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2000 (185)
101Author    TalebH. Al-TelRequires cookie*
 Title    Carbohydrates to Pyrano-Furanoids: New and Regioselective Palladium-Catalyzed Syntheses of Tetrasubstituted Furanoids from Carbohydrate Scaffolds  
 Abstract    A new strategy for the asymmetric syntheses of polysubstituted pyrano-furanoids using allylic sulfates derived from carbohydrate precursors and the dianion of diethoxycarbonyl acetone, catalyzed by Pd(0), is described. 
  Reference    Z. Naturforsch. 55b, 657—660 (2000); received March 27 2000 
  Published    2000 
  Keywords    Dihydrofuran, Carbohydrates, Palladium 
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 Identifier    ZNB-2000-55b-0657 
 Volume    55 
102Author    RaidJ. Abdel-Jalil3, Muhammad Saeeda, Peter Heegb, Wolfgang Voelter3Requires cookie*
 Title    Synthesis and Properties of Selected 4-Substituted Anhydro Sugars  
 Abstract    A new class of 4-deoxy-4-([4-substituted-l-piperazinyl], [4-morpholinyl] and [4-( 
  Reference    Z. Naturforsch. 55b, 661—666 (2000); received February 15 2000 
  Published    2000 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0661.pdf 
 Identifier    ZNB-2000-55b-0661 
 Volume    55 
103Author    TakuoA., Hisashi Miyagawa3, Tamio Ueno3, Nobuo HamRequires cookie*
 Title    Production of 5,7-Dihydroxy-6-hydroxymethyl-2-methoxy-l,4-naphthoquinone by the Cultured Lichen Mycobiont of Opegrapha sp. No. 9771836  
 Abstract    Lichen, Mycobiont, Naphthoquinone A new pigment was isolated from an osmotically-stressed culture of the lichen mycobiont of Opegrapha sp. and the structure was determined to be 5, 7-dihydroxy-6-hydroxymethyl-2-methoxy-1, 4-naphthoquinone by spectroscopic analyses. 
  Reference    Z. Naturforsch. 55b, 667—669 (2000); received March 28 2000 
  Published    2000 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0667.pdf 
 Identifier    ZNB-2000-55b-0667 
 Volume    55 
104Author    Maciej Kubickia, Teresa Borowiak2, WieslawZ. AntkowiakbRequires cookie*
 Title    The Effect of Different Hydrogen Bonding Schemes on Melting Points of Two Isomeric 2-Hydroxy-bornane-3-carboxylic Acids  
 Abstract    The crystal structures of two isomeric compounds, 2-^n^/o-hydroxybornane-3-enüfo-carb-oxylic acid and 2 -ex0 -hydroxybomane-3 -£ndo-carboxylic acid, have been determined by X-ray single crystal analysis. The only difference between these two compounds is the disposition of the 2-hydroxy group with respect to the bomane skeleton. Both compounds show quite different hydrogen bonding schemes. In the endo-hydroxy-erafo-carboxy isomer there is one intramolecular and one intermolecular hydrogen bond, which connects molecules into infinite chains, while in the £xo-hydroxy-£/2docarboxy isomer there are two intermolecular hydrogen bonds that form a more stable architecture of two kinds of chains which interconnect to close rings comprising four molecules. Due to these differences the melting point of 2 is ca. 30° higher than for 1 . 
  Reference    Z. Naturforsch. 55b, 671—676 (2000); received March 16 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0671 
 Volume    55 
105Author    Maciej Kubicki3, Teresa Borowiak3, WieslawZ. AntkowiakbRequires cookie*
 Title    Hydrogen Bonds in "Carboxyoximes": the Case of Bomane Derivatives  
 Abstract    The tendency of forming mixed carboxyl-to-oxime hydrogen bonds was tested on the series of bomane derivatives: one with the acid function only (bomane-2-erajfo-carboxylic acid), one with the oxime function (2,2'-diethylthiobomane-3-oxime), and one with both oxime and carboxylic functions (bomane-2-oxime-3-endo-carboxylic acid). The crystal structures of these compounds were determined by means of X-ray diffraction. In bomane-2-^n^/o-carboxylic acid and 2,2'-diethylthiobom ane-3-oxime 'homogenic' hydrogen bonds were found, and these hydrogen bonds close eight-and six-membered rings, respectively. By contrast, in bomane-2-oxime-3-era/o-carboxylic acid 'heterogenic' hydrogen bonds between carboxylic and oxime bonds were found. This carboxylic-oxime, or 'carboxyoxime' system is almost always present in compounds which have both oxime and carboxylic groups; therefore it can be regarded as an element of supramolecular structures (synthon). The presence of such synthons can break the tendency of carboxylic acids and oximes towards crystallizing in centrosymmetric structures. 
