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2000 (185)
41Author    F. Leßmann, L. Beyer, K.-H Hallmeier, R. Richter, J. Sieler, R. Strauch, A. VoigtRequires cookie*
 Title    Vierzähnige Benzamidin-Liganden in ein-und mehrkemigen Kupfer(II)-Komplexen Quadridentate Benzamidine Ligands in Mono-and Oligonuclear Copper(II) Complexes  
 Abstract    Bridged N-thiocarbamoyl substituted bis-benzamidines (C2H5)2N-C(S)-N=C(Ph)-NH-R-NH-C(Ph)=N-C(S)-N(C2H5)2 with different moieties R (H2L : R = diphenylmethane-2,2'-diyl, H2 L2: R = diphenylmethane-3,3'-diyl, and H2 L3: R = diphenylmethane-4,4'-diyl) were synthe­ sized by the reaction of N-(thiocarbamoyl)benzimidoyl chlorides with diamines. These quadri­ dentate ligands form neutral mononuclear (CuL1), dinuclear (Cu2L32) and trinuclear (Cu3 L2 3) copper(II) chelates in dependence of the different bridging unit in the ligands. The compounds were characterized by NMR, IR, EPR and XPS spectroscopy and FAB mass spectrometry. The molecular structures of the ligand H2L3 and the complex CuL1 have been determined by X-ray methods. 
  Reference    Z. Naturforsch. 55b, 253—261 (2000); eingegangen am 26. November 1999 
  Published    2000 
  Keywords    Benzamidines, Copper Chelates, EPR, ESCA 
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 Identifier    ZNB-2000-55b-0253 
 Volume    55 
42Author    VladimirA. Ovchynnikov3, TarasP. Timoshenko3, VladimirM. Amirkhanov3, Joachim Sielerb, ViktorV. Skopenko3Requires cookie*
 Title    Coordination Compounds of Lanthanide Nitrates with Dimorpholido-N-trichloroacetylphosphorylamide. The Structure of Di(dimorpholido-N-trichloroacetylphosphorylamide)- diaqua Neodymium(III)trinitrate  
 Abstract    Lanthanide, Carbacylamidophosphate The coordination compounds of the general formula Ln(N0 3)3(HL)2(H2 0)2 H2 0 , where Ln = La, Ce -Nd, Sm -Dy, HL = CCl3C(0)NHP(0)[N(CH2CH2)20]2, dimorpholido-N-tri-chloroacetylphosphorylamide, have been synthesized. The complexes were studied by IR, 1H and31P NMR and UV-VIS absorption spectroscopies. X-ray diffraction analyses indicate that all synthesized compounds are isostructural. The crystal structure of NdtNO^M HLM I^Oh-FbO was solved (monoclinic, a = 11.0467(3), b = 15.9080(5), c = 24.1921(7) A, ß = 96.4080(10)°, space group P2i/n, V = 4224.7(2) A3, Z = 4, R = 0.049, wR = 0.0915). The complex has a molecular structure. The monodentate neutral phosphorictriamide ligands are coordinated to the metal atom via the phosphoryl oxygen atom. The coordination polyhedron of Nd is a sphenocorona; C.N. = 10 (6 0 [N 0 3~], 20[HL], 20[H 20]). It was shown that these compounds in methanol solution are 1:1 electrolytes, and in acetone solution weak electrolytes. According to NMR data in acetone solution the complexes of the lanthanides with the ligand {HL} have axial symmetry. 
  Reference    Z. Naturforsch. 55b, 262—268 (2000); received September 7 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0262 
 Volume    55 
43Author    Z. NaturforschRequires cookie*
 Title    Dedicated to Professor Othmar Stelzer on the occasion of his 60th birthday  
 Abstract    NMR Data, Boron, Fluorine Cs[(CF3)3BNH2] reacts with CF3NO to form cesium ?ran5-trifluoromethyldiazenido-tris(tri-fluoromethyl)borate Cs[(CF3)3BN=NCF3] (2), the structure of which has been investigated by single-crystal X-ray diffraction. The diazene nature of the anion is confirmed by the length of the N=N bond, 1.231(6) A, and the size of the N-N-B angle, 115.5(4)° -the B-N bond length being 1.559(7) A. Compound 2 is hitherto the first diazenidoborate which has been fully characterized. 
