Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    ISSN: 1434-1948
    Keywords: Lead(1+) ; Indium(3+) ; Organylphosphanylamide complexes ; Phosphazene ; 207Pb-NMR spectra ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of PbCl2 with LiN(PPh2)2 (1) at -78°C affords the P-P coupled phosphazene Ph2P-N=PPh2-PPh2=N-PPh2 (2) as an oxidation product and, as a reduction equivalent, the novel lead(1+) complex [(Pb1+)2(μ-Ph2P···N···PPh2-)2](Pb-Pb) (3). The crystal structure determination of the red compound 3 shows a Pb-Pb bond length of 304.1(1) pm. The 31P- and 207Pb-NMR spectra of 3 are complicated due to the presence of a higher order spin system (AA′A′′A′′′X for the mono-207Pb isotopomer, AA′A′′A′′′XX′ for the bis-207Pb isotopomer). Simulations of the 31P and 207Pb spectra both on material with natural isotope abundance and on the 207Pb-labelled compound (3*) reveal a large Pb,Pb coupling constant of 7708 Hz, indicative of a covalent Pb-Pb bond. - Though InCl3 is diagonally related to PbCl2, no significant redox process is observed in the reaction between InCl3 and 1. The yellow crystals of [In3+(Ph2P···N···PPh2-)3] (4) that are obtained were also investigated by X-ray analysis. These show a propeller-like configuration of the three four-membered chelate rings with indium(3+) as the centre.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1434-193X
    Keywords: 1-Haloallenes ; Yne-allenes ; Allenes ; Sigmatropic rearrangements ; Cross-coupling ; Rearrangements ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Stille cross-coupling of the bromoallenes 3 with the stannylalkynes 6 or distannylalkyne 8 provided a convenient route for the synthesis of the conjugated yne-allenes 7 or the diastereomeric yne-diallenes, meso-9 and (R,R)/(S,S)-9. Analogously to 7, the phosphorylyne-allenes 14 were also prepared under Stille conditions, starting from the phosphorylallenes 12 and propargylstannane 6a. Alternatively, yne-allenes 17 and 18 were obtained from hexadiynol 16 with orthoester 2b or diethoxychlorophosphane 13a by [3.3]- and [2.3]-sigmatropic rearrangements.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 99-118 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloheptatrienes and Norcaradienes1): Relation between Hindrance of Rotation about the C-7-C-8 Bond and StructureIn order to elucidate factors responsible for substituent effects on cycloheptatriene-norcaradiene equilibria, the imidazolidinylium compound 12a and b, and the spiro molecules 13a and b are investigated. The synthesis of 12a starts from 7-cyanocycloheptatriene (14). Bisalkylation of dilithium heptafulvenediolate 17 affords 13. Compounds 12 and 13 are characterized by cycloadditions (→ 15, 22). Concerning the equilibrium 12a ⇌ 12b no norcaradiene could be traced by NMR. At room temperature 13a and b form a fast and dynamic equilibrium with [13a]:[13b] = 42:58. Thermodynamic parameters are given. The crystal structures of the compounds were determined by X-ray analysis. Both compounds are cycloheptatrienes with boat stereochemistry. The carbonyl group in 13a is exo, the cation substiuent in 12a is endo.
