both 1 and 2 form π-stacks that are intercalated between the anion layers or surrounded by six anion catemers, whereas in structure 3 each cation is octahedrally coordinated by six anions and vice-versa. The heteroionic connectivity comprises the aforementioned branches of the strong three-centre hydrogen bonds (in 1-3), numerous Car-H···A bonds (1, 2: A = O; 3: A = O, N), S-CH2-H···Nring interactions (1, 2), and close N-CH2-H···O=S contacts (3; possibly destabilizing).
Borate, an Effective Mummification Agent in Pharaonic Egypt
Authors: Weser Ulrich , Kaup Yoka
Published: August 2018

Mummification salts and mummified bones were assayed for borate. In two samples of mummification salt one from Deir el-Bahari (26th Dynasty, 700-600 BC) and salt from the embalming material of Tutankhamen (18th Dynasty, 1370-1335 BC) 3.9 and 2.1 μMol borate/ gram were found, respectively. Six mummified bone fragments from the Old Kingdom contained up to 1.2 μMol/gram. It is suggested that borate containing salt was used during mummification. The reactivity of borate on bone alkaline phosphatase, which is known to survive mummification for more than 4000 years, was examined. Borate forms high relative molecular mass adducts of this enzyme being temperature resistant and functionally distinct.
Structural, Spectroscopic and Theoretical Studies of (tButyl-isocyanide)gold(I) Iodide
Authors: Liau Ruei-Yang , Mathieson Trevor , Schier Annette , Berger Raphael J. F. , Runeberg Nino , Schmidbaur Hubert
Published: August 2018

The complexes (tBuNC)AuCl and (tBuNC)AuI 13C-labeled at the isocyanide group were prepared and investigated by concentration- and temperature-dependent IR and NMR spectroscopy in dichloromethane solution. No indication for association of the molecules was obtained. The crystal structure of the iodide complex was determined by X-ray diffraction methods and shown to feature only monomers with extremely large intermolecular Au-Au contacts of 4.162 Å, well beyond the sum of the van der Waals radii. It therefore appears that (tBuNC)AuI is a rare example of a sterically non-hindered L-Au-X complex which shows no aurophilic interactions whatsoever. In a quantum-chemical analysis (at the local MP2 level) of the dimerization of the model compounds (MeNC)AuCl and (MeNC)AuI in various dimer geometries it was demonstrated that the energy-balance of the dimerization is very delicate and not dominated solely by contributions from correlation / relativistic (aurophilic) effects.
X-Ray and Raman Investigations on Cyanides ofMono- and DivalentMetals and Synthesis, Crystal Structure and Raman Spectrum of Tl5(CO3)2(CN)
Authors: Reckeweg Olaf , Simon Arndt
Published: August 2018

Pseudobinary cyanides of monovalent and divalent metals were synthesized, and X-ray and Raman data of the cyanides were measured. Single crystal X-ray structure analyses were performed on Zn(CN)2 (Pn3̄m (No. 224), a = 591.32(7) pm), Hg(CN)2 (I4̄2d (No. 122), a = 969.22(14) and c = 890,15(18) pm) and for the first time on AgCN (I4̄2d (No. 166), a = 600.58(8) and c = 526.28(11) pm). The data are compared with literature data. The reaction of TlF and NaCN in 25% aqueous ammonia solution in air led to Tl5(CO3)2(CN) which was characterized by X-ray (Cmca (No. 64), 1468.1(3), 1171.6(2) and 1266.0(3) pm) and Raman spectroscopy.
A New Mixed Valent Europium Chloride: Na5Eu7Cl22
Authors: Wickleder Claudia
Published: August 2018