  Reference    Z. Naturforsch. 55b, 269—272 (2000); received December 13 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0269 
 Volume    55 
44Author    Z. NaturforschRequires cookie*
 Title      
 Abstract    Bismuth Chalcogenide Halides The crystal structure of Bi3Se4Br has been determined. With respect to its (Bi,Se) substructure it is related to orthorhombic Bi^Ses and to Bii9S27Br3. 
  Reference    Z. Naturforsch. 55b, 273—276 (2000); received December 12 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0273 
 Volume    55 
45Author    M. Akoto Kurihara3, TakujiK. Aw Ashim A3, K. Azuhiko, O. Zutsum IbRequires cookie*
 Title    Complexation of Cobalt(II), Nickel(II), and Copper(II) Ions with Pyridine, 2-Methylpyridine, 3-Methylpyridine, and 4-Methylpyridine in Acetonitrile  
 Abstract    Thermodynamics of Complexation, Divalent Transition Metal Ions, Pyridine and its Methyl Derivatives, Acetonitrile, Calorimetry and Spectrophotometry Thermodynamic data of the complexation of cobalt(II), nickel(II), and copper(II) ions with pyridine (py), 2-methylpyridine (2Me-py), 3-methylpyridine (3Me-py), and 4-methylpyridine (4Me-py) have been determined by calorimetry and spectrophotometry in acetonitrile (MeCN) containing 0.1 mol dm-3 (C2H5)4NC104 as a constant ionic medium at 25 °C. The calorimetric and spectrophotometric data for py, 3Me-py, and 4Me-py revealed the formation of [ML]2+, [ML2]2+, [ML3]2+, and [ML4]2+ (M = Co2+, Ni2+, Cu2+; L = py, SMe-py, 4Me-py). For 2Me-py, on the other hand, the formation of only one complex, [M(2Me-py)]"+ (M = Co2+, Ni2+), was detected. The stepwise thermodynamic quantities and the individual electronic spectra of the complexes suggest that all of these have a six-coordinate octahedral structure. The stability of the [M(2Me-py)]2+ (M = Co2+, Ni2+) complexes is much lower than that of the corresponding py, 3Me-py, and 4Me-py complexes. The difference in the stability of the 2Me-py complexes is mainly due to their unfavorable entropy changes because the differences of enthalpies for all the complexes are not so significant. The free energies for the formation of the mono complexes follow the order Mn(II) > Co(II) > Ni(II) > Cu(II) < Zn(II) for the py, 3Me-py, and 4Me-py systems. The AH°{ values vary in the same order and the A S ^ values are similar. Hence, the stability difference of the mono complexes originates from the enthalpic term. 
  Reference    Z. Naturforsch. 55b, 277—284 (2000); received November 18 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0277 
 Volume    55 
46Author    É. Lida Bonfada3, Ernesto Schulz-Lang3, R. Enato, A. Ndré, Z. An3, U. Lrich, A. BramRequires cookie*
 Title    Syntheses and Structures of Thorium(IV) Complexes with Bis(diphenylphosphino)ethane Dioxide, Ph2P(0)CH2CH2P(0)Ph2, and Bis(diphenylphosphoryl)amide, [Ph2P(0)N P(0)P h2]  
 Abstract    Thorium Complexes, Phosphine Oxides, Bis(diphenylphosphoryl)amide The cationic thorium(IV) complexes [Th{Ph2P(0)CH2CH2P(0)Ph2}2(N0 3)3]N03 and [Th{Ph2P(0)NP(0)Ph2}3(dmso)2]N03 have been synthesized by reactions of Th(N03)4 • 5H2O with bis(diphenylphosphino)ethane dioxide, Ph2P(0)CH2CH2P(0)Ph2 (L1), or ammo­ nium bis(diphenylphosphoryl)amide, (NH4)[Ph2P(0)NP(0)Ph2] (NH4L2), and subsequent re­ crystallization from dimethyl sulfoxide. The products have been studied spectroscopically and by X-ray crystallography. The thorium atom is ten-co-ordinate in the [Th(L')2(N0 3)3]+ cation with a coordination sphere which does not match one of the idealized polyhedra for ten-coordination. Th-O bonds have been found in the range between 2.342(3) (phosphine oxide) and 2.599(4) A (nitrate). An eight-coordinate thorium atom is found in the [Th(L2)3(dmso)2]+ cation. The almost ideal square-antiprismatic environment of the metal is occupied by oxygen atoms with T h-0 bond lengths between 2.363(6) and 2.392(11) Ä. 