  Reference    Z. Naturforsch. 55b, 677—684 (2000); received March 16 2000 
  Published    2000 
  Keywords    Bom ane Derivatives, Hydrogen Bonds, Supramolecular Synthons 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0677.pdf 
 Identifier    ZNB-2000-55b-0677 
 Volume    55 
106Author    Hidenari Inoue3, Shuichi Narino3, Naoki Yoshioka3, Ekkehard FluckbRequires cookie*
 Title    Thermal Decomposition of Prussian Blue Analogues of the Type Fe[Fe(CN)5NO]  
 Abstract    The structure and properties o f the thermal decomposition products of Fe[Fe(CN)sNO] • x H2O (x = 5 ~ 6) have been studied by M össbauer and FT-IR spectroscopy, X-ray diffraction, and conductivity measurements. The valence state and coordination environment of the iron ions change dramatically when the nitrosyl ligand is eliminated by heat-treatment under vacuum at 200 °C. The dark blue product obtained by heat-treatment under vacuum at 250 °C is characteristic of the mixed-valence state in Prussian blue analogues. The electrical conductivity of the dark blue product is higher by a factor o f 103 than that o f the starting material because of the mixed-valence state between Fe(III)[Fe(II)(CN)5] and Fe(II)[Fe(III)(CN)5]. Heat-treatment under vacuum at 350°C yields a new product Fe(II)[Fe(II)(CN)4] the crystal structure of which is different from that of the starting material. The electrical conductivity of the decomposition product obtained at 350 °C is about 105 times higher than that of the starting material. 
  Reference    Z. Naturforsch. 55b, 685—690 (2000); received April 5 2000 
  Published    2000 
  Keywords    Prussian Blue Analogues, Mixed-Valence State, Thermal Decomposition 
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 Identifier    ZNB-2000-55b-0685 
 Volume    55 
107Author    B. Lorenzen, W. PreetzRequires cookie*
 Title    Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von /raws-(Et4N)[OsF4Cl2] Crystal Structure, Vibrational Spectra and Normal Coordinate Analysis of frans-(Et4N)[OsF4Cl2]  
 Abstract    frans-Tetrafluorodichloroosmate(V), Normal Coordinate Analysis By careful oxidation of ?ra«5 -tetrafluorodichloroosmate(IV) with P b 0 2/trifluoroacetic acid in dichloromethane the corresponding osmium(V) complex anion rran5 -[OsF4Cl2]_ is for­ med. The X-ray structure determination on a single crystal has been performed of trans-(Et4N)[OsF4Cl2] (triclinic, space group P i, a = 7.190(5), b = 7.205(5), c = 7.732(5) Ä, a = 71.28(1), ß = 71.32(1), 7 = 70.76(1)°, Z = 1). Based on the molecular parameters of the X-ray determination the IR and Raman spectra of the complex have been assigned by normal coordi­ nate analysis. The valence force constants are: fd(OsCl) = 2.13 and fd(OsF) = 3.81 mdyn/A. 
  Reference    Z. Naturforsch. 55b, 691—694 (2000); eingegangen am 2. Mai 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0691 
 Volume    55 
108Author    C. Rumpf, W. BenschRequires cookie*
 Title    Synthesis and Crystal Structure of New Ternary Chalcogenides of Group IV Metals: K2ZrS4, Rb2ZrS4, and Rb2HfS4  
 Abstract    The new ternary one-dimensional chain compounds K2ZrS4 , Rb2ZrS4 and Rb2HfS4 were prepared at 350 °C by reacting A2S3 and S with elemental M (A = K, Rb; M = Zr, Hf). They are isostructural, crystallizing in the orthorhombic space group Pbca with Z = 8 . The M atoms are in a distorted octahedral environment of four S2_ anions and one S22~ unit. The structure consists of infinite anionic chains comprised of edge-sharing M S6 octahedra running parallel to the [001] direction separated by the alkali metal cations. The composition of the chain may be formulated as j-,[MS4/ 2 (S2)2 -]. The two crystallographically independent alkali cations are in eight-and ninefold coordination of S atoms. 