The reaction of NaCl, EuCl2 and EuCl3 yields violet crystals of the new mixed valent chloride Na5Eu7Cl22 which crystallizes with a hitherto unknown structure (orthorhombic, Pmmn, Z = 2, a = 2525.9(4), b=846.91(9), c = 781.72(8) pm). The structure contains four crystallographically different europiumions,which can be attributed toEu2+ or Eu3+ with respect to their coordination numbers and Eu-Cl distances. The [EuClx] coordination polyhedra are connected to chains along the [001] direction. Absorption spectra show transitions which can be assigned either to Eu3+ or Eu2+ ions or to intervalence charge transfer transitions (IVCT). The latter are at lower energy compared to other mixed valent europium chlorides. The occurence of IVCT and the number of the crystal field levels of the Eu3+ ions reveal that the sites of the europium ions are occupied for a small amount by ions of the respective other valence.
Polysulfonylamine, CLVII [1]. Molekulare Cokristalle aus Di(4-halogenbenzolsulfonyl)aminen und Sauerstoffbasen: Lamellare Schichten mit engen Zwischenschichtkontakten der Art C-H···Hal, Cl ··· Cl oder Br ··· Br / Molecular Co-crystals of Di(4-halobenzenesulfonyl)amines and Oxygen Bases: Lamellar Layers with Close C-H···Hal, Cl · · · Cl or Br · · · Br
Authors: Hamann Thomas , Henschel Dagmar , Lange Ilona , Moers Oliver , Blaschette Armand , Jones Peter G.
Published: August 2018

Di(4-fluorobenzenesulfonyl)amine (DFBSA), di(4-chlorobenzenesulfonyl)amine (DCBSA) or di(4-bromobenzenesulfonyl)amine (DBBSA) were co-crystallized with equimolar amounts of pyridine-N-oxide (PyO), dimethyl formamide (DMF) or 1,3-dimethylurea (DMU), respectively, to form the supramolecular complexes DFBSA·PyO (1; triclinic, space group P1 , Z = 1), DCBSA·DMF (2; monoclinic, P21/n, Z = 1) and DBBSA·DMU (3; triclinic, P1 , Z = 1). Throughout the triad, the molecules are ordered into lamellar layers parallel to the xy plane. Owing to the folded conformations of the disulfonylamines, the layers display an inner polar region of oxygen bases and (SO2)2NH groups, outer apolar regions of aromatic rings, and interlayer regions hosting the halogen atoms. These arrays mimic the formerly reported structures of a series of ionic metal di(arenesulfonyl)amides. The intralamellar connectivity is governed by conventional hydrogen bonding and weak C-H···O bonds, the former comprising in structure 1 a very strong N-H···O-N interaction [N···O 250,9(2) pm, N-H···O 171(3)°], in 2 an N-H···O=C bond, and in 3 a set of one S2N-H···O=C and two N-H(urea)···O=S bonds. A centrosymmetric (PyO)2 dimer is present in structure 1. The juxtapositions of adjacent layers reflect halogen-specific recognition patterns (1: three short C-H···F sequences, all F···F distances beyond the van der Waals limit dW; 2: one short C-H···Cl sequence and one close Cl ··· Cl contact < dW, all other Cl ··· Cl > dW; 3: four short C-H···Br sequences and one close Br···Br contact < dW, all other Br···Br > dW). The interhalogen contacts in 2 and 3 are of the type I, as characterized by θ(C-X···X')≈ θ(C'-X' ··· X); the four angles θ lie in the range 166-175°
Synthesis, Crystal Structures and Investigations on the Thermal Properties of New CuBr(2-Ethylpyrazine) Coordination Polymers
Authors: N¨ather Christian , Jeß Inke
Published: August 2018

The new 3:2 coordination polymer catena[Cu3Br3 (μ2-2-ethylpyrazine-N,N')2] (I) was prepared by the reaction of CuBr with 2-ethylpyrazine in acetonitrile at room temperature. Its crystal structure consists of Cu3Br3 rings which are connected by the 2-ethylpyrazine ligands to chains. The 2:1 compound poly[Cu2Br2(μ2-2-ethylpyrazine-N,N')] (II) was only obtained phase pure if the reaction was performed at 100 °C. In this compound CuBr single chains occur, which are connected to sheets by the 2-ethylpyrazine ligands. If compound I is heated it decomposes in two separate steps as shown by thermogravimetry (TG), differential thermoanalysis (DTA) and mass spectroscopy (MS). Ex situ and temperature dependent in situ X-ray powder diffraction experiments prove that in the first step the 2:1 coordination polymer II has formed as the phase pure compound which decomposes to CuBr in the second step. From heating rate dependent TG measurements there is no hint for the occurrence of additional intermediates during the thermal decomposition reaction.
Novel Non-Symmetric Nickel-Diimine Complexes for the Homopolymerization of Ethene: Control of Branching by Catalyst Design
Authors: Schmid Markus , Eberhardt Robert , Kukral Jürgen , Rieger Bernhard
Published: August 2018

