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1995[X]
41Author    F.-D Martin, Hk Miiller-BuschbaumRequires cookie*
 Title    Ein Beitrag zur Kristallchemie der Alkali-Erdalkalimetall-Oxovanadate: Synthese und Struktur von K3CaV50 15 A Contribution to the Crystal Chemistry of A lkaline-Alkaline-Earth Oxovanadates: Synthesis and Structure of K3CaV50 15  
 Abstract    Single crystals of K3CaV50 15 have been prepared by crystallization from melts. The com ­ pound shows a new structure type with orthorhombic symmetry, space group D ^-C m m a, a = 25.953(5), b = 15.688(3), c = 7.804(4) Ä , Z = 8. Typical features of K3CaV50 15 are isolated cyclic V40 12 and V60 18 groups o f corner sharing V 0 4 tetrahedra. 
  Reference    Z. Naturforsch. 50b, 243 (1995); eingegangen am 13. Septem ber 1994 
  Published    1995 
  Keywords    Potassium, Calcium, Vanadium Oxide, Crystal Structure 
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 Identifier    ZNB-1995-50b-0243 
 Volume    50 
42Author    H. Szillat, Hk Müller-BuschbaumRequires cookie*
 Title    Synthesis and Crystal Structure of (Cu,Zn)3 7 5 Mo30 12  
 Abstract    Single crystals of (Cu,Zn)3 75Mo30 12 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. (Cu,Zn)3 75Mo3Oi2 crystallizes orthorhom-bically, space group D^-P212,21, Z = 4, a = 17.947(9), b = 5.092(3), c = 10.685(5) A. It is isotypic to Cu385Mo30 12. All molybdenum atoms are tetrahedrally coordinated by oxygen atoms. There are layers of C u 0 6 and Z n 0 6 octahedra, while other metal sites are occupied by copper in a deformed prismatic coordination with one oxygen atom at a remarkably greater distance from copper than the other five. Some of the zinc atoms occupy positions in chains of face-sharing octahedra with an occupancy factor of 0.75. The crystal structure is discussed with respect to the isotypic compound Cu385Mo30 12 and compounds of the type CuLnMo20 8. 
  Reference    Z. Naturforsch. 50b, 247—251 (1995); eingegangen am 13. September 1994 
  Published    1995 
  Keywords    Crystal Structure, Copper, Molybdenum, Zinc, Oxide 
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 Identifier    ZNB-1995-50b-0247 
 Volume    50 
43Author    H. Szillat, Hk Müller-BuschbaumRequires cookie*
 Title    Uber das Oxomolybdat AgKCu3Mo4Oi6 mit Silber in siebenfacher Koordination About the Oxomolybdate AgKCu3Mo4O i6 with Silver in Seven-Fold Coordination  
 Abstract    Single crystals of AgKCu3Mo40 16 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. This compound crystallizes with monoclinic symmetry, space group C |h-P 2 Je, a = 5.056(1), b = 14.546(4), c = 19.858(9) Ä, ß = 86.64(5)°, Z = 4. The crystal structure of AgKCu3Mo40 16 is closely related to K2Cu3Mo40 16 showing ribbons of edge-sharing C u 0 6 and AgÖ7 polyhedra. The ribbons are linked by tetrahedrally coordinated molybdenum and K2O 10 groups. Another kind of M o 0 4 tetrahedra occupies the cavities inside the ribbons. The crystal structure and the coordination of silver, copper, potas­ sium and molybdenum by oxygen are discussed with respect to K2Cu3Mo40 16. 
  Reference    Z. Naturforsch. 50b, 252—256 (1995); eingegangen am 19. September 1994 
  Published    1995 
  Keywords    Crystal Structure, Copper, Silver, Molybdenum, Potassium 
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 Identifier    ZNB-1995-50b-0252 
 Volume    50 
44Author    H. Szillat, Hk Müller-BuschbaumRequires cookie*
 Title    Zur Kristallchemie eines neuen Oxomolybdats: Cu2YbMo30 12 On the Crystal Chemistry of a New Molybdenum Oxide: Cu2YbM o30 12  
 Abstract    Single crystals of Cu2YbMo30 12 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. Cu2YbMo30 12 crystallizes with monoclinic symmetry (space group C 2h -P 12i/m l, a = 5.162(2), b = 10.885(4), c = 8.699(4) A. ß -95.73(7)°, Z = 2), forming a new structure type. Typical features are layers of C u 0 6 octahedra, connected via corners and edges. These layers are linked by molybdenum and ytterbium ions along [001]. The crystal structure as well as the coordination of copper, ytterbium and molybdenum and the oxidation states of copper and molybdenum are discussed with respect to the related but not isotypic compound (Cu,Zn)3 75Mo30 12. 