  Reference    Z. Naturforsch. 55b, 695—698 (2000); received Mai 2 2000 
  Published    2000 
  Keywords    Polychalcogenides, Zirconium, Hafnium 
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 Identifier    ZNB-2000-55b-0695 
 Volume    55 
109Author    Matthias WeilRequires cookie*
 Title    The Crystal Structures and Thermal Behaviour of the Mercury Arsenates Hg2(H2A s0 4)2, Hg2As20 6 and HgAs20 6  
 Abstract    Thermal Behaviour, Mercury, Arsenates Crystals of Hg2(H2As0 4)2, which are isotypic with the corresponding dihydrogenphosphate Hg2(H2PÜ4)2, were obtained from a concentrated arsenic acid solution. The crystal structure (P2,/n, a = 6.1838(4), b = 15.0987(9), c = 4.7989(3) A , ß = 91.977(1)°, Z = 2, R = 0.045 for 1318 structure factors, 56 variables) contains a H gj+ dumbbell with a distance d(Hg-Hg) = 2.5040(10) A and a symmetrical coordination of four oxygen atoms for each mercury atom. The oxygen atoms also belong to tetrahedral dihydrogenarsenate groups F ^A sO ^, which stabilize the structure by hydrogen bonding. On heating Hg2(H2A s0 4) 2 condenses to give the mercury(I) metaarsenate Hg2As2 0 ö. Crystals of that compound were obtained under hydrothermal con­ ditions at 165 °C starting from elemental mercury in 60 wt% aqueous H 3 ASO4 . The crystal structure (P31m, a = 4.8411(2), c = 7.5961(9) A, Z = 1, R = 0.037 for 376 structure factors, 13 variables) may be represented by sheets of edge sharing [AsOö] octahedra and layers of Hg2+ dumbbells, which alternate along the c axis. The dumbbells show a distance d(Hg-Hg) = 2.5190(10j A and are coordinated symmetrically by six oxygen atoms at a distance d(Hg-O) = 2.374(4) A. They are positioned above and below the vacant sites of adjacent [As2 0 ö]~-lay­ ers. On further heating Hg2As2 0 ö disproportionates into elemental mercury and mercury(II) metaarsenate, HgAs2 0 ö. Single crystals of HgAs2 0 ö were grown via chemical vapor transport from microcrystalline HgAs2 0 6 with H gCh as transport agent, using a temperature gradient of 650 550 °C. HgAs20 6 (P31m, a = 4.8482(2), c = 4.9789(10) Ä, Z = 1, R = 0.031 for 367 structure factors, 12 variables) crystallizes in the PbSb2 0 ö structure type, where anionic [Sb20 6]2' layers have the same arrangement. The divalent mercury atomsohave a pseudoocta-hedral environment of oxygen atoms with a distance d(Hg-O) = 2.353(3) A. I n tro d u c tio n 
  Reference    Z. Naturforsch. 55b, 699—706 (2000); received April 25 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0699 
 Volume    55 
110Author    Herrn Prof, M. Dr, SchmidtRequires cookie*
 Title    Hydrido(acylenolato)cobalt(III)-Verbindungen mit Trimethylphosphan- Liganden: Insertionsreaktionen mit Alkinen und die ersten Carbonylcobalt(III)-Komplexe  