Non-symmetric diimine ligands (Ar-N=C(CH3)-(CH3)C=NAr*; Ar: 2,6-diisopropyl-phenyl; Ar*: 2,6-di(4-tert-butyl-phenyl)phenyl (4b), 2,6-di(4-OCH3)-phenyl)phenyl (4c)) were synthesized and converted in-situ into the corresponding nickel dibromo complexes (5b, c) by reaction with (DME)NiBr2. The complexes were activated for ethene polymerization by treatment with MAOat ambient temperature. The resulting highmolecular weight polymer products (MW > 4.0 x 106 g mol-1) have a branched microstructure (predominantly methyl groups), as indicated by 13C NMR spectroscopy. The degree of branching can be controlled by a proper choice of the 2,6-diphenyl modified aniline moieties resulting in melting transitions ranging from 92 - 130 °C.
Neue Pnictide im CaAl2Si2-Typ und dessen Existenzgebiet/New Pnictides with the CaAl2Si2 Type Structure and the Stability Range of this Type
Authors: Wartenberg Franziska , Kranenberg Christian , Pocha Regina , Johrendt Dirk , Mewis Albrecht , Hoffmann Rolf-Dieter , Mosel Bernd D. , Pöttgen Rainer
Published: August 2018

Five new compounds were synthesized by heating mixtures of the elements at 600 - 1000 °C and investigated by powder and single crystal X-ray methods. EuMg2P2 (a = 4.280(1), c = 7.164(3) Å), EuMg2As2 (a = 4.393(1), c = 7.321(1) Å),EuMg2Sb2 (a = 4.695(1), c = 7.724(2) Å), YbMg2Sb2 (a = 4.650(1), c = 7.540(2) Å), and SrLiAlSb2 (a = 4.584(3), c = 7.697(9) Å) crystallize with the CaAl2Si2 type structure (P3̄m1; Z = 1). The magnetic susceptibility of EuMg2Sb2 shows Curie-Weiss behavior with an experimental magnetic moment of 7.48(2) μB/Eu atom and a Weiss constant θ = 3.2(1) K. EuMg2Sb2 is ordered antiferromagnetically at 8.2(3) K. Magnetisation measurements at 4.5 K show a linear increase and a saturation for a magnetic moment of 5.9(1) μB/Eu at 5.5 T, indicating an almost parallel spin alignment with increasing field strength. 151Eu Mössbauer spectra at 78 K show an isomer shift of -11.69(5) mm/s, compatible with divalent europium. At 4.2 K we observe full hyperfine field splitting with 23 T. The 121Sb spectrum at 4.2 K shows a transferred hyperfine field of 8(2) T at an isomer shift of -7.9(3) mm/s. From the band structure of EuMg2Sb2 we draw the conclusion, that analogous compounds of trivalent rare-earth metals with CaAl2Si2 type structure should not exist due to electronic reasons.
Synthesis, Structural and Spectroscopic Characterization of the α,ω-Diammonioalkane Hexabromorhodates( III) [H3N(CH2)xNH3]2[H5O2][RhBr6]Br2 (x = 3, 4) – IR Spectra of [H5O2]+ Ions with Weak Solid State Interactions
Authors: Bujak Maciej , Frank Walter
Published: August 2018

The reaction of rhodium(III) chloride trihydrate with 1,3-diaminopropane and 1,4-diaminobutane in concentrated hydrobromic acid results in the formation of the bis(α,ω-diammonioalkane) diaquahydrogen(1+) hexabromorhodate(III) dibromides [H3N(CH2)xNH3]2[H5O2][RhBr6]Br2 (x = 3, 4). Dark red single crystals were obtained by diffusion-controlled crystallization at room temperature. Both compounds crystallize in space group type P1̄ and their structures are closely related. In view of crystal engineering they are inorganic-organic hybrid materials built up from octahedral [RhBr6]3−, simple Br− and flexible chain-like [H3N(CH2)xNH3]2+ ions with the [H5O2]+ and further Br− ions incorporated and thus might be considered as addition compounds [H3N(CH2)xNH3]2[RhBr6]Br ∙ [H5O2]Br. Cationic and anionic moieties in the crystal are held together by a complex system of N-H∙∙∙Br and O-H∙∙∙Br hydrogen bonds. Geometric features of O-H∙∙∙Br hydrogen bonding as well as the pronounced disorder of the [H5O2]+ ions in the diammoniopropane salt indicate the weak association of these species in the solids. Weak association of the ions is also documented by difference ATR-FT-IR spectra of the compounds and related diammonioalkane dibromides that show the stretching modes of the terminal O-H bonds above 3300 cm−1. Further characteristic bands are recognized at ca. 1635 (s), 985 (vs), and 670 (m) cm−1.
A New Copper (II) Complex with the N,N'-Bis(antipyryl-4-methyl)-piperazine (BAMP) Ligand: [Cu(BAMP)](ClO4)2
Authors: Costișor Otilia , Tudose Ramona , Pantenburg Ingo , Meyer Gerd
Published: August 2018

