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  • Electronic Resource  (4)
  • 1990-1994  (4)
  • 1975-1979
  • 1993  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Matrix-assisted laser desorption/ionization mass spectrometry with additives to 2,5-dihydroxybenzoic acid (1993)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 28 (1993), S. 1476-1481 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Selected benzoic acid derivatives and related substances were used as additives to 2,5-dihydroxybenzoic acid (2,5DHB) and the performance of the mixtures in matrix-assisted laser desorption/ionization mass spectrometry was investigated. Using benzoic acid derivatives substituted at position 2 and/or 5 or related substances as a co-matrix in the 1-10% range with 2,5DHB results in improved ion yields and signal-to-noise ratio of analyte molecules, especially for the high-mass range. The enhanced performance is prominent for 2-hydroxy-5-methoxybenzoic acid and exists for both proteins and oligosaccharides. It is suggested that the improvement is caused by a disorder in the 2,5DHB crystal lattice allowing ‘softer’ desorption. Charge transfer from matrix ions to additive molecules at the expense of analyte ionization gives a simple explanation for the deteriorating effects of some tested additives.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210281219
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  • 2
    Electronic Resource
    Electronic Resource
    Reaktive E = C(p-p)π-Systeme, XXXIII. Side-on-Koordination des Phosphaalkins P ≡ C  -  N(iPr)2 im 16e-Nickel(0)-Komplex Ni(CO)PCy3[PCN(iPr)2] (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 63-65 
    Details
    ISSN: 0009-2940
    Keywords: Phosphaalkyne, amino- ; Nickel carbonyl phosphane complex ; π Coordination ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactive E = C(p-p)π Systems, XXXIII.  -  Side-on Coordination of the Phosphaalkyne P ≡ C  -  N(iPr)2 in the 16e Nickel(0) Complex Ni(CO)PCy3[PCN(iPr)2]The reaction of (diisopropylamino)phosphaethyne P ≡ C  -  N(iPr)2 with the nickel complex [Ni(CO)3PCy3] - in contrast to the analogous reactions with Ni(CO)4 or Ni(CO)3PR3 (R = Me, Ph) - leads to the novel 16e nickel(0) system [Ni{η2-P ≡ C  -  N(iPr2)}(CO)PCy3] with a planar geometry of all skeleton atoms besides the methyl and cyclohexyl groups. Side-on coordination of the P ≡ C triple bond results in an increase of the PC distance to 1.665 Ȧ typical for phosphaalkenes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260111
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  • 3
    Electronic Resource
    Electronic Resource
    Zink-Koordinationsverbindungen mit Imidazolin- und Imidazol-DonorligandenProfessor Dietrich Mootz zum 60. Geburtstage gewidmet (1993)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1183-1195 
    Details
    ISSN: 0044-2313
    Keywords: Zinc complexes ; imidazole ; imidazoline ; bisimidazoline complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zinc Coordination Compounds with Imidazoline and Imidazole Donor Ligands.By reaction of the two bidentate bisimidazoline ligands 1,2-bis(2-imidazoline-2-yl)ethan (BIE) and 1,2-bis(2-imidazoline-2-yl)benzene (BIB) with zinc bromide under various reaction conditions the complexes [ZnBr2(BIE)] (1), [ZnBr2(BIB)] (2), [Zn(BIE)2]Br2 (3) and [Zn(BIB)2](BPh4)2 (4) were synthesized and characterized. In all compounds the zinc atom is tetrahedrally coordinated, either by a bidentate ligand and two bromine ligands, or by two of the chelate ligands. Zn—N—bond distances for 1-4 range from 1.966(2) to 2.013(3) Å, and the Zn—Br distances from 2.372(1) to 2.403(1) Å. [3-(imidazole-1-yl)-1-oxopropyl]benzene (IOB) was prepared as a novel imidazole ligand which carries a keto-O atom in 1,5-position to the pyridine-N atom. The zinc in [ZnCl2(IOB)2] (5) is coordinated by two ligands and two Cl atoms forming a distorted tetrahedral ZnN2Cl2 unit (Zn—N: 2.013(3) and 2.029(2) Å; Zn—Cl: 2.226(1) and 2.242(1) Å).The colourless compounds 1-5 were characterized by IR, 1H-NMR, X-ray absorption spectra and single-crystal X-ray structure analysis. Space groups and structural data: 1: P21/c, a = 7.717(2), b = 22.814(5), c = 8.026(2) Å, β = 117.58(2)° (140 K), R = 0.0283; 2: Cc, a = 11.831(3), b = 11.677(1), c = 11.846(1) Å, β = 114.55(2)°, R = 0.0237; 3: P42/n, a = 7.931(1), c = 16.945(1) Å, R = 0.0312; 4: P21/c, a = 18.666(2), b = 16.615(2), c = 19.786(2) Å, β = 99.17(1)°, R = 0.0472; 5: P21/c, a = 9.173(2), b = 9.230(1), c = 28.357(3) Å, β = 96.63(1)°, R = 0.0317.