 Abstract    H y d rid o (a c y le n o la to)c o b a lt(III) C o m p o u n d s C o n tain in g T rim eth y lp h o sp h an e L ig an d s: In sertio n R e a c tio n s w ith A lk y n es and th e F irst C a rb o n y lco b alt(III) C o m p lex es H an s-F rie d rich K lein 3, X iao y a n L ia, U lrich F lö rk eb u n d H an s-Jü rg en H a u p tb Hydridocobalt(III) Complexes, Insertion of Alkynes, Regioselectivity Formal insertion of phenylethyne into Co-H functions of mer-octahedral acyl(enolato)-cobalt(III) hydrides 1 -3 proceeds under ambient conditions affording ^'-vinylcobalt(III) compounds where the dianionic acyl(enolato) ligands are derived from 2-formyl-4-phenyl-cyclohexanone (4), l-formyl-cyclohexan-2-one (5), and 3-hydroxo-2,3-diphenyl-propenal (6). Dissociation and association of trimethylphosphane results in a reversible transformation of penta-coordinate complexes 4 -6 into hexa-coordinate ones 7 -9, respectively, involving dif­ ferent tautomeric vinyl species. In toluene solution 9 rearranges by reductive C,C coupling into a 5,6-772-olefin(enolato)cobalt(I) complex 10. Trimethylsilylethyne undergoes a hydrolytic desilylation reaction which is followed by reductive C,C-coupling reactions of acyl and vinyl functions selectively producing chelating r/-enolato-5,6-?;2-olefin ligands in cobalt(I) com ­ pounds 13 -1 6 where the (ax,eq)chelating ligands are derived from l-formyl-cyclohexan-2-one (13), 3-hydroxo-2,3-diphenyl-propenal (14), 2-formyl-a-tetralone (15), and 2-formyl-4-tert-butyl-cyclohexanone (16). An axial position of the enolato-0 donor in the trigonal bipyramidal configuration of complex 15 has been confirmed by X-ray diffraction analysis. With 1,4-bis(trimethylsilyl)buta-diyne 1,2-addition in cobalt(III) hydrides 2, 3, 11 (as deriverd from 2-form yl-a-tetralone), and 12 (as derived from 2-formyl-4-tert-butyl-cyclohexanone) produces 2-metalated vinyl groups in compounds 17 -20. Dissociation of trimethylphosphane from 17 and 19 does not activate C,C coupling at the cobalt(III) centre of penta-coordinate 21 and 22. Steric congestion in compounds 17, 18, and 20 favours exchange of trimethylphosphine for carbon monoxide affording the first octahedral carbonyl complexes of cobalt (d) (23 -25). In the crystal and in solution a meridional configuration is adopted by complex 23 with the CO group in a position opposite to the acyl function. 
  Reference    Z. Naturforsch. 55b, 707—717 (2000); eingegangen am 27. April 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0707 
 Volume    55 
111Author    Rolf Minkwitz, Michael BerkeiRequires cookie*
 Title    Spektroskopische Charakterisierung und Kristallstruktur von Trifluormethyliod(III)-bis(trifluoracetat) CF3I(OCOCF3 )2 Spectroscopic Characterisation and Crystal Structure of Trifluoromethyliodine(III) Bis-trifluoroacetate, CF3I(OCOCF3)2  
 Abstract    Iodine(III) Trifluoromethyliodine(III) bis-trifluoracetate [CF3I(OCOCF3)2] was obtained by reaction between CF3IF2 and (CH3)3SiOCOCF3 at -5 0 °C. It crystallises in the triclinic space group P i with a = 520.8(1), b = 1042.9(1), c = 1087.5(1) pm, a = 65.22(0)°, ß = 81.18(0)°, 7 = 80.09(0)°, and two formula units per unit cell. The compound has also been characterised by its Raman and IR spectra. 