The synthesis of the Mannich base N,N’-bis(antipyryl-4-methyl)-piperazine (BAMP) (1), its crystal structure as well as the synthesis and the crystal structure of the copper complex Cu(BAMP)(ClO4)2 (2) are reported. C28H34N6O2 ∙ 4H2O (BAMP ∙ 4H2O) crystallizes with triclinic symmetry, space group P1̄, lattice parameters: a = 704,9(2), b = 983,4(2), c = 1198,9(3) pm, α = 68,72°, β = 73,62°, γ = 78,49°. The copper-complex Cu(BAMP)(ClO4)2 crystallizes with tetragonal symmetry, space group P42/n, lattice parameters: a = 2295,1(3), c = 1412,2(2) pm. The copper(II) atom is five-coordinate by the two nitrogen atoms belonging to the piperazine ring and the oxygen atoms of the antipyrinemoieties. The geometry of the copper(II) atom can be described as a square-based pyramid with the N2O2 donor atoms of BAMP forming the basal plane and an oxygen atom of the neighbouring complex molecule occupying the apical position. BAMP acts as a tetradentate ligand, which incorporates a piperazine-fused ring. The structural parameters illustrate well the reinforcing effect exerted by the double “straps” of the piperazine molecule.
Reaktionen von Vanadium(V)- und Tantal(V)-Komplexen Mit Kinetisch Stabilisierten Phosphaalkinen. Einfache Synthese von 1,3,4-Thia- und 1,3,4-Selenadiphospholen / Reactions of Vanadium(V) and Tantalum(V)-Complexes with Kinetically Stabilized Phosphaalkynes. A Simple Synthesis of 1,3,4-Thia and 1,3,4-Selenadiphospholes
Authors: Peters Christoph , Fischbeck Uwe , Tabellion Frank , Regitz Manfred , Preuss Fritz
Published: August 2018

A simple synthetic pathway to the unknown 1,3,4-thiadiphospholes 3 and 1,3,4- selenadiphospholes 4 has been developed involving reactions of the azaphosphavanada(V)- cyclobutenes 2, generated in situ from the imidovanadium(V) complex tBuN = VCl3 and the phosphaalkynes 1a - d, with an excess of elemental sulfur or grey selenium, respectively. The reactions of the phosphaalkynes 1a,b with TaOCl3 or VOCl3 · DME furnish the 1,2-dichloro-phosphaalkenes 5a,b and 1,2,3,4-tetrachloro-3,4-di-tert-butyl-1,1-diphosphethane 7a. The metallacyclic species 2e - h with secondary or primary alkyl groups on the ring nitrogen atom are unstable and undergo quantitative conversion to the 1H-1,2,4-azadiphospholes 8, whereas in the presence of an excess of phenylacetylene the 1H-1,2-azaphospholes 9e - h, are formed selectively. A catalytic reaction course has been demonstrated for the cyclotrimerization of phenylacetylene and 2-butyne initiated by small amounts of TaSCl3. The syntheses of the vanadium(IV) complexes [tBuN = VCl2 · 2Py] and [tBuN = VCl2 · TMEDA] are also described starting from tBuN = VCl3 and phosphaalkene 12.
The Hexakis(N,N'-Dimethylurea)Cobalt(Ii) Cation: A Flexible Building Block for the Construction of Hydrogen Bonded Networks
Authors: Papaefstathiou Giannis S. , Keuleers Robby , Milios Constantinos J. , Raptopoulou Catherine P. , Terzis Aris , Desseyn Herman O. , Perlepes Spyros P.
Published: August 2018

