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  • 1
    ISSN: 0022-328X
    Keywords: Dinuclear complexes ; Niobium ; Tantalum ; X-ray structures
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crown Thioether Complexes of Cobalt(III): Ligand Structure and Redoxreactivity. Crystal Structure, Electrochemistry, and Kinetics of the Electron Transfer Exchange Reactions of [Co(tacn)(ttcn)] Br3 · 3 H2O (tacn = 1,4,7-Triazacyclonone, ttcn = 1,4,7-Trithiacyclononane)Synthesis, crystal structure and redoxreactivity of [Co(tacn)(ttcn)]Br3 · 3 H2O (tacn = 1,4,7-triazacyclononane, ttcn = 1,4,7-trithiacyclononane) are reported. Average Co—S and Co—N bond distances are 2.247 Å and 1.961 Å, respectively. Cyclic voltammetry revealed two reversible electron transfer waves at +0.01 V vs. NHE ([Co(tacn)(ttcn)]3+/2+) and at -1.15 V vs. NHE ([Co(tacn)(ttcn)]2+/1+) at 25°C, I = 0.1 M. Electron transfer self exchange rate constants, k11, M-1 s-1, have been determined for the couples [Co(tacn)(ttcn)]3+/2+, [Co(ttcn)2]3+/2+, and [Fe(tacn)2]3+/2+ to be 4.2 X 104 (25°C; I = 0,1 M); 1.6 X 105 M-1 s-1 (25°C; I = 0.2 M); 4.6 x 103 M-1s-1 (25°C, I = 0.05) M-1 s-1, respectively. k11 for [Co(ttcn)2]3+/2+ has been determined using 1H NMR line-broadening techniques; for [Co(tacn)(tten)]3+/2+ and [Fe(tacn)2]3+/2+ the kinetics of the cross-reactions ([Ru(NH3)6]2+, respectively) have been measured, and K11 was evaluated using the Marcus-cross-relationship.
    Notes: Synthese, Kristallstruktur und Redoxreaktivität von [Co(tacn)(ttcn)]Br3 · 3 H2O (tacn = 1,4,7-Triazacyclononan; ttcn = 1,4,7-Trithiacyclononan) werden beschrieben. Mittlere Co—S- und Co—N-Bindungsabstände werden zu 2,247 Å bzw. 1,961 Å bestimmt. Das Redoxpotential für [Co(tacn)(ttcn)]3+/2+ bei 25°C (I = 0,1 M) ist + 0,01, während es für das Paar [Co(tacn) (ttcn)]2+/1+ bei -1,15 V gegen NHE mittels der cyclischen Voltammetrie bestimmt wurde. Die Elektronenaustauschgeschwindigkeitskonstante, k11, M-1 s-1, für [Co(tacn)(ttcn)]3+/2+ wurde über die Messung der Kinetik der gekreuzten Redoxreaktionen zwischen [Co(tacn)(ttcn)]3+ und [[Ru(NH3)6]2+ mit Hilfe der Marcus-Gleichung bestimmt: 4,2 X 104 M-1 s-1 (25°C, I = 0,1 M). Für das analoge Komplexpaar [Co(ttcn)2]3+/2+ wurde diese Konstante durch 1H-NMR-Linienverbreiterungsmethoden direkt gemessen: k11 = 1,6 X 105 M-1 s-1 (25°C; I = 0,2 M). Für [Fe(tacn)2]3+/2+ wurde diese Konstante pulsradiolytisch bestimmt: 4,6 X 103 M-1 s-1 (25°C, I = 0,05M).
    Additional Material: 9 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 551 (1987), S. 33-60 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrontransfer Barriers in CoN63+/CoN62+ Couples as a Function of the Ligand Structure. Correlations between the Structure and RedoxreactivityThe redox-reactivity of a series of CoN63+ complexes containing two saturated triamine ligands (open-chain and cyclic) has been systematically investigated. The perchlorate salts of 22 new amine complexes of the type [CoL2]3+ and [CoLL′]3+, where L and L′ represent different coordinated triamines, have been synthesized, their electronic spectra have been recorded and the redoxpotentials of CoN63+/2+ couples have been measured by use of cyclic voltammetry. The crystal structures of [Co(tacn)(dien)] I3, [Co(tacn)(etdien)] I3. H2O, and of [Co(budien)2]Br3. H2O (tacn = 1, 4, 7-triaza-cyclononane, dien = diethylenetriamine, etdien = N-(2-aminoethyl)-N-(ethyl)-1, 2-ethanediamine, budien = N-(2-aminoethyl)-N-(n-butyl)-1, 2-ethanediamine) have been determined by single crystal X-ray crystallography. The kinetics of the outer-sphere reductions of 14 CoN63+ complexes by [V(OH2)6]2+ have been measured and the electron transfer self-exchange rate constants of CoN63+/2+ couples have been calculated by use of the Marcus equation. Structure-redox-activity correlations are discussed in the frame of the semiclassical Marcus-Sutin model.