  Reference    Z. Naturforsch. 55b, 718—722 (2000); eingegangen am 13. April 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0718 
 Volume    55 
112Author    Dieter Sellmann, Daniel Häußinger, Torsten Gottschalk-Gaudig, FrankW. HeinemannRequires cookie*
 Title    Übergangsmetallkomplexe Activated CH2 Groups, and Interionic Interactions in the Solid State ('pybuS4'2-= 2,6-Bis(2-mercapto-3,5-di-terf-butylphenylthio)dimethylpyridine(2-))  
 Abstract    mit Schwefelliganden, 145 [1]. [Ru(NO)(,py^M S4 ,)]Br, ein Komplex mit [Ru(NO)(NS4)]-Gerüst, aktivierten CH2-Gruppen und interionischen Wechselwirkungen im Festkörper ['p y ^ S ^ 2* = 2,6-Bis(2-mercapto-3,5-di-terM>utyl-phenylthio)dimethylpyridin(2-)] Transition Metal Complexes with Sulfur Ligands, 145 [1]. [Ru(NO)('pybuS4')]Br, a Complex with [Ru(NO)(NS4)] Core, In the search for soluble and reactive ruthenium nitrosyl complexes, [Ru(NO)('pybuS4')]Br ([2]Br) was synthesized by template alkylation of NBu4[Ru(NO)('buS2')2] with py(CH',Br)2 ['pybuS4'2-= 2,6-bis(2-mercapto-3,5-di-ter/-butyl-phenylthio)dimethylpyridine(2-); '°US2 = 2-mercapto-3,5-di-terf-butylphenylthiolate(2-); py(CH2Br)2 = 2,6-bis(bromomethyl)pyridine]. The solid state structure of 2 has been determined by X-ray diffraction, which reveals a head-to-head 0 -0 interaction between the linear Ru-NO entities. The ligand CH 2 protons of [2]+ are activated and exchange with D+ under ambient conditions. The /^(NO) band of [2]Br appears at 1841 cm -1 in the solid state (KBr or hostaflon mull) and is significantly blue-shifted in solution (1879 cm-1 in MeOH, 1886 cm -1 in DMF). A similar blue-shift (1866 cm -1 in KBr vs. 1888 cm -1 in MeOH) has been found for [Ru(NO)('pyS4')lBr ([l]B r) which contains the parent [Ru(NO)('pyS4')]+ cation ['pyS4'2-= 2,6-bis(2-mercaptophenylthio)dimethylpyr-idine(2-)]. These t^(NO) shifts can be explained either by an interionic charge-transfer between the bromide anions and the nitrosyl complex cation or by 0 -0 interactions between two NO ligands as found for solid-state [2]Br. These interactions are not found for [l]O Ts which exhibits a ^(N O) band at ca. 1890 cm -in the solid state (KBr, hostaflon) as well as in MeOH solution. 
  Reference    Z. Naturforsch. 55b, 723—729 (2000); eingegangen am 5. April 2000 
  Published    2000 
  Keywords    Ruthenium Nitrosyl Complexes, Sulfur Ligands, Interionic Interaction 
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 Identifier    ZNB-2000-55b-0723 
 Volume    55 
113Author    Sabine Rings3, Vladislav Ischenkob, Martin Jansenb, Sonderdruckanforderungen An, ProfM. JansenRequires cookie*
 Title    Darstellung und Strukturanalyse von Lithium- [tetrakis-(methylamino-)aluminat] Preparation and Crystal Structure of Lithium[tetrakis-(methylamino-)aluminate]  
 Abstract    The preparation and spectroscopic data of the new ternary amide LiAl(NHCH3)4 are reported. The structure of the title compound has been determined from X-ray powder diffraction data (tetragonal, 14,, a = 14.000(4) A, c = 9.275(2) A, 210 reflections, R = 3.75%, weighted R = 5.10%). Both the lithium and the aluminium atoms are coordinated tetrahedrally by nitrogen atoms. Edge-sharing pairs of lithium centered and aluminium centered tetrahedra are connected to each other in helical chains forming a 3D-framework via the remaining vertices. A comparison of the projection of the crystal structure of LiAl(NHCH3)4 along the c-axis to those of cristobalite and of hollandite, (Ba,K)2 (M n,Fe)80 16, reveals similarities with respect to both the connectivity and the topology of ring structures. 
  Reference    Z. Naturforsch. 55b, 730—734 (2000); eingegangen am 20. April 2000 
  Published    2000 
  Keywords    Amides, Lithium, Aluminium 
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 Identifier    ZNB-2000-55b-0730 
 Volume    55 
114Author    Fritz Preuss, Frank TabellionRequires cookie*
 Title    ^BuN=V[P(SiMe3)2]3 : Das erste Beispiel eines stabilen Phosphanidovanadium(V)-Komplexes 'BuN=V[P(SiMe3)2]3: The First Example of a Stable Phosphanidovanadium(V) Complex  
 Abstract    Phosphanidovanadium(V) Complex The synthesis of the first stable phosphanidovanadium(V) complex rBuN=V[P(SiMe3) 2 ]3 is described. The compound has been investigated by 'H, C ,31P, 'V NMR spectroscopy. The results indicate an eighteen-electron complex. 