    Notes: Cycloheptatrien-7-ylimidazolidin-2-ylium-tetrafluoroborat (12a) wurde aus 7-Cyancycloheptatrien (14) und Aziridinium-tetrafluoroborat synthetisiert. Spirocycloheptatrien 13a und Norcaradien 13b entstehen durch cyclisierende Alkylierung des Dilithium-heptafulvendiolats 17. Mit Dienophilen bilden 12 und 13 die Polycyclen 15 und 22. NMR-Untersuchungen schließen einen nennenswerten Anteil von Norcaradien 12b im Gleichgewicht mit 12a aus. Dagegen stehen bei 284 K Cycloheptatrien 13a und Norcaradien 13b mit 42:58 im Gleichgewicht [ΔΔH0(NCD—CHT) = -1 kcal/mol, ΔΔS0(NCD—CHT) = -3 cal/Grad. mol]. Nach der Röntgenstrukturanalyse liegt 12a im Kristall in der Bootform mit endo-ständigem 7-Substituenten vor; von 13a ⇌ 13b ist im Kristall nur die Cycloheptatrienstruktur 13a mit exo-ständiger Carbonylgruppe stabil.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 0044-8249
    Keywords: Acyl-Anionen ; Carbenoide ; Lithiumverbindungen ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 107 (1995), S. 1446-1448 
    ISSN: 0044-8249
    Keywords: Arene ; Nucleophile aromatische Substitution ; Polykationen ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 0044-2313
    Keywords: Cobalt ; terahedrane complexes ; alkyne ; phosphalkyne ; bis(diphenylphosphanyl)amine ; X-ray structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Polyfunctional Molecules. 119 [1]. Tetracarbonyl-dicobalt-tetrahedrane Complexes with the Ligands Bis(diphenylphosphanyl)-amine, 2-Butin-1,4-diol, and tert.-Butylphosphaacetylene  -  Crystal Structure of the Phosphaalkyne DerivativeCo2(μ-CO)2(CO)4(μ-Ph2P—NH—PPh2 - P,P′) · 1/2C6H5CH3 (4 · 1/2C6H5CH3) reacts with 2-butine-1,4-diol, HOCH2—C≡C—CH2OH (5), to the dark-red tetrahedrane complex Co2(CO)4(μ-η2,η2-HOCH2—C≡C—CH2OH—C2, C3) · (μ-Ph2P—NH—PPh2—P,P′) · THF (6 · THF). With t-butyl-phosphaacetylene, tBu—C≡P (7), 4 · THF forms Co2(CO)4(μ-η2,η2-tBu—C≡P)(μ-Ph2P—NH—PPh2—P,P′) (8), which also belongs to the tetrahydrane type. The compounds were characterized by their mass, IR, 31P{1H} NMR, 13C{1H} NMR, and1H NMR spectra. Crystals suitable for X-ray structure analyses have been obtained for 8 from dioxane. The dark red blocks crystallize in the monoclinic P21/c space group with the lattice constants a = 1404,1(5), b = 1330,0(7), c = 2578,8(10)pm; β = 90,82(3)°.
    Notes: Co2(μ-CO)2(CO)4(μ-Ph2P—NH—PPh2—P,P′) · 1/2C6H5CH3 (4 · 1/2C6H5CH3) reagiert in THF mit 2-Butin-1,4-diol, HOCH2—C≡C—CH2OH (5), zu dem dunkelroten Tetrahedran-Komplex Co2(CO)4(μ-η2,η2-HOCH2—C≡C—CH2OH—C2, C3) · (μ-Ph2P—NH—PPh2—P,P′) · THF (6 · THF). Mit tert.-Butyl-phosphaacetylen, tBu-C≡P (7), bildet 4 den ebenfalls im Zentrum tetraedrisch strukturierten Komplex Co2(CO)4(μ-η2,η2-tBu—C≡P)(μ-Ph2P—NH—PPh2—P,P′) (8). Die Verbindungen werden an Hand ihrer Massen-, IR-, 31P{1H}-NMR-, 13C{1H}-NMR- und 1H-NMR-Spektren charakterisiert. Für eine Röntgenstrukturanalyse geeignete Kristalle wurden von 8 aus Dioxan erhalten. Die dunkelroten Kristalle von 8 · 2C4H8O2 kristallisieren in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 1404,1(5), b = 1330,0(7), c = 2578,8(10) pm; β = 90,82(3)° aus.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 0044-2313