  Reference    Z. Naturforsch. 55b, 285—290 (2000); received December 13 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0285 
 Volume    55 
47Author    IgorV. Zatovsky3, NikolayS. Slobodyanik3, DenisA. Stratiychuk3, KonstantinV. Domasevitch3, Joachim Sielerb, EduardB. RusanovcRequires cookie*
 Title    A Novel Convenient Synthesis of Mixed-Valence Tini/TiIV Double Phosphates Starting with Titanium Nitride TiN  
 Abstract    A new synthetic approach for the low-and mixed-valence double titanium phosphates starting with titanium nitride, TiN, and based on the controlled oxidation of a low-valent metal in the phosphate melt is presented. The reaction of the system M '20 -P2O5 -TiN (M1 = Na, K) in air (800-1050 °C) leads to loss of nitrogen, N2, and results in the formation of a number of double phosphates: KTiP20 7, K2TiniTiIV(P0 4)3, K T i0P 04, NaTiP20 7, NaTi2(P O ^ and a new mixed-valent diphosphate, NaTimTiIV(P20 7)2. The mixed-valent species K2Ti nTi (P0 4)3 and NaTimTiIV(P207)2 were characterized by single crystal X-ray diffraction. The described synthetic procedure is proposed as a simple and convenient method for the preparation of low-and mixed-valent phosphate materials. 
  Reference    Z. Naturforsch. 55b, 291—298 (2000); received November 22 1999 
  Published    2000 
  Keywords    Melted Systems, Titanium, Double Phosphates, Mixed-valent Compounds, X-Ray Data 
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 Identifier    ZNB-2000-55b-0291 
 Volume    55 
48Author    Requires cookie*
 Title    Polysulfonylamine  
 Abstract    , CXXV [1]. Neue Komplexe von Disulfonylaminen mit Kronenethern -im voraus entworfen oder zufällig entdeckt Polysulfonylam ines, CX X V [1]. New Com plexes of D isulfonylam ines with Crow n E th ers -Preconceived or D iscovered by Serendipity D agm ar H enschel, K am a W ijaya, O liver M oers, A rm and B laschette und P eter G. Jones Institut für A n organ isch e und A n alytisch e C h em ie der T echnischen U niversität, Postfach 3329, D -38023 B raunschw eig Sonderdruckanforderungen an Prof. Dr. A . B lasch ette oder Prof. Dr. P. G. Jones. Fax: (+49) 5313915387. E-mail: p.jones@ tu-bs.de Z. Naturforsch. 55b, 2 9 9 -3 1 6 (2000); received N o v em b er 22, 1999 Supram olecular D esign , H ydrogen B ond ing, D isu lfon ylam in es In a study aim ed at the "d econ stru ction " o f the su pram olecular aggregate 3 (1 8C 6) -2 H N (S 0 2M e)2 (1, 18C6 = 18-crow n-6), w hich is know n to display a ladder structure with tw o isotactic [ 1 8 C 6 -M e S 0 2N (H) S 0 2M e---)o c polym ers form ing the uprights and sym m etrically N-H-O bonded 18C6 rings providing the rungs, the follow in g crystalline com p lexes were 
  Reference    Z. Naturforsch. 55b, 299 (2000) 
  Published    2000 
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 Identifier    ZNB-2000-55b-0299 
 Volume    55 
49Author    Z. NaturforschRequires cookie*
 Title    An Expeditious Approach to Trisubstituted Chiral Tetrahydrofurans  
 Abstract    F azila Iq b a l3, M o h a m m e d Saleh S h e k h a n i3*, A b d u l M a lik 3 *, M a so o d P a rv e z b, U z m a R ia z 3, Z u lfiq a r A li3, an d K halid M o h a m m e d K h a n 3 Ozonolysis of 3,6-anhydro-4-0-(/?-toluenesulphonyl)-D-glucal (9), obtained in four steps from D-glucose, provided the target compound 11. The structure and configurations of 9 and 11 have been determined by spectral studies and X-ray crystallography. Similar strategy with D-galactose provided the corresponding derivatives 10 and 12, respectively. 
