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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 57 (1992), S. 4654-4658 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-1111
    Keywords: Calixarenes ; arenetricarbonylchromium ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structures of three arene-tricarbonylchromium complexes prepared from cone and 1,3-alternate-25, 26,27,28-tetrapropoxycalix[4]arene(1) and Cr(CO)6 were determined by single crystal X-ray studies. Crystal data for 1,3-alternate-1·Cr(CO)3 are space groupP21/a,a=19.496(3)Å,b=11.118(2)Å,c=19.121(2)Å, β=109.95°(1) andV=3895Å3. The structure was refined toRw=0.068. Crystal data for cone-1·Cr(CO)3 are space groupP21/a,a=21.457(4)Å,b=12.184(1)Å,c=14.816(2)Å, β=91.61°(1) andV=3872Å3. The structure was refined toRw=0.077. Crystal data for cone-1·2Cr(CO)3 are space groupP21/a,a=18.019(3)Å,b=41.347(4)Å,c=11.743(2)Å, β=97.39°(1) andV=8676Å3. The single crystal included two similar but slightly different structures but the data were successfully refined toRw=0.092. The structure of 1,3-alternate-1·Cr(CO)3 differs only slightly from that of the regular 1,3-alternate calix[4]arene. In contrast, cone-1·Cr(CO)3 and cone-1·2Cr(CO)3 show an unusual conformation with a pair of faced gablelike roofs, which is considerbly distorted from the regular cone calix[4]arene. The origin of this distortion is discussed in combination with the spectral studies.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 1537-1544 
    ISSN: 0947-3440
    Keywords: [3.1.1]Metacyclophanes ; Macrocycles ; Calixarenes ; Cyclobenzylation ; Solid superacid, Nafion-H ; Conformations ; Hydrogen bonding, intramolecular ; Metal cation complexation ; Ionophores ; Chirality ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hydroxy[3.1.1]metacyclophane 4c, which is regarded as an unsymmetric or uncomplete “homocalixarene” bearing a propane bridge, has been synthesized using Nafion-H catalyzed cyclobenzylation. A novel “pendulum” type motion steered by intramolecular hydrogen bonding has been observed Demethylation of compound 4c with BBr3 in methylene dichloride was carried out at room temperature for 3 h to afford the dihydroxy[3.1.1]metacyclophane 4b in 74% yield along with the triol 4a in 25% yield. Triol 4a was tri-O-alkylated with methyl iodide in the presence of NaH to yield partial-cone conformer 4d in quantitative yield. Similarly, a significant amount of partial-cone conformer 5 results in the case of O-alkylation of 4a with N,N-diethylchloroacetamide. 1H-NMR titration of partial-cone amide 5 with NaSCN clearly demonstrates that a 1:1 complex is formed which is stable on the NMR time scale.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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