    Notes: Durch Umsetzungen der zweizähnigen Bisimidazolin-Liganden 1,2-Bis(2-imidazolin-2-yl)ethan (BIE) und 1,2-Bis(2-imidazolin-2-yl)benzol (BIB) mit Zinkbromid unter verschiedenen Reaktionsbedingungen konnten die Komplexverbindungen [ZnBr2(BIE)] (1), [ZnBr2(BIB)] (2), [Zn(BIE)2]Br2 (3) und [Zn(BIB)2](BPh4)2 (4) synthetisiert und charakterisiert werden. Das Zinkatom ist jeweils tetraedrisch von einem zweizähnigen Chelatliganden und zwei Bromatomen oder von zwei dieser Liganden koordiniert. Die Zn—N-Bindungslängen in 1-4 variieren zwischen 1,966(2) und 2,013(3) Å, für die Zn—Br-Abstände wurden Werte zwischen 2,372(1) und 2,403(1) Å beobachtet. Mit dem neuen Liganden [3-(Imidazol-1-yl)-1-oxopropyl]benzol (IOB) gelang die Synthese des Komplexes [ZnCl2(IOB)2] (5), in dem eine tetraedrische ZnN2Cl2-Koordinationseinheit vorliegt (Zn—N: 2,013(3) und 2,029(2) Å; Zn—Cl: 2,226(1) und 2,242(1) Å).Die farblosen Verbindungen 1-5 wurden durch IR-, 1H-NMR- und Röntgenabsorptionsspektren sowie durch vollständige Röntgenstrukturanalysen charakterisiert. Raumgruppen und Gitterkonstanten: 1: P21/c, a = 7,717(2), b = 22,814(5), c = 8,026(2) Å, β = 117,58(2)° (140 K), R = 0,0283; 2: Cc, a = 11,831(3), b = 11,677(1), c = 11,846(1) Å, β = 114,55(2)°, R = 0,0237; 3: P42/n, a = 7,931(1), c = 16,945(1) Å, R = 0,0312; 4: P21/c, a = 18,666(2), b = 16,615(2), c = 19,786(2) Å, β = 99,17(1)°, R = 0,0472; 5: P21/c, a = 9,173(2), b = 9,230(1), c = 28,357(3) Å, β = 96,63(1)°, R = 0,0317.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19936190707
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  • 4
    Electronic Resource
    Electronic Resource
    Synthese und Kristallstruktur einer Neuen hexagonalen Modifikation von Al2S3 mit fünffach koordiniertem AluminiumProfessor Heinrich Nöth zum 65. Geburtstage gewidmet (1993)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 983-988 
    Details
    ISSN: 0044-2313
    Keywords: Aluminum sulfide ; crystal structure ; chemical transport ; five-coordinated aluminum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of a Novel Hexagonal Modification of Al2S3 with Five-coordinated AluminumA new hexagonal high temperature modification of Al2S3 could be prepared by chemical vapour transport with iodine (860 → 750°C) or by annealing of α -Al2S3 at 550°C. According to the single crystal X-ray structure determination the novel form of Al2S3 crystallizes in space group P 61 (No. 169) with a = 6.491(1), c = 17.169(4) Å, V = 626.5 Å3, Z = 6; R = 0.0253. In this modification one half of the aluminum atoms are tetrahedrally coordinated [d(Al—S): 2.226-2.267 Å], whereas the other half are in trigonal bipyramidal coordination of five S atoms with bond lengths of 2.272-2.315 Å (equatorial) and 2.495-2.521 Å (axial).Aluminum in AlS5 coordination is observed for the first time in this compound. The crystal structure is isotypic to In2Se3 and AlInS3. In addition, results of a refinement of the α -Al2S3 crystal structure are reported which were obtained on crystals prepared also by chemical vapour transport with iodine.
    Notes: Eine bisher noch nicht beschriebene hexagonale Hochtemperatur-Modifikation von Al2S3 konnte in reiner Form entweder durch chemischen Transport mit Iod (860 → 750°C) oder durch Tempern von α -Al2S3 oberhalb 550°C erhalten und durch eine Einkristall-Röntgenstrukturanalyse charakterisiert werden.Die neue Form des Al2S3 kristallisiert in der Raumgruppe P 61 (Nr. 169) mit a = 6,491(1), c = 17,169(4) Å, V = 626,5 Å3, Z = 6; R = 0,0253. In dieser Modifikation liegt die eine Hälfte der Aluminiumatome tetraedrisch koordiniert vor [d(Al—S): 2,226-2,267 Å], während die andere Hälfte trigonal-bipyramidal von fünf S-Atomen mit Al—S-Bindungslängen von 2,272 bis 2,315 Å (äquatorial) und 2,495-2,521 Å (axial) umgeben ist.Aluminium in AlS5-Koordination ist bisher unbekannt und wird hier zum ersten Mal beobachtet. Die Struktur ist isotyp zu In2Se3 und AlInS3. Zusätzlich wird über die Verfeinerung der Kristallstruktur α von -Al2S3 an Einkristallen berichtet, die ebenfalls durch chemischen Transport mit Iod hergestellt wurden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19936190604
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