    Notes: Die Redoxreaktivität einer Serie von CoN63+-Komplexen mit jeweils zweigesättigten Triaminliganden (offenkettige und cyclische) wurde untersucht. Es wurden die Perchloratsalze von 22 neuen [CoL2]3+-bzw. [CoLL′]3+-Komplexen (L, L′= Triamin) dargestellt, ihre Elektronenspektren vermessen und die Redoxpotentiale für die CoN63+/2+-Paare mittels der cyclischen Voltammetrie bestimmt. Die Kristallstrukturen von [Co(tacn)(dien)]I3, [Co(tacn)(etdien)] I3. H2O und [Co(budien)2] Br3. H2O (tacn = 1,4,7-Triazacyclononan; dien = Diethylentriamin, etdien = N-(2-aminoethyl)-N-(ethyl)-1, 2-ethandiamin, budien = N-(2-aminoethyl)-N-(n-butyl)-1, 2-ethandiamin) wurden durch Einkristallröntgenstrukturanalysen bestimmt. Die Kinetik der outer-sphere Reduktion von 14 CoN63+-Komplexen mit [V(OH2)6]2+ wurde gemessen und die Elektronenaustauschgeschwindigkeitskonstanten für die Paare CoN63+/2+ mittels der Marcus-Gleichung bestimmt. Struktur-Redoxreaktivitätbeziehungen werden im Rahmen des semiklassischen Marcus-Sutin-Modells diskutiert.
    Additional Material: 7 Ill.
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination Chemistry of Gallium(III) with Macrocyclic Ligands. Synthesis and Crystal Structure of Di-μ-hydroxo-μ-acetato-bis[(1,4,7-triazacyclononane)gallium(III)] Triiodide · MonohydrateThe coordination chemistry of 1,4,7-triazacyclononane (L) and N,N′,N″-trimethyl-1,4,7-triazacyclononane (L′) with gallium(III) has been investigated. Monomeric species LGaCl3 and L′GaCl3 have been isolated from nonaqueous solutions of GaCl3 and the respective amine. From alkaline, aqueous solutions of Ga(NO3)3, and the respective amine binuclear complexes have been isolated; [L2Ga2(OH)2(μ-OH)2](ClO4)2 · 5 H2O, [L2Ga2(μ-CH3CO2)(μ-OH)2]I3 · H2O. [L′2Ga2(μ-OH2CH3CO2)2](ClO4)4 · H2O was obtained from a methanolic solution of Ga(NO3)3 and NaCH3CO2. [L2Ga2(μ-OH)2(μ-CH3CO2)]I3 · H2O crystallizes in the monoclinic space group P21/a (Z = 4); two GaIII-centers are connected via two OH- and one acetato-bridge.
    Notes: Die Koordinationschemie der Liganden 1,4,7-Triazacyclononan (L) und N,N′,N″-Trimethyl-1,4,7-triazacyclononan (L′) mit Gallium(III) wurde untersucht. Die monomeren Komplexe LGaCl3 und L′GaCl3 wurden aus nichtwäßrigen Lösungsmitteln erhalten. Aus alkalischer, wäßriger Lösung von Ga(NO3)3 und dem jeweiligen Amin konnten [L2Ga2(OH)2(μ-OH)2](ClO4)2 · 5 H2O, [L2Ga2(μ-CH3CO2)(μ-OH)2]I3 · H2O, zweikernige Komplexe, isoliert werden. Aus methanolischer Lösung wurde [L′2Ga2(μ-OH2)(μ-CH3CO2)2](ClO4)4 · H2O kristallin erhalten. [L2Ga2(μ-OH)2(μ-CH3CO2)]I3 · H2O kristallisiert monoklin P21/a mit Z = 4; zwei GaIII-Zentren sind über zwei OH- und eine Acetat-Brücke miteinander verknüpft.