  Reference    Z. Naturforsch. 55b, 317—320 (2000); received September 20 1999 
  Published    2000 
  Keywords    Chiral Tetrahydrofurans, Asymmetric Synthesis, D-Glucose, D-Galactose 
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 Identifier    ZNB-2000-55b-0317 
 Volume    55 
50Author    Ib Ra, H. Im, S.A H AfizRequires cookie*
 Title    /7-Enaminonitriles in Heterocyclic Synthesis: Synthesis of New 1,4-Dihydro- pyridine, PyrazoIo[l,5-a]pyrimidine, Aminothiophene and Pyridine Derivatives  
 Abstract    /3-Enaminonitriles, Aminothiophene, Pyrazolopyrimidine Utility of 3-aminocinnamonitrile (1) in the synthesis of new 1,4-dihydropyridine, pyrazolo-[l,5-a]pyrimidine, aminothiophene and pyridine derivatives is reported. 
  Reference    Z. Naturforsch. 55b, 321—325 (2000); received December 20 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0321 
 Volume    55 
51Author    E.Requires cookie*
 Title    Extraktionen von Ginsenosiden aus Ginseng-Wurzeln mit flüssigem Ammoniak, Methanol-Wasser oder Wasser  
 Abstract    x tra c tio n s o f G in se n o sid e s fro m G in se n g R o o ts w ith L iq u id A m m o n ia , M e th a n o l-W a te r o r W a te r In -H o C ho, E b e r h a r d H o h a u s, A x el L e h n e n an d H a rro L en tz Malonyl-ginsenosides, Ginsenosides, HPLC Extractions of ginsenosides from ginseng roots with liquid ammonia, methanol/w ater (60:40; v/v) or water were carried out. The extracts have been analyzed qualitatively and quantitatively to valuate yield and selectivity of extractions of ginsenosides. W ater supplied the lowest yield. The yields of extracts with liquid ammonia were higher than those with m ethanol-water (60%). Yields of the ginsenosides Rbj, Rb2, Rc and Rd by extracting with liquid ammonia are about twice as much as those of the extraction with methanol-w ater (60%). It was proved by HPLC that malonyl-ginsenosides m -R bl5 m-Rb2, m-Rc and m-Rd were converted to the corresponding neutral ginsenosides by extraction with liquid ammonia. Because of high yields of extracts and simultaneous increase of the contents of Rb], R b2, Rc and Rd the extraction with liquid ammonia is obviously superior to the other extraction methods. Furtherm ore, ginsenosides from ginseng roots were extracted by alkaline methanol-w ater (60%) solutions. Alternatively, the extracts of the methanol-water (60%) extraction were treated with sodium hydroxide solution. Both methods convert also the malonyl-ginsenosides to neutral ginsenosides. 