  Reference    Z. Naturforsch. 50b, 257—260 (1995); eingegangen am 19. September 1994 
  Published    1995 
  Keywords    Crystal Structure, Copper, Molybdenum, Ytterbium, Oxide 
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 Identifier    ZNB-1995-50b-0257 
 Volume    50 
45Author    H. Szillat, Hk Müller-BuschbaumRequires cookie*
 Title    Synthese und Kristallstruktur eines Oxoantimonats mit Verwandtschaft zum Delafossit-Typ: Cu3MgSbl940 6 Synthesis and Crystal Structure of an Oxoantimonate with Relationship to the Delafossite Type: Cu3MgSbi 40 6  
 Abstract    Single crystals of Cu3MgSb140 6 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. Cu^MgSb] 40 6 crystallizes trigonally, space group C 3v — R3/c, a = 5.348(1), c = 34.482(8) A, Z = 6, with a Delafossite related new structure, characterized by layers containing S b 0 6 and M g06 octahedra. These layers are connected by O -C u -O dumb-bells. The crystal structure is discussed with respect to the Delafossite type. 
  Reference    Z. Naturforsch. 50b, 261—264 (1995); eingegangen am 26. September 1994 
  Published    1995 
  Keywords    Crystal Structure, Copper, Magnesium, Antimony, Oxide 
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 Identifier    ZNB-1995-50b-0261 
 Volume    50 
46Author    Requires cookie*
 Title    Metallkomplexe mit biologisch wichtigen Liganden, LXXV [1] Synthese metallorganischer Cobalt(III)-, Iridium(III)-und Ruthenium(II)-Komplexe mit a-Iminocarboxylat-Liganden  
  Reference    Z. Naturforsch. 50b, 265 (1995) 
  Published    1995 
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 Identifier    ZNB-1995-50b-0265 
 Volume    50 
47Author    Kay Severin, Wolfgang BeckRequires cookie*
 Title    Metallkomplexe mit biologisch wichtigen Liganden, LXXVII [1] Synthese und Reaktionen von Dihydrido-Iridium(III)-Komplexen mit a-Aminocarboxylat-Liganden Metal Complexes of Biologically Im portant Ligands, LXXVII [1] Synthesis and Reactions of Dihydrido-Iridium (III) Complexes of a-A m ino Carboxylates  
 Abstract    Dihydrido-iridium(III) complexes of the general formula IrH2(aa)(PPh3)2 (aa = L-ala-ninate, L-valinate, L-prolinate and L-phenylalaninate, 1 -4) have been synthesized. Reac­ tions of 1 -3 with phenylacetylene give the hydrido-di(phenylethynyl) complex IrH(C=CPh)2(PPh3)3 (5). The latter compound is also formed from IrH3(PPh3)3 and phenyl­ acetylene. All complexes have been characterized by NMR ('H, 13C, 31P) and IR spectro­ scopy. 