    Additional Material: 1 Ill.
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  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and molecular structure of 1,1,3,3-tetraphenyl-2,4-bis(triphenylphosphonio)-15,3lambda;5-diphosphacyclobutadiene Dinitrate Hydrate[(C6H5)3PCP(C6H5)2]2(NO3)2 · H2O is monoclinic (P21/n) with a = 12.173 (15), b = 15.583 (3), c = 14.353 (17) Å, β = 102.86 (3)7deg;, Z = 2. The structure was solved by direct methods and refined by least squares to R = 0.062. The compound contains the centrosymmetric cation The bond distances in the four-membered ring and to the exocyclic P atoms show that the delocalization of the double bonds (or the positive charges) extends over the exocyclic P atoms, too.
    Notes: [(C6H5)3PCP(C6H5)2]2(NO3)2 · H2O kristallisiert monoklin, in der Raumgruppe P21/n mit a = 12,173 (15). b = 15,583 (3), c = 14,353 (17) Å, = 102,86 (3), Z = 2. Die Struktur wurde mit direkten Methoden bestimmt und nach der Methode der kleinsten Quadrate bis zu einem R-Wert von 0,062 verfeinert. Das zugrunde liegende Kation ist zentrosymmetrisch. Die Bindungsabstände im zentralen viergliedrigen Ring und zu den exocyclischen P-Atomen zeigen, daß in die Delokalisierung der Doppelbindungen bzw. der positiven Ladungen auch die exocyclischen P-Atome mit eingeschlossen sind.
    Additional Material: 4 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 474 (1981), S. 96-104 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trigonal Crystallizing Metal(II) Hexacyanoferrates(II) M2II[Fe(CN)6]According to X-ray powder diagrams, Ca2[Fe(CN)6], Cd2[Fe(CN)6], Zn2[Fe(CN)6] · 2 H2O, Pb2[Fe(CN)6] and the firstly described compounds Zn2[Fe(CN)6] · 2 NH3 and Sn2[Fe(CN)6] crystallize trigonal containing one formula unit in the unit cell. Ca2[Fe(CN)6] and Cd2[Fe(CN)6] are belonging to the space group D3d1 - P31m, the other compounds to D3d3 - P3m1. The latters are described as coordination polymers with a coordination number 4 for Zn and 3 for Sn and Pb, respectively.
    Notes: Nach Röntgenpulverdiagrammen kristallisieren Ca2[Fe(CN)6], Cd2[Fe(CN)6], Zn2[Fe(CN)6] · 2H2O und Pb2[Fe(CN)6] sowie die erstmalig beschriebenen Verbindungen Zn2[Fe(CN)6] · 2 NH3 und Sn2[Fe(CN)6] trigonal mit einer Formeleinheit in der Elementarzelle. Für Ca2[Fe(CN)6] und Cd2[Fe(CN)6] wird die Raumgruppe D3d3 - P31m festgestellt. Die übrigen Substanzen kristallisieren in der Raumgruppe D3d3 - P31m, hier handelt es sich um Koordinationspolymere mit der Koordinationszahl 4 (Zn) bzw. 3 (Sn, Pb) am Kation.
    Additional Material: 2 Ill.
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  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crown Thioether Complexes of Lead (II), Zinc(II), and Cadmium (II). Crystal Structures of [PbL2(ClO4)2] and [ZnL2](ClO4)2 · CH3CN (L = 1,4,7 - Trithiacyclononane)The reaction of 1,4,7-trithiacyclononane (L) with the perchlorate salts of lead(II) and zinc(II) in CH3CN (2:1) affords colorless crystals of [PbL2(ClO4)2] and [ZnL2](ClO4)2 · CH3CN, respectively, The crystal structures have been determined. The PbII centre is coordinated to six sulfur atoms (the average distance Pb—S is 3.076 Å) and two oxygen atoms, one of each ClO4- anion (monodentate ClO4-). A distorted square antiprismatic polyhedron is thus generated. In [ZnL2](ClO4)2 · CH3CN the zinc(II) centre is octahedrally surrounded by six sulphur atoms (average distance Zn—S = 2.494 Å); the ClO4- anions are not coordinated. For[CdL2](ClO4)2 · H2O an analogous structure is proposed.
