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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 12 (1992), S. 377-387 
    ISSN: 1573-1111
    Keywords: Charles Pedersen ; crown ethers ; phenol-pendant cyclam-zinc(II) complex ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The molecular structure of phenol-pendant cyclam-zinc(II) complex,4a, has been determined by X-ray structure analysis. Crystals of4a · ClO4 · CH3OH (C16H27N4OZn · ClO4 · CH3OH) are monoclinic, space groupP21/nn, with four molecules in the unit cell of dimensionsa=31.198(2) Å,b=8.426(1) Å,c=8.214(1) Å, andβ=93.96(1)°. The structure was solved by the heavy atom method and refined anisotropically toR=0.044,R w=0.062 for 1551 independent reflections. The complex assumes a five-coordinate, square pyramidal geometry, where zinc(II) is surrounded by the cyclam moiety in a planar fashion with the pendant phenolate anion occupying an axial position. An extremely short Zn-O(phenolate) bond distance of 1.983(5) Å, in conjunction with the 0.288 Å displacement of Zn(II) above the cyclam N4 plane toward the phenolate, accounts for the extremely low pK a value of 5.8 for the pendant phenol. These facts about4a, in comparison with the previous findings for the Ni(II) (4b) and Cu(II) complexes (4c) with the same ligand, illustrate well the characteristics of zinc(II) ion coordination properties.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-1111
    Keywords: Crystal structure ; properties ; new copper(II) complex ; dioxocyclam ; 8-methylquinoline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new macrocyclic dioxotetraamine ligand 1-(quinolin-8-ylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione (H2L) has been synthesized. The resulting dioxocyclam readily forms a 1 : 1 Cu(II) complex (CuL) with concomitant double deprotonation of the ligand. CuL has been isolated as single crystals and the structure was determined by X-ray diffraction analysis. CuL·5H2O (1·5H2O) crystallizes in monoclinic crystal system, P21/n space group with a = 12.979(2), b = 13.638(6), c = 13.634(4) Å, β = 103.02(2)°, V = 2351(2) Å3, Mr = 521.07, Z = 4, Dcalc = 1.472 g/cm3, μ = 9.78 cm-1, F(000) = 1100, room temperature, and R = 0.039, Rw = 0.042 for 2137 observed reflections with I 〉 3σ(I). In complex 1, the Cu atom is five coordinate to form a distorted square pyramid in which N(5) of the quinoline pendant is at the apical site. The Cu—N(5) bond distance (2.262(4) Å) is longer than the basal average Cu—N bond lengths (1.994(4) ring;). The behavior of CuL in solution has been studied further with ESR, UV-Vis and cyclic voltammetry.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 7 (1989), S. 183-191 
    ISSN: 1573-1111
    Keywords: Macrocyclic polyamines ; alkaline earth metals ; cyclam ; transition metal ion ; cyclic voltammetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract New, functionalized macrocyclic polyamines1, 9, 17, and20 have been synthesized for investigation of their metal and molecular inclusion.
    Type of Medium: Electronic Resource
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