  Reference    Z. Naturforsch. 50b, 275—279 (1995); eingegangen am 10. Oktober 1994 
  Published    1995 
  Keywords    Iridium, a-Amino Acids, Dihydrido Complexes, Phenylethynyl Complex 
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 Identifier    ZNB-1995-50b-0275 
 Volume    50 
48Author    M. Sekar, K. J. Rajendra, PrasadRequires cookie*
 Title    Synthesis of Novel Oxazolo(4,5-a)carbazoles  
 Abstract    l-Hydroxyimino-l,2,3,4-tetrahydrocarbazoles, a-Acetoxy Imine, Oxazolo(4,5-a)carbazole 
  Reference    Z. Naturforsch. 50b, 280—282 (1995); received February 14 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0280 
 Volume    50 
49Author    G. Abriele Wagner, Uwe Verfürth, Rudolf HerrmRequires cookie*
 Title    Chemistry of Fenchonesulfonic Acid Derivatives  
 Abstract    Fenchonesulfonic Acid, Wagner-Meerwein Rearrangement, Fenchonesulfonyloxaziridine, Enantioselective Oxidation (1 5)-(+)-Fenchone is sulfonated by S 0 3 or H2S 0 4/acetic anhydride in the bridgehead methyl group. This could be confirmed by NMR techniques (INADEQUATE). The fenchonesulfonic acid obtained is converted (SOCl2/NH3) to the cyclic fenchonesulfonimide, which can be oxidized to the corresponding oxaziridine, in close analogy to 10-camphorsul-fonimide. Improved procedures for this reaction sequences are given. During the treatment of the sulfonic acid with thionyl chloride, a byproduct with a rearranged bicyclic skeleton is observed whose structure has been determined by ozonolytic degradation and NMR tech­ niques. A possible mechanism for this rearrangement is suggested, based on MNDO calcu­ lations of the intermediate carbocations. The fenchonesulfonyloxaziridine oxidizes sulfides to chiral sulfoxides with appreciable enantiomeric excess, but very low reaction rate. A com­ parison with camphor-derived oxaziridines having similar steric requirements is made. 
  Reference    Z. Naturforsch. 50b, 283—288 (1995); received September 23 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0283 
 Volume    50 
50Author    HansH. Karsch, Fritz Bienlein, Maximilian Heckei, Oliver Steigeimann, Klaus Burger, Jörg CyrenerRequires cookie*
 Title    Trifluormethyl-substituierte Germanium-Heterocyclen durch [4+l]-Cycloaddition Trifluoromethyl Substituted Germ anium Heterocycles via [4+1] Cycloaddition Reactions  
 Abstract    4,4-Bis(trifluoromethyl)-l,3-diazabuta-l,3-dienes, 2,2-Dichloro-3,3-bis(trifluoromethyl)-2,3-dihydro-1 H-l,4,2-diazagermoles, 5-Fluoro-4-trifluoromethylimidazoles Formation of partially fluorinated imidazoles 6 from 4,4-bis(trifluoromethyl)-l,3-diaza-buta-l,3-dienes 1 in the presence of low-valent metal compounds is shown to proceed via a [4+1] cycloadduct in the case of germanium(II)-chloride. The resulting germole 3 has been characterized by X-ray analysis. The five-membered ring is planar and the germanium atom adopts tetrahedral configuration. 
  Reference    Z. Naturforsch. 50b, 289—293 (1995); eingegangen am 11. August 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0289 
 Volume    50 
51Author    Najam-Ul-Hussain Syed, ZaheerA. Kazmia, Abdul Hm Ed3, Malik3, Nighat Afzab, Wolfgang Voelterc, H.E JRequires cookie*
 Title    A Regioselective One Pot Synthesis and Synthetic Applications of Cyanodeoxy Sugars by Cyanotrimethylsilane [1]  
 Abstract    , Cyanotrimethylsilane The regioselective epoxide opening of different 2,3-anhydropyranoses by cyanotrimethyl­ silane is investigated. The isolated cyanodeoxy pyranoses allow easy access to the correspond­ ing branched-chains aminomethyl sugars by lithium aluminium hydride reduction or sugar amides by controlled acid hydrolysis. 