  Reference    Z. Naturforsch. 55b, 735—737 (2000); eingegangen am 21. März 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0735 
 Volume    55 
115Author    Requires cookie*
 Title    Polysulfonylamine, CXXVI [1] Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Ein robustes Achtring-Synthon in Koexistenz mit einem dritten Wasserstoffbrückenmotiv - Cyclodimere, Ketten, supramolekulare Bindungsisomere und ein fünffach verwobenes dreidimensionales (C-H ***0)-Netzwerk  
  Reference    Z. Naturforsch. 55b, 738 (2000) 
  Published    2000 
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 Identifier    ZNB-2000-55b-0738 
 Volume    55 
116Author    Polysulfonylam, G. JonesRequires cookie*
 Title    Polysulfonylamine, CXXVII [1] Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Ein robustes Achtring-Synthon als Bestandteil dreidimensionaler Wasserstoffbrückenmuster  
 Abstract    ines, C X X V II [1] H ydrogen B onding in Crystalline O nium D im esylam ides: A R obust E ight-M em bered R ing Synthon as a C om ponent in T hree-D im ensional H yd ro g en Bonding P atterns K a m a W ijaya, O liver M oers, D agm ar H enschel, A rm and B laschette und P e te r D i(m ethanesulfonyl)am ide, Onium Cation, Synthon Robustness In order to study crystal packings and hydrogen bonding frameworks, low-temperature X-ray structures were determined for three onium salts of general formula B H +(M e S 0 2)2N _, where B H + is acetamidinium (1, monoclinic, space group F2\lc, Z = 4), guanidinium (2, monoclinic, P 2xlc, Z = 4), or 4,6-diamino-2-thioxo-2,3-dihydropyrimidinium (3, monoclinic F l xln, Z = 4). In every case the ions create three-dimensional N -H ---N / 0 networks, in which all N -H donors of the cations and four (in 1) or five (2, 3) acceptors of the anion are involved; non-conventional secondary bonds, e.g. C-H-O/N, do not play an important role in the packings. For the isotypic structures 1 and 2, congruencies and dissimilarities of the hydrogen bonding patterns are discussed in detail. D espite the structural and chemical diffe­ rences betw een the cations and the way in which they are attached to the anion, each of the three structures displays a robust eight-membered ring synthon [N2 = R2(8), antidromic] constructed via two-centre hydrogen bonds from a syn, s_y/i-sequence H -N -C (s p 2) -N -H of the respective cation and a V-shaped 0 -S (s p 3) -N fragment of the anion. Although the networks in 2 and 3 contain several N -H (-0) 2 three-centre interactions, the two-point connectivity of the synthon is distinctly preserved. The results indicate that the (M e S 0 2)2N~ ion may be utilized in crystal engineering as a dependable building block. 
  Reference    Z. Naturforsch. 55b, 753—7 (2000); eingegangen am 23. März 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0753 
 Volume    55 
117Author    M. Artin, Jansen, Thom As Jäschke, Sonderdruckanforderung An, ProfM. Dr, JansenRequires cookie*
 Title    Kristallstruktur und spektroskopische Charakterisierung von Hexamethyl- disilazan-Aluminiumtrichlorid [(H3C)3Si]2NH * AICI3 Crystal Structure and Spectroscopic C haracterisation of H exam ethyl- disilazane-trichloroalum inum [(H 3 C )3Si]2N H * AICI3  
 Abstract    Silazane, Aluminate By reaction of hexamethyldisilazane with alu­ minium trichloride in hexane hexamethyldisila-zane-trichloroaluminum [(H3C)3Si]2NH • A1C13 is formed. The adduct has been characterized by MS, IR, Raman, *H, 13C, 27Al, 29Si N M R spectroscopy, and by a crystal structure determination (1425 independent reflections, R = 0.035). The space group is Pbca with a = 1312,6(5), b = 1182,9(5), c = 1964,7(5) pm; Z = 8. [(H 3C)3Si]2N H • A1C13 forms monomeric units which have point sym m e­ try Ci and exhibit an A l-N bond length of 193,9(3) pm. 