    Notes: Die Umsetzung von 1,4,7-Trithiacyclononan (L) mit den Perchloratsalzen des Blei(II) und Zink(II) in CH3CN (2:1) führt zu den farblosen Salzen [PbL2(ClO4)2] und [ZnL2](ClO4)2 · CH3CN. Die Kristallstrukturen wurden bestimmt: Das PbII-Ion ist von 6 Thioether-schwefelatomen (mittlerer Abstand Pb—S 3,076 Å) sowie zwei O-Atomen von jeweils einem ClO4-Anion (einzähnig koordiniertes ClO4-) umgeben, wodurch ein verzerrt quadratisch antiprismatisches Koordinationspolyeder am PbII erzeugt wird.Im [ZnL2](ClO4)2 · CH3CN ist das ZnII oktaedrisch von sechs Schwefelatomen umgeben (mittlerer Abstand Zn—S = 2,494 Å); die ClO4--Anionen sind nicht koordiniert. Für [CdL2](ClO4)2 · H2O, das ebenfalls dargestellt wurde, wird eine analoge Struktur vorgeschlagen.
    Additional Material: 3 Ill.
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  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination-chemistry of cis-Trioxotungsten(VI) Complexes. Crystal Structures of LWO3 · 3 H2O, [L′WO2(OH)]Br, [LWO2Br]Br, [L2W2O5](S2O6) · 4 H2O and [LWO2(μ-O)WO(O2)2(OH2)] (L = 1,4,7-Triazacyclonane; L′ = 1,4,7-Trimethyl-1,4,7-triazacyclononane)The cyclic triamines 1,4,7-triazacyclononane (L; C6H15N3) and 1,4,7-trimethyl-1,4,7-triazacyclononane (L′; C9H21N3) react in aqueous solution with WO3 affording LWO3 · 3 H2O, 1, and L′WO3 · 3 H2O, respectively, which yield [L′WO2(OH)]Br, 2, and [LWO2Br]Br, 3, in concentrated HBr solutions. In aqueous CH3SO3H solution 1 dimerizes. The iodide and dithionate 4 salts of [L2W2O5]2+ have been isolated. In 35% H2O2 complex 1 yields the neutral species [LWO2(μ-O)WO(O2)2(H2O)] 5. The crystal structures of 1-5 have been determined by X-ray analysis. Crystal data: 1: P21/c; a = 7.729(2), b = 14.887(3), c = 10.774(2) Å, β = 90.77(2)°, Z = 4; 2: Cc; 8.910(3), b = 12.220(6), c = 13.279(6) Å, β = 101.31(3)°, Z = 4; 3: Cmc21, a = 8.857(5), b = 12.062(7), c = 11.218(7) Å, Z = 4; 4: Cc, a = 17.601(7), b = 12.906(7), c = 14.107(8) Å, β = 124.08(4)°, Z = 4; 5: P212121; a = 8.452(4), b = 11.301(6), c = 13.750(6) Å, Z = 4.
    Notes: Die cyclischen Triamine 1,4,7-Triazacyclononan (L; C6H15N3) und 1,4,7-Trimethyl-1,4,7-triazacyclononan (L′; C9H21N3) reagieren in wäßriger Lösung mit WO3 zu LWO3 · 3 H2O, 1, bzw. L′WO3 · 3 H2O, deren Umsetzung mit HBr zu [L′WO2(OH)]Br, 2, bzw. [LWO2(Br)]Br, 3, führt. In wäßriger CH3SO3H-Lösung dimerisiert 1 zu [L2W2O5]2+, das als Iodidoder Dithionatsalz, 4, kristallin erhalten wurde. Mit 35% H2O2 reagiert 1 unter Bildung des zweikernigen Neutralkomplexes [LWO2(μ-O)WO(O2)2(H2O)], 5. Die Kristallstrukturen von 1-5 wurden bestimmt. Kristalldaten 1: P21/c; a = 7,729(2), b = 14,887(3), c = 10,774(2) Å, β = 90,77(2)°, Z = 4; 2: Cc; 8,910(3), b = 12,220(6), c = 13,279(6) Å, β = 101,31(3)°, Z = 4; 3: Cmc21, a = 8,857(5), b = 12,062(7), c = 11,218(7) Å, Z = 4; 4: Cc, a = 17,601(7), b = 12,906(7), c = 14,107(8) Å, β = 124,08(4)°, Z = 4; 5: P212121; a = 8,452(4), b = 11,301(6), c = 13,750(6) Å, Z = 4.
    Additional Material: 5 Ill.
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