  Reference    Z. Naturforsch. 50b, 294—302 (1995); received June 28 1994 
  Published    1995 
  Keywords    Anhydro Sugars, Cyanodeoxy Sugars, Epoxy Ring Opening, Branched Chain Pyranoses 
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 Identifier    ZNB-1995-50b-0294 
 Volume    50 
52Author    MatthiasW. Haenel3, Udo-Burckhard Richter3, Sonja Solarb, Nikola GetoffbRequires cookie*
 Title    Radiation-Induced C -C Bond Cleavage in 1,2-Diarylethanes as Model Compounds of Coal, Part 3 Pulse and Steady-State Radiolysis of l,2-Di(9-anthryl)ethane in Organic Solvents [1, 2]  
 Abstract    Radiolysis, C -C Bond Cleavage, 1,2-Diarylethane, Aluminium Hydride Reagent, Transient Spectroscopy l,2-Di(9-anthryl)ethane (1,2-DAE) was used as a model for coal to study the C -C bond cleavage of the ethano linkage in the radiolysis of solutions containing NaAlH2(OCH2CH2OCH3)2 [NaAlH2(OR)2]. Transient species were investigated by pulse radiolysis of solutions of 1,2-DAE in THF, DME and toluene in the absence and the presence of NaAlH2(OR)2. In the presence of NaAlH2(OR)2 stabilized, long-lived radical anion/so­ dium cation pairs of 1,2-DAE were generated even in the non-polar solvent toluene. The reaction mechanisms differ substantially for solutions in the ether solvents (THF or DME) and for solutions in toluene. Steady-state radiolysis (60Co y-rays) of solutions of 1,2-DAE in toluene containing NaAlH2(OR)2 resulted in the C -C bond cleavage of the ethano linkage. This is attributed to the unstable dianion (1,2-DAE2 -, 2 Na+) formed in two successive radi­ ation-induced reductions via (1,2-DAE' , Na+). The resulting (9-anthryl)methyl carbanionic fragments Ci4H9CH2~, Na+ react with A lH(OR)2 generated in the process, to form the alum-inate salts [C14H9CH2AlH (O R)2_, Na+]. From the aluminate salts, 9-methylanthracene (9-MA) was obtained by hydrolysis in yields up to 65 wt.%. 
  Reference    Z. Naturforsch. 50b, 303—311 (1995); received September 15 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0303 
 Volume    50 
53Author    José Barluenga, R. Oberto Sanz, FranciscoJ. FañanásRequires cookie*
 Title      
 Abstract    Regioselective Cross Coupling, Propargylamine-Zirconocene Complex, Zirconacyclopentene N-(2-bromoallyl)-N-methylaniline 1 is easily converted into the propargylamine-zircono-cene complex 3 via loss of m ethane from 2-[zirconocene(methyl)]allyl amine 2. Regioselec­ tive insertion reactions with alkenes and benzophenone afford, after iodinolysis, products 4 -10. 
  Reference    Z. Naturforsch. 50b, 312—314 (1995); received Septem ber 26. 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0312 
 Volume    50 
54Author    Thomas Schmidt, Stephan Neis, Richard GoddardRequires cookie*
 Title    Synthesis, Structure, and Properties of Homoleptic l-Oxa-l,3-diene Molybdenum and Tungsten Complexes  
 Abstract    Homoleptic tris(l-oxa-l,3-diene)m olybdenum and tungsten complexes are formed as yel­ low, crystalline compounds in 54-80% isolated yield on treatm ent of the corresponding /3-unsubstituted a,/3-unsaturated ketones with W (CO)3(CH 3CH 2CN)3 or (y6-C6H 6)M o(CO)3 in refluxing hexane. Reaction of these oxadienes with (^6-C6H 5CH3)2Mo in tetrahydrofuran or /7-hexane provides a new high yield route to homoleptic molybdenum complexes that are otherwise difficult to prepare. X-ray crystal structure analyses of two air-stable, isomeric tungsten complexes reveal a significant contribution of a cr2,?/2-bonding mode in the coordi­ nated oxadiene moieties. U nder reaction conditions that allow the platinum catalyzed hydro­ genation of phenyl substituents in these ligands, the coordinated oxadiene fragments are inert, thus demonstrating an unprecedented chemoselectivity in the hydrogenation of aryl-substituted enones. On the other hand, the complexes are labile enough to catalyze the cyclotrimerization of alkynes such as methyl propiolate. 