  Reference    Z. Naturforsch. 55b, 763—7 (2000); eingegangen am 5. April 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0763_n 
 Volume    55 
118Author    Z. NaturforschRequires cookie*
 Title    9/?^28-Lactonization of Pomonic Acid from Lantana camara roots  
 Abstract    Lantana camara L. var. aculeata, Verbenaceae, Pomonic Acid Lantana camara L. var. aculeata yielded a triterpenoid, pomonic acid (1). The acid-catalyzed lactonization o f this y-hydroxy acid afforded a re­ arranged lactone 3, the structure of which was as­ signed by detailed 2D-NM R studies. A reaction mechanism involving a 1,3-butadiene intermedi­ ate is proposed. 
  Reference    Z. Naturforsch. 55b, 768—7 (2000); received March 24 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0768_n 
 Volume    55 
119Author    Hans Bock, Erik Heigel, Norbert NagelRequires cookie*
 Title    Interaction in Molecular Crystals, 156 [1, 2]. Crystal Growth and Structure Determination of Alkali(imidodiphosphate) Salts with Cations of Low and High Coordination Numbers  
 Abstract    Lipophilically Wrapped Polylithium-and Polyrubidium-Ionclusters, Imidodiphosphate Ligands Imidodiphosphates ^N[PO(OR)2]2 and Imidodiphosphonates ^N[POR2]2 are effective che­ lating ligands for a variety of metal cations including even Na®, for which a lipophilically wrapped hexameric polyion cluster has been structurally characterized. The corresponding he-xameric lithium and polyrubidium ion complexes reported here exhibit considerable structural differences: The rather small Li* cations of coordination number five and tetraphenylimido-diphosphate form an isolated hexameric aggregate analogous to the Na® one, whereas the larger Rb^ with coordination number seven and (3,4-dimethylphenyl)substituents crystallizes as a chain polymer. Based on the crystal structures, the dominant Coulomb attractions bet­ ween cations and anions, the spatial requirement of the ligands and the essential phenyl/phenyl interactions in their lipophilic skin are discussed. Wechselwirkungen in Molekülkristallen, 156 [1, 2]. 
  Reference    Z. Naturforsch. 55b, 773—784 (2000); eingegangen am 15. Mai 2000 
  Published    2000 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0773.pdf 
 Identifier    ZNB-2000-55b-0773 
 Volume    55 
120Author    Hans Bock, Erik HeigelRequires cookie*
 Title    Wechselwirkungen in Molekülkristallen  
 Abstract    , 157 [1, 2]. Mischkristallzüchtung und Strukturbestimmungen von Tetra(3,4-dimethylphenyl)-imidodiphosphat-Salzen mit Alkalikation-Verhältnissen K®/Rb®(l:5) und Rb®/Cs®(l:l) Interaction in Molecular Crystals, 157 [1, 2]. Mixed Crystal Growth and Structure Determinations of Tetrakis(3,4-dimethylphenyl)-imidodiphosphate Salts with Alkali Cation Ratios K®/Rb® (1:5) and Rb®/Cs® (1:1) Lipophilically Wrapped Polyion-Clusters, Imidodiphosphate Ligands, Phenyl/phenyl Interaction Mixed crystals of tetrakis(3,4-dimethylphenyl)imidodiphosphate salts with alkalication ratios K "/R bT (1:5) and R tr/C s* (1:1), (1:3) as well as (3:1) have been grown by suspending finely ground stoichiometric mixtures of alkali carbonates in toluene solutions of the strongly chelating ligand HN(PO(OR)2)2-The cation ratios were measured by Total Reflexion X-Ray Fluorescence (TXRF) analysis and the single crystal structures of the polymeric K+/Rb* as well as the Rb*/Cs® imidodiphosphate salts determined by X-ray structure analysis. The selectivity of the various alkali ions for insertion in the crystal lattices of the individual imidodiphosphate salts has been confirmed by concentration-dependent crystallizations and discussed based on the structural analysis of the differing ligand conformations. The unit cell parameter dependence on the alkali cation radii provided information on van der Waals interactions between adjacent phenyl rings of the imidodiphosphate ligands and suggests the selective alkali cation insertion to be partly due to supramolecular repulsion within the lipophilic phenyl skin during the self­ aggregation of the polymeric salt chains. 
  Reference    Z. Naturforsch. 55b, 785—795 (2000); eingegangen am 15. Mai 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0785 
 Volume    55 
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