The ligand N.N'-dimethylurea (DMU) is used to propagate the octahedral coordination geom- etry of [Co(DMU)6]2+ into 1D and 2D assemblies via a combination of coordinative bonds and interionic hydrogen-bonding. Compounds [Co(DMU)6](ClO4)2 (1), [Co(DMU)6](BF4)2 (2) and [Co(DMU)6](NO3)2 (3) have been prepared from the reactions of DMU and the appropriate hydrated cobalt(II) salts in EtOH. MeCN or Me2CO (only for 1) in the presence of 2,2-di- methoxypropane. Crystal structure determinations demonstrate the existence of [Co(DMU)6]2+ cations and CIO4
- , BF4
- or NO3
- counterions. The great stability of the [Co(DMU)6]2+ cation in the solid state is attributed to a pseudochelate effect which arises from the existence of strong intracationic N-H···O(DMU) hydrogen bonds. The [Co(DMU)6]2+ cations and counterions self- assemble to form a hydrogen-bonded ID architecture in 1, and different 2D hydrogen-bonded networks in 2 and 3. The precise nature of the resulting supramolecular structure is influenced by the nature of the counterion. Two main motifs of intermolecular (interionic) hydrogen bonds have been observed: N-H ···O(ClO4
-, NO3
-) or N-H ··· F(BF4
-) and weak C-H F(BF4
- ) or C-H-O(NO3
- ) hydrogen bonds. The complexes were also characterized by vibrational spec- troscopy (IR, far-IR. low-frequency Raman). The spectroscopic data are discussed in terms of the nature of bonding and the know;n structures.
Preparation, Crystal and Magnetic Structure of the Double Perovskites Ca2TWO6 (T = Co, Ni)
Authors: Martínez-Lope M.J. , Alonso J.A. , Casais M.T. , Fernández-Díazb M.T.
Published: August 2018

Ca2TWO6 (T = Co, Ni) perovskites have been prepared in polycrystalline form by thermal treatment, in air, of previously decomposed citrate precursors. These materials have been studied by X-ray (XRD) and neutron powder diffraction (NPD) data. Our results show that these compounds crystallize, at room temperature, in the monoclinic space group P21/n. The two perovskites contain divalent T (T = Co, Ni) cations. The low temperature antiferromagnetic ordering has been followed from sequential NPD data. Peaks of magnetic origin appear at the NPD patterns below temperatures of TN = 36 K and TN = 56 K for the Co and Ni compounds, respectively. The magnetic structures are both defined by a propagation vector k = (1/2, 0, 1/2), and can be described as an array of ferromagnetic layers of Co(Ni) moments, perpendicular to the [101] directions, coupled antiferromagnetically.
Zur gezielten Synthese funktionell substituierter Oligosilane aus Silyltriflaten und Aminosilyllithiumverbindungen / Tailor-Made Synthesis of Functional Substituted Oligosilanes from Silyl Triflates and (Aminosilyl)Lithium Compounds
Authors: Uhlig Wolfram
Published: August 2018

Diethylamino substituted silyllithium compounds have been prepared in situ from the corresponding phenylchlorosilanes and lithium. These reagents undergo coupling reactions with triflate derivatives of silanes and oligosilanes. Exchange processes analogous to metal halogen exchange and Si-Si bond cleavage, which are side reactions with chlorosilanes, were not observed. Based on the coupling reaction and the amino-to-triflate transformation, functionalized tri-, tetra-, penta- und hexasilanes have been synthesized. α,ω-Triflate substituted oligosilanes containing π-systems have also been obtained. These compounds are useful building blocks for new organosilicon polymers. The formation of the silicon polymers at low temperatures, in short reaction times, and with high yields is reported. The 29Si NMR spectra indicate a regular, alternating arrangement of the building blocks in the polymer backbone.
High-Pressure Preparation, Crystal Structure, and Properties of RE4B6O15 (RE = Dy, Ho) with an Extension of the “Fundamental Building Block”-Descriptors
Authors: Huppertz Hubert
Published: August 2018

High-pressure/high-temperature conditions of 8 GPa and 1000°C were used to synthesize

the new rare earth oxoborates RE4B6O15 (RE = Dy, Ho) in a Walker-type multianvil apparatus.