    Keywords: Cyclometallaphosphazenes, Platin, Iron ; crystal structures ; IR, Raman, NMR, mass spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Polyfunctional Molecules. 118. Syntheses and Crystal Structures of Bicyclic Metallaphosphazenes with Four and Six Membered RingsAnhydrous MCl2 (M = Pt, Fe) react with LiN(PPh2)2 (1) in the molar ratio of 1:2 in boiling toluene within 25 hours under partially oxidative scrambling of the PNP chain in 1 yielding the bicyclic metallaphosphazenes 5 a, b. While compound 5 a can be isolated in substance, the intermediate 5 b proves to be highly reactive but can be stabilized in the presence of CO, forming the 18-valence-electron coordination compound as an isomeric trans(6 a)/cis(6 b) mixture in the molar ratio of 99:1. Also treatment of anhydrous PtCl4 with four equivalents of 1 in boiling toluene during 60 hours yields 5 a. Alkylation of 5 a with CH3I leads to the formation of the ionic species [Pt2+{Ph2P—N(CH3)—PPh2}(Ph2P—N = PPh2 = N—PPh2-)]I- (9). The X-ray crystal structures of 5 a × 1 CH2Cl2 and 6 a reveal, that the metal centres have a planar P-coordination polyhedron in the solid state. In the complex 9 × 2,5 CH2Cl2 however the torsion angle between the P—Pt—P planes of the four and six membered rings shows to be 15°. The six membered metallacycles in 5 a × 1 CH2Cl2, 6 a and 9 × 2,5 CH2Cl2 differ in their geometrical arrangement. All the new compounds have also been characterized by their 1H, 31P{1H}, 13C{1H} NMR, IR, Raman and mass spectra.
    Notes: Wasserfreies MCl2 (M = Pt, Fe) reagiert mit LiN(PPh2)2 (1) im Molverhältnis von 1:2 in siedendem Toluol während 25 Stunden unter teilweiser oxidativer Spaltung und Umgruppierung der PNP-Kette von 1 zu den bicyclischen Metallaphosphazenen 5 a, b. Während die Verbindung 5 a in Substanz isoliert werden kann, ist 5 b ein sehr reaktives Intermediat, das lediglich in Gegenwart von CO die 18-Elektronen-Verbindung bildet, die als trans(6 a)-/cis(6 b)-Isomerengemisch im Molverhältnis von etwa 99:1 anfällt. Die Umsetzung von wasserfreiem PtCl4 mit 1 im Molverhältnis 1:4 liefert nach 60-stündiger Reaktionszeit ebenfalls 5 a. Alkylierung von 5 a mit CH3l führt zum ionischen Komplex [Pt2+{Ph2P—N(CH3)—PPh2}(Ph2P—N = PPh2 = N—PPh2-)]I- (9). Kristallstrukturanalysen von 5 a × 1 CH2Cl2 und 6 a zeigen, daß die Metalle in ihnen quadratisch-planar durch die Phosphoratome koordiniert sind. Dagegen sind die (P—Pt—P)-Ebenen der Vier- und Sechsringe von 9 × 2,5 CH2Cl2 am metallischen Zentrum um 15° gegeneinander verdrillt. In 5 a × 1 CH2Cl2, 6 a und 9 × 2,5 CH2Cl2 besitzen die 6-gliedrigen Metallaphosphazenringe unterschiedliche Konformationen. Alle Verbindungen wurden außerdem durch 1H-, 31P{1H}-, 13C{1H}-NMR- sowie durch IR-, Raman- und Massenspektren charakterisiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    ISSN: 0044-2313
    Keywords: Ruthenium(II) Complexes ; Bis(diphenylphosphino)amine ; IR, Raman, NMR, UV/VIS spectra ; NMR Simulation ; Spin-Spin-Coupling-Constant-Assignments ; Crystal Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Polyfunctional Molecules. 