  Reference    Z. Naturforsch. 50b, 315—325 (1995); received September 7 1994 
  Published    1995 
  Keywords    Oxadiene Complex, Molybdenum, Tungsten, X-Ray, Selective Hydrogenation 
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 Identifier    ZNB-1995-50b-0315 
 Volume    50 
55Author    Fiirstner, DenisN. Jumbam, Nongyuan ShiRequires cookie*
 Title    Alois  
 Abstract    Low-valent titanium prepared by the reduction of TiCl3 with zinc dust oxidatively adds to a-ketoam ides or a-ketoesters with the formation of the corresponding titanium enediolates. These 1,2-difunctional nucleophiles, which have hardly been used in organic synthesis so far, undergo regioselective intramolecular aldol condensation reactions with various electrophiles such as aldehydes, ketones, nitriles, esters and amides. This methodology allows the synthesis of differently substituted coumarin and 2-quinolone derivatives. 
  Reference    Z. Naturforsch. 50b, 326—332 (1995); received September 13 1994 
  Published    1995 
  Keywords    Low-Valent Titanium, Enediolates, Coumarins, 2-Quinolones, Aldol Condensation 
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 Identifier    ZNB-1995-50b-0326 
 Volume    50 
56Author    H. Bönnemann, W. Brijoux, J. Richter, R. Becker, J. Hormes, J. R. OtheRequires cookie*
 Title    The Preparation of Colloidal Pt/Rh Alloys Stabilized by NR4+-and PR4+-Groups and their Characterization by X-Ray-Absorption Spectroscopy  
 Abstract    Nanometallic Organosols, Alloy Colloids of Pt/Rh, Catalysis Bimetallic Pt/Rh colloids protected by N R 4+-or PR4+ groups are accessible by the co­ reduction of PtCl2 and RhC l3 using hydrotriorganoborates in organic media. According to TEM the particle size ranges from 1.9 to 2.5 nm. EDX point analysis of several samples has shown that both metals are present in the particles. The metallic character of the Pt/Rh core confirmed by XANES, and EXAFS data clearly indicate the formation of nanometallic al­ loys. Colloidal Pt/Rh alloys prepared in this way are very soluble and highly stable in organic phases and serve as sources for heterogeneous hydrogenation catalysts. 
  Reference    Z. Naturforsch. 50b, 333—338 (1995); received September 9 1994 
  Published    1995 
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 Identifier    ZNB-1995-50b-0333 
 Volume    50 
57Author    WolfJürgen RichterRequires cookie*
 Title    Asymmetrische Synthesen durch Substitution: Diastereomere Arsinite aus homochiral substituierten Arsoniten Asymmetrie Synthesis via Substitution: D iastereom eric Arsinites from Homochirally Substituted Arsonites  
 Abstract    Conceptually novel access to chiral arsinites is provided by reacting phenyl-0,0-dim enthyl-arsonite (1) with bulky nucleophiles e. g. terr-butyl-lithium or wo-propyl-lithium to yield the arsinites 3 and 4. The asymmetric induction determined by GC and NM R is 50% and 30% d.e. A small nucleophile effects double substitution. 
  Reference    Z. Naturforsch. 50b, 339—341 (1995); eingegangen am 15. September 1994 
  Published    1995 
  Keywords    Asymmetrie Induction, Chiral Arsonites, Arsinites 
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 Identifier    ZNB-1995-50b-0339 
 Volume    50 
58Author    JohnJ. Eisch, Xian Shi, Jacek LasotaRequires cookie*
 Title    Carbon-Carbon Bond Formation by Reductive Coupling with Titanium(II) Chloride Bis(tetrahydrofuran)  
 Abstract    bis(tetrahydrofuran) 1, generated by the treatm ent of TiCl4 in TH F with two equivalents of n-butyllithium at -7 8 °C, has been found to form carbon-carbon bonds with a variety of organic substrates by reductive coupling. Diphenylacetylene is dimerized to ex­ clusively (E,E)-1,2,3,4-tetraphenyl-l,3-butadiene; benzyl bromide and 9-bromofluorene give their coupled products, bibenzyl and 9,9'-bifluorenyl, as do benzal chloride and benzotrichlo-ride yield the l,2-dichloro-l,2-diphenylethanes and l,l,2,2-tetrachloro-l,2-diphenylethane, respectively. Styrene oxide and and ris-stilbene oxide undergo deoxygenation to styrene and fra/«-stilbene, while benzyl alcohol and benzopinacol are coupled to bibenzyl and to a mix­ ture of tetraphenylethylene and 1,1,2,2-tetraphenylethane. Both aliphatic and aromatic ke­ tones are smoothly reductively coupled to a mixture of pinacols and/or olefins in varying proportions. By a choice of experimental conditions either the pinacol or the olefin could be made the predom inant product in certain cases. The reaction has been carried out with heptanal, cyclohexanone, benzonitrile, benzaldehyde, furfural, acetophenone, benzophenone and 9-fluorenone. In a remarkable, multiple reductive coupling, benzoyl chloride is converted into 2,3,4,5-tetraphenylfuran in almost 50% yield. The stereochemical course of two such couplings, that of diphenylacetylene to yield exclusively (E,E)-1,2,3,4-tetraphenyl-l,3-buta­ diene and that of acetophenone to produce only racem/c-2,3-diphenyl-2,3-butanediol, is inter­ preted to conclude that the couplings proceed via two electron transfer pathways (TET) involving titanium (IV) cyclic intermediates of the titanirene and the oxatitanacyclopropane type, respectively. 