The single crystal X-ray structure determination of Ho4B6O15 revealed the following

data: C2/c, a = 1164.1(1), b = 436.7(1), c = 1882.5(1) pm, β = 96.71(1)°, Z = 4, R1 = 0.0291, wR2 = 0.0505 (all data). The two isotypic compounds exhibit a new structure type built up from corrugated layers of BO4 tetrahedra. In contrast to all known oxoborates the linking

of the BO4 tetrahedra is partially realized via common edges. Regarding the “fundamental

building block”-concept, we introduce a new descriptor “

” for edge-sharing BO4 tetrahedra.

Temperature-resolved in situ powder diffraction measurements and IR/Raman-spectroscopic

investigations on Dy4B6O15 are also reported.
A New Prenylated Hydroquinone from the Roots of Garcinia atroviridis Griff ex T. Anders (Guttiferae)
Authors: Permana Dharma , Lajis Nordin Hj. , Shaari Khozirah , Ali Abdul M. , Mackeen Mukram M. , Kitajima Mariko , Takayama Hiromitsu , Aimi Norio
Published: August 2018

A continuing study on the phytochemical constituents of Garcinia atroviridis Griff ex T. Anders (Guttiferae) has led to the isolation of a new prenylated hydroquinone from the roots of the plant. The compound has been elucidated to be 4-methylhydroatrovirinone, primarily by the use of gradient NMR and mass spectroscopy. The roots also yielded the known morelloflavone and its 7-O-β-D-glucopyranoside, fukugiside, together with 14-cis-docosenoic

acid.
Three-Membered Ring Formation by Si···N Interactions in Aminosulfenylsilanes
Authors: Mitzel Norbert W.
Published: August 2018

The reaction of dimethylaminosulfenylchloride Me2NSCl with trichlorosilane HSiCl3 and triethylamine gives elemental sulphur and Me2NSiCl3. The aminosulfenylsilane Me2NSSiCl3 is postulated to be an intermediate of this reaction. Ab initio calculations (MP2/6D311G(d,p)) on Me2N-S-SiH3, Me2N-S-SiH2Cl, Me2N-S-SiH2F, and Me2N-S-SiCl3 have been carried out, demonstrating the occurrence of acute valence angles at sulphur and short Si···N distances, which are indicative of NSSi three-membered rings. The strength of the Si · · · N interactions depends on the electronegativity of the substituent at silicon in anti-position to the nitrogen atom and is strongest in the anti conformer of Me2N-S-SiH2F (< NSSi 68°, Si···N 2.208 Å ). The coordination spheres of the nitrogen atoms in the Me2N-S-SiR3 molecules are steeply pyramidal, which is in contrast to the planarised N atoms in other SNMe2 compounds, such as Me2NSCl. The crystal structure of this compound has been determined, as well as that of the product of the above reaction, Me2NSiCl3. Both have planar coordination geometries at the nitrogen atoms.
Synthesis and Structure of 1-{2,2-Dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3- dioxan-5-yl}pyridinium Ylide: A New Route to Meldrum’s Acid Derivatives
Authors: Kuhn Norbert , Al-Sheikh Ahmed , Steimann Manfred
Published: August 2018

2-Bromo-5,5-dimethyl-4,6-dioxo-1,3-dioxine (3) reacts with pyridine and aqueous potassium carbonate to give 1-{2,2-dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3-dioxan-5-yl}pyridinium ylide (5). The crystal structure analysis confirms the betaine nature of 5 consisting of two distored ring fragments [interplanar angle 58.0(4)°] connected by a C-N single bond [1.440(1) Å ].
Crystal Structure and Magnetic Properties of a Dinuclear Iron(III) Doubly Oxygen Bridged Schiff Base Complex
Authors: Elmali A. , Elerman Y. , Zeyrek C. T. , Svoboda I.
Published: August 2018