  Reference    Z. Naturforsch. 55b, 326—332 (2000); eingegangen am 7. Dezember 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0326 
 Volume    55 
52Author    Sonderdruckanforderungen An, ProfE V DehmlowRequires cookie*
 Title    Uber die Isolierung von Sitosterin-(6'-0-acyl)-/?-D  
 Abstract    glucopyranosiden aus Flacourtia indica und über unerwartete Gelbildungen durch das Triacetat O n th e Iso la tio n o f S ito ste rin -(6 '-0 -a c y l)-p -D -g lu c o p y ra n o sid e s from Flacourtia indica an d on U n e x p e c te d F o rm a tio n o f G e ls by th e T riac eta te E c k e h a rd V o lk er D e h m lo w a, M a tth ia s G u n te n h ö n e ra u n d Teunis van R e e b A mixture of the title co m p o u n d -(ö ') stearate, margarate, palmitate, linolate, and 
  Reference    Z. Naturforsch. 55b, 333—335 (2000); eingegangen am 27. Dezember 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0333 
 Volume    55 
53Author    M. Ath, O. S. EngeRequires cookie*
 Title    A Conformational Study of 5,10,15,20-Tetraalkyl-22//+,24//+-porphyrindiium Salts (Dication Salts)  
 Abstract    N-protonation of 5,10,15,20-tetraalkylporphyrins with n-butyl, isobutyl, isopropyl, 1-ethyl-propyl or ferf-butyl substituents yields the respective 22,24-dihydroporphyrins (22//+,24//+-porphyrindiium salts) that exhibit highly nonplanar conformations. Depending on the steric demand of the meso substituents, the free base porphyrins have planar to moderately ruffled macrocycles (primary or secondary alkyl residues) or are severely ruffled (tertiary alkyl resi­ dues). X-ray crystallographic studies show that protonation of porphyrins with «-Bu (2), i-Pr (3) or EtPr (4) substituents leads to steric congestion of the core resulting in symmetric, saddle distorted macrocycles as evidenced by average displacements of the Cb positions from the mean plane ranging from 0.79 to 1.01 A. The structures observed for these porphyrin diacids are very similar in distortion mode and degree of nonplanarity to 5,10,15,20-tetraaryl-22f/+,24//+-porphyrindiium salts and to 2,3,7,8,12,13,17,18-octaalkyl-5,10,15,20-tetraaryl-porphyrins. In contrast, protonation of the highly ruffled 5,10,15,20-tetrakis(teA-r-butyl)porph-yrin results in a switch of the conformational distortion mode. The dication 6 shows both saddle distortion (Cb displacements -1.3 A) and ruffling of the macrocycle (Cm displacements of approx. 0.48 A). Thus, the need to accomodate four N-H units in the porphyrin core with its associated out-of-plane tilting of the pyrrole rings and the steric strain induced at the meso carbon atoms results in a highly nonplanar porphyrin with mixed distortion modes. 
  Reference    Z. Naturforsch. 55b, 336—344 (2000); received January 20 2000 
  Published    2000 
  Keywords    Porphyrins, Steric Strain, Porphyrin Dications, Crystal Structure, Conformational Analysis, 22, 24-Dihydroporphyrins 
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 Identifier    ZNB-2000-55b-0336 
 Volume    55 
54Author    S.Requires cookie*
 Title    Synthese und Kristallstruktur von 2,4-B is(m ethyIam ino)-2-pentenium - chlorid [1]  
 Abstract    ynthesis an d C rystal S tru c tu re o f 2,4-B is(m e th y la m in o)-2 -p e n te n iu m C h lo rid e [1] N o rb e rt K u h n 3, Jo a n n a F ah l3, S tefan F u c h s3 u n d G e ra ld H e n k e l5 The vinamidinium chloride C7H I5N2C1 (5) is obtained from the corresponding vinamidine C7H i4N2 (4) and HC1; the X-ray structure reveals a polymeric nature consisting of w-shaped cations connected with the chloride ions by hydrogen bonds. D e riv a te des V in am id in s [2] k ö n n e n als W-, U 
  Reference    Z. Naturforsch. 55b, 345—346 (2000); eingegangen am 16. Dezember 1999 
  Published    2000 
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 Identifier    ZNB-2000-55b-0345_n 
 Volume    55 
55Author    GeraldL. Wegner, Alexander Jockisch, Annette Schier, Hubert SchmidbaurRequires cookie*
 Title    Crystal and Molecular Structures of the Sulfurization and Selenation Products of Bis[bis(trimethylsilyl)amino]germanium(II). Crystal Structure of (Triphenylphosphine)gold(I) Bis(trimethylsilyl)amide  
 Abstract    Germylenes, Germanium(II) Amides, Sulfurization Treatment of bis[bis(trimethylsilyl)amino]germanium(II) with elemental sulfur or sele­ nium affords high yields of the corresponding monosulfide [(Me.^Si^NLGeS and selenide [(M e.^SihN^GeSe, respectively. The crystalline products have now been shown to be cyclic dimers with (GeS/Se)2 four-membered rings by X-ray single crystal structure analysis. The crystal structure of (triphenylphosphine)gold(I) bis(trimethylsilyl)amide (Ph;?P)Au-N(SiMe3)2 has also been determined. The molecule is a monomer with a tricoordinate nitrogen atom in a planar configuration [SiiNAu]. The compound does not undergo insertion of the bis[bis(trimethylsilyl)amino]germylene. 