  Reference    Z. Naturforsch. 50b, 342—350 (1995) 
  Published    1995 
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 Identifier    ZNB-1995-50b-0342 
 Volume    50 
59Author    Joachim Bruckmann, Carl Krüger, Frank LutzRequires cookie*
 Title    Systematic Structural Investigations on Phosphines  
 Abstract    This work contributes to the systematic investigation of phosphines. In an attem pt to deter­ mine the nature, shape, volume and direction of the lone pairs at the phosphorus atoms in phosphines, high resolution X-ray structure analyses of triphenylphosphine, tris(p-methoxy-phenyl)phosphine, bis(2,4,6-triisopropylphenyl)phosphine, 1,1 -bis(diphenylphosphino)ethene and 4,5,6-triphenyl-4-phosphaspiro[2.4]hept-5-en have been carried out. New valence force field param eters (TRIPOS force field) are presented which were developed on the basis of the molecular structures of the free phosphines. The results of crystal growing experiments using zone melting techniques are summarized. 
  Reference    Z. Naturforsch. 50b, 351—360 (1995); received Septem ber 20 1994 
  Published    1995 
  Keywords    Phosphines, Molecular Modeling, Crystal Growing, High Resolution X-Ray Analysis 
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 TEI-XML for    default:Reihe_B/50/ZNB-1995-50b-0351.pdf 
 Identifier    ZNB-1995-50b-0351 
 Volume    50 
60Author    GuyC. Lloyd-Jones, Andreas PfaltzRequires cookie*
 Title    Synthesis and Structures of Low-Valent Tungsten Complexes Bearing Chiral Oxazoline-Derived Ligands  
 Abstract    The synthesis of low-valent tungsten (0 and II) complexes bearing chiral bidentate phos-phino-oxazoline or bisoxazoline ligands is described. The structures of four of the complexes have been determined by single crystal X-ray analyses. Tungsten(II)-allyl complexes of the type [W(CO)2(PN)(C3H 5)Cl] (PN = phosphino-oxazoline) are fluxional in solution, but can be crystallized as single diastereoisomers. The complex [W (CO)3(PN)(CH 3CN)], which also crystallizes as a single diastereoisomer, is readily oxidized in solution and solid state, in stark contrast to analogous compounds bearing four carbonyl ligands [W(CO)4(PN)] or [W(CO)4(NN)] (NN = bisoxazoline) which were found to be stable. [W (CO)3(PN)(CH 3CN)] functions as a highly enantioselective catalyst in allylic substitution reactions with dimethyl sodiomalonate, whereas complexes of the type [W (CO)2(P N)(Z -C 3H 4)X)] (Z = H, Ph; X = Cl, Br) failed to yield allylic alkylation products. 
  Reference    Z. Naturforsch. 50b, 361—367 (1995); received Septem ber 26 1994 
  Published    1995 
  Keywords    Chiral Tungsten Complexes, Phosphino-oxazoline Ligands, Bisoxazoline Ligands, Tungsten Allyl Complexes, Asymmetric Catalysis 
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 TEI-XML for    default:Reihe_B/50/ZNB-1995-50b-0361.pdf 
 Identifier    ZNB-1995-50b-0361 
 Volume    50 
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