[Fe(L)Cl]2 (L = N-(4-methylphenyl)-3-methoxy-salicylaldimimine) was synthesized and its crystal structure determined. [C30H26Cl2Fe2N2O6], triclinic, space group P 1̄ , a = 9.278(2), b = 9.4050(10), c = 10.489(2) Å , α = 64.43(2), β = 74.540(10), γ = 62.40(2)° , V = 729.1(2) Å 3, Z = 1. Two identical [Fe(L)Cl] fragments, related by an inversion center, are connected by two bridging O atoms to form a binuclear unit. The iron(III) centers are separated by 3.196(2) Å and weakly antiferromagnetically coupled (J = -10.1(1) cm-1), as derived from temperature-dependent magnetic susceptibility measurements in the range 5.1-283.5 K.
Carboxylic Acid Analogues of Fosmidomycin
Authors: Kurz Thomas , Geffken Detlef , Wackendorff Claudia
Published: August 2018

N-Alkylation of N-Boc-O-benzylhydroxylamine (1) with benzyl 4-bromobutyrate (2) in DMF gave N,O-bisprotected benzyl 4-hydroxyamino-butyrate (3), which was converted into 4-benzyloxyamino-butyric acid benzyl ester (4) with TFA in methylene chloride. Treatment of 4 with formic acid/acetic anhydride or various acid chlorides followed by catalytic hydrogenation led to 4-(N-acyl-N-hydroxyamino)-butyric acids 6.
Zinc Bis[μ-N,N′-chlorozinc-bis(N-trimethylsilylimino- diphenylphosphoranyl)- methanediide]: A Zinc Derivative of a Geminal Carbdianion
Authors: Bollwein Tobias , Westerhausen Matthias , Pfitzner Arno
Published: August 2018

The trinuclear title compound, C74H88Cl2N4P4- Si4Zn3, is derived from a geminally substituted carbdianion. The central zinc atom shows a nearly linear coordination geometry with very short Zn- C bond lengths (average 191 pm). The peripheral metal centers of the chlorozinc moieties are chelated by the phosphanimine donors and hence are triply coordinated, thus forming a six-membered CP2N2Zn ring with Zn-N distances of 195 pm (average).
Semi-Hydrogenated, Asymmetric Metallocene Catalysts for the Propylene Polymerization
Authors: Schloegla Martin , Trolla Carsten , Thewaltb Ulf , Riegera Bernhard
Published: August 2018

The hydrogenation of rac-[1-(9-η5-fluorenyl)-2-(5,6-cylopenta-2-methyl-1-η5-indenyl)ethane] metallocene dichlorides (1a: Zr, 1b: Hf) with PtO2/H2O/H2 is reported. The diastereoselective formation of exclusively rac-[1-(2,3,4,5,6,7,8,9-octahydro-η5-fluorenyl)-2-(2-methyl- 1,4,4a(R;S),5,6,7,7a(S;R),8-octahydro-s-η5-indacenyl)ethane]metallocene dichlorides (2a: Zr, 2b: Hf) was shown by 1H-NMR and by X-ray analysis of 2a. Both compounds were activated in situ with triisobutylaluminum/PhC+
3 [B(C6F5)4]D and tested as catalysts in propylene polymerization reactions. Comparison to the non-hydrogenated complexes revealed a decrease in molecular weight of the polymer and in catalyst activity. Experiments at elevated temperatures resulted in a lower stereospecificity and reduced isotacticity values indicating a polymerization mechanism analogous to C2-symmetric catalysts.
Isolation and Structure Determination of Phenazostatin D, a New Phenazine froma Marine Actinomycete Isolate Pseudonocardia sp. B6273
Authors: Maskey Rajendra P. , Kock Ines , Helmke Elisabeth , Laatsch Hartmut
Published: August 2018

A new phenazine derivative, phenazostatin D (1a), was isolated from an extract of the actinomycete isolate Pseudonocardia sp. B6273 via a TLC-guided chemical screening. The structure of the compound was assigned by spectroscopic methods and found to be the meso-form of phenazostatin B (1b). Phenazostatin D was inactive against the tested bacteria and fungi. The strain also produced the known phenazine antibiotic methyl saphenate (2).
A New Diterpene from Dictyota crenulata
Authors: Soto H. , Rovirosa J. , San-Martín A.
Published: August 2018

Chemical analysis of the brown alga Dictyota crenulata, family Dictyotaceae, collected at Easter Island, yielded a new diterpene. The structure was determined on the basis of spectroscopic evidence. The insecticidal activity of two diterpenes towards the tomato moth Tuta absolute (Povolny) was tested.