116 Hydrido-, Deuterido-, Thiolato-, and Chlororuthenium(II) Complexes of Bis(diphenylphosphino)amineBis(diphenylphosphino)amine, [(C6H5)2P]2NH (dppa, 1), reacts with [Ru(cod)(cot)] (cod = η-1,5-cyclooctadiene, cot = η-1,3,5-cyclooctatriene) (2) in a molar ratio of 2 : 1 both in a hydrogen or deuterium atmosphere at room temperature to yield cis-[Ru(H)2(dppa)2] (3) and cis-[Ru(D)2(dppa)2] (3 a), respectively. The dihydride complex 3 is very sensitive towards halogenated solvents: dissolution of 3 in CHCl3 or CH2Cl2 produces the monohydride compound trans-[RuCl(H)(dppa)2] (4). Treatment of 3 with a threefold excess of tert-butyl mercaptane, Me3CSH, at room temperature results in the formation of cis-[Ru(H)(SCMe3)(dppa)2] (5). Trans-[RuCl2(dppa)2] (7) can be synthesized by the interaction of [RuCl2(PPh3)3] (6) with one or two equivalents of 1 in CH2Cl2 solution. The NMR spectra of 3, 3 a, 4, 5 and 7 are discussed with respect to molecular stereochemistry and hydrogen-halogen exchange under simultaneous cis-trans rearrangement. In addition to 1H, 2H, 31P{1H}, and 31P NMR, the structures of the different complexes were also derived from 1R, Raman, and mass spectra. The NMR spectra simulation of 3 permits detailed assignments of spin-spin coupling constants. Crystals of cis-[Ru(H)(SCMe3)(dppa)2] (5) are monoclinic, space group P21/c, with a = 1 179.9(3), b = 2 228.0(4), c = 1 854.8(6) pm, β = 96.23(2)°, Z = 4, and Rw = 0.062. The structural analysis shows that ruthenium is coordinated by two bidentate organophosphine ligands and by one tert-butyl thiolate molecule. The metal bound hydrogen atom was not located. However, in agreement with 1H NMR, its position is trans to a phosphorus nucleus.
    Notes: Bis(diphenylphosphino)amin, [(C6H5)2P]2NH (dppa, 1) reagiert mit [Ru(cod)(cot)] (cod = η-1,5-Cyclooctadien, cot = η-1,3,5-Cyclooctatrien) (2) im Molverhältnis 2 : 1 in Toluol bei Raumtemperatur sowohl in einer Wasserstoff- als auch einer Deuteriumatmosphäre zu cis-[Ru(H)2(dppa)2] (3) und cis-[Ru(D)2(dppa)2] (3 a). In CHCl3 oder CH2Cl2 entsteht aus 3 die Monohydrido-chloro-Verbindung trans-[RuCl(H) · (dppa)2] (4). Mit überschüssigem tert-Butylmercaptan, Me3CSH, liefert 3 in THF lediglich cis-[Ru(H)(SCMe3)(dppa)2] (5). Die Dichloroverbindung trans-[RuCl2(dppa)2] (7) ist durch Umsetzung von [RuCl2(PPh3)3] (6) mit einem oder zwei Äquivalenten 1 in CH2Cl2 zugänglich. Die NMR-Spektren von 3, 3 a, 4, 5 und 7 werden in bezug auf Molekülsymmetrien und Wasserstoff-Halogen-Austausch unter gleichzeitiger cis-trans-Umlagerung diskutiert. Neben 1H-, 2H-, 31P{1H}- und 31P-NMR-Spektren werden alle Verbindungen auch durch IR-, teilweise Raman- und Massen-Spektren charakterisiert. Die NMR-Spektren-Simulation von 3 ermöglicht genaue Zuordnungen von Spin-Spin-Kopplungskonstanten. Kristalle von cis-[Ru(H) · (SCMe3)(dppa)2] sind monoklin und kristallisieren in der Raumgruppe P21/c mit den Zellparametern a = 1179,9(3), b = 2 228,0(4), c = 1 854,8(6) pm, β = 96,23(2)°, Z = 4 und Rw = 0,062. Die Röntgenstrukturanalyse zeigt, daß Ruthenium von zwei chelatisierend wirkenden dppa-Liganden und dem Schwefel eines tert-Butylthiolatanions koordiniert ist. Das am Metall gebundene Wasserstoffatom konnte nicht exakt lokalisiert werden, jedoch ist es, in Übereinstimmung mit 1H-NMR-Daten, trans-ständig zu einem P-Atom.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 34 (1995), S. 1319-1321 
    ISSN: 0570-0833
    Keywords: arenes ; nucleophilic aromatic substitution ; polycations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 0570-0833
    Keywords: acyl anions ; carbenoids ; lithium compounds ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...