  Reference    Z. Naturforsch. 55b, 347—351 (2000); received March 8 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0347 
 Volume    55 
56Author    Bettina Eichhorn, Heinrich NöthRequires cookie*
 Title    New Diazasilaphosphetidines and their Precursors  
 Abstract    A series of aminosilanes (R 'H N bSiR : have been prepared. In case of bulky substituents R' the aminolysis of Ph^SiCb stops at the (R'HN)ClSiPh2 stage. Replacement of the Cl atom is achieved with LiNHR' which allows the synthesis o f mixed bisaminosilanes (R'HN)(R"HN)SiPh2. The X-ray structures of three of these compounds have been determined. There are no intermolecular N-H -N hydrogen bonds in these compounds in the solid state. Several 1,3,2,4-diazaphosphetidines have been synthesized using bis(N-lithioamino)silanes and bis(N-lithioamino)phosphanes . Amongst these the heterocycle 18 possesses an almost planar four membered N iSiP ring system. 
  Reference    Z. Naturforsch. 55b, 352—360 (2000); received January 18 2000 
  Published    2000 
  Keywords    Bis(monoorganylamino)diorganylsilanes, 1, 3, 2, 4-Diazasilaphosphetinides 
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 Identifier    ZNB-2000-55b-0352 
 Volume    55 
57Author    Raija Oilunkaniemia, RistoS. Laitinen3, Markku AhlgrénbRequires cookie*
 Title    The Solid State Conformation of Diaryl Ditellurides and Diselenides: The Crystal and Molecular Structures of (E = O, S; E' = Te, Se)  
 Abstract    The crystal and molecular structures of dithienyl ditelluride (C^FLS^Tei (1), difuryl ditelluride (C ^fL O hT ei (2), dithienyl diselenide (CUfLShSei (3), and difuryl diselenide (GiILO hSeT (4) are reported in this paper and compared to those of other simple diaryl ditel­ lurides and diselenides. The chalcogen-chajcogen bonds exhibit approximately single bond lengths [Te-Te = 2.7337(8) and 2.7240(4) Ä in 1 and 2, respectively; Se-Se = 2.357(1) and 2.368(2) A in 3 and 4, respectively], as do the chalcogen-carbon bond lengths [Te-C = 2.095(9) -2.104(6) in 1 and 2.091(6) -2.105(9) A in 2; Se-C = 1.87(1) -1.90(1) A in 3 and 1.887(8) -1.897(10) A in 4]. The aromatic rings are disordered. The dihedral angles C-E-E-C range from 79(2) to 96(1)° are consistent with the concept of minimized p lone-pair repulsion of adjacent chalcogen atoms. The dependence of molecular parameters on the angle between the aromatic rings and the chalcogen-chalcogen bonds follow trends established previously for aromatic disulfides. Though the bond parameters and conformations of 1 -4 are similar, the packing of the molecules is different. The two ditellurides 1 and 2 show short Te -Te contacts (3.900 -4.002 Ä in 1 and 4.060 -4.172 A in 2). The two diselenides 3 and 4 do not exhibit close chalcogen-chalcogen interactions. The NMR spectroscopic properties of 1 -4 are discussed. 
  Reference    Z. Naturforsch. 55b, 361—368 (2000); received January 21 2000 
  Published    2000 
  Keywords    Furyl Ditelluride, Thienyl Diselenide, Furyl Diselenide 
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 Identifier    ZNB-2000-55b-0361 
 Volume    55 
58Author    Henri Brunner, Peter SchmidtRequires cookie*
 Title    Asymmetrische Katalyse, 134 [1]. Naproxen-Derivate durch enantioselektive Decarboxylierung Asymmetric Catalysis, 134 [1]. Naproxen Derivatives by Enantioselective Decarboxylation  
 Abstract    Naproxen, Asymmetrie Catalysis, Enantioselective Decarboxylation, Cinchona Alkaloids 2-Aryl-substituted propionic acids, such as the important anti-inflammatory agent Naproxen, exist in two enantiomeric forms. The (S^-enantiomer of 2-(6-methoxynaphth-2-yl)propionic acid 1 is about 28 times more effective than the (/?)-enantiomer. A new catalytic method to synthesize Naproxen (S)-l involves the enantioselective decarboxylation of suitably substi­ tuted malonic acid derivatives. Thus, 2-(6-methoxynaphth-2-yl)-2-methylmalonic acid 6 and its monoester 7 were stirred in THF with catalytic amounts of chiral bases, which induced decarboxylation. After work-up, optical inductions up to 39.8% ee were found in the resulting products 1 and 9. The optically active bases may be fully recycled by extraction. 
  Reference    Z. Naturforsch. 55b, 369—372 (2000); eingegangen am 28. Februar 2000 
  Published    2000 
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 Identifier    ZNB-2000-55b-0369 
 Volume    55 
59Author    AndreyB. Lysenko3, O. Leg, V. Shishkin, R. Ostislav, D. LamRequires cookie*
 Title    Synthesis and Structure of a Palladium(II) Chloride Complex with 2-(2-Methyl-3-phenyl-isoxazolidin-5-yl)-pyridine  
 Abstract    Isoxazolidines, Palladium(II) Complexes, IR Data The 1:1 complex of palladium(II) chloride with 2-(2-methyl-3-phenyl-isoxazolidin-5-yl)-pyridine (L) has been prepared and studied by means of elemental analysis, 1H NMR spec­ troscopy and X-ray diffraction (monoclinic, space group P2i/n with parameters: a = 8.141(2), b = 9.750(2),c = 20.691(6)A ,ß = 95.62(3)°,V = 1634.4(7)A ,Z = 4 ;R 1= 0.054andwR2= 0.144 for 3352 unique reflections). A square-planar coordination polyhedron has been established for the palladium atom both in acetone solution and in the solid state. The organic ligand is coor­ dinated toometal in a bidentate manner via nitrogen atoms of the pyridine substituent (Pd-N(2) 2.125(3) A) and the isoxazolidine heterocycle (Pd-N(l) 2.102(3) A). The other two coordina­ tion positions of palladium are occupied by chlorine atoms (Pd-Cl(l) 2.321(1) and Pd-Cl(2) 2.333(1) Ä). The six-membered chelate ring formed by Pd, N(2), C(4), C (l), 0(1) and N (l) possesses a "twist-tub" conformation. The isoxazolidine cycle has an envelope conformation with an equatorial orientation of the methyl group. 
  Reference    Z. Naturforsch. 55b, 373—376 (2000); received December 22 1999 
  Published    2000 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0373.pdf 
 Identifier    ZNB-2000-55b-0373 
 Volume    55 
60Author    Thom As, M. Klapötke, B. Urkhard, K. Rum, Kurt Polbom, C. Laudia, M. R. IenäckerRequires cookie*
 Title    Synthesis and Characterization of Bromo-and Bromochloroplumbates(II). Crystal Structures of [Ph4E]2[Pb3Br8] (E = P, As) and [Ph4P][PbBrCl2] * CH3CN  
 Abstract    Tetraphenylphosphonium(arsonium) Octabromotriplumbate, Tetraphenylphosphonium Bro-modichloroplumbate, Quantum Chemical Calculations [PhiPMPb^Brg] and [PhuAshtPb^Brg] crystallize both in the monoclinic space group Po2\ln. The lattice parameters of [PluPMPb^Brg] are a = 14.637(7), b = 8.151(3), c = 23.388(8) Ä, ß = 106.02(3)°, Z = 2 and of [PluAsMPbsBrg] are a = 14.697(7), b = 8.219(3), c = 23.527(8) A, ß = 106.27(3)°, Z = 2. The lattice parameters of [PhuPHPbBrClilCH^CN, which crystallizes in the triclinic space group (P I), are a = 9.435(3), b = 10.2577(14), c = 14.055(2) Ä, a = 88.320(11)°, ß = 84.82(2)°, 7 = 84.19(2)°, Z = 2. 207Pb NMR shifts of halogenoplumbates in solution are reported. 
  Reference    Z. Naturforsch. 55b, 377—382 (2000); received January 18 2000 
  Published    2000 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0377.pdf 
 Identifier    ZNB-2000-55b-0377 
 Volume    55 
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