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  • Theoretical, Physical and Computational Chemistry  (1)
  • Werner complex  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 18 (1994), S. 317-329 
    ISSN: 1573-1111
    Keywords: Crystal structure ; clathrate ; Werner complex ; isothiocyanate ; 4-methylpyridine ; Mg(II)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two clathrate modifications of the title host with 4-methylpyridine (4-CH3C5H4N) as a guest have been determined at −50°C. [Mg(4-CH3C5H4N)4(NCS)2] · 2/3(4-CH3C5H4N) · 1/3H2O is trigonal, space group $$R\bar 3$$ , witha=27.630(7),c=11.219(3) ÅV=7417(4) Å3,Z=9,D calc=1.171 g cm−3,μ(CuK α)=18.506 cm−1, finalR=0.064. [Mg(4-CH3C5H4N)4(NCS)2] · (4-CH3C5H4N) is tetragonal, space group I4l/a, witha=16.944(7),c=23.552(9)Å,V=6762(5) Å,Z=8,D calc=1.191 g cm−3, μ(CuK α)=18.200 cm−1, finalR=0.071. The structures consist of molecular packings of the same host complex units and the guest species. The Mg(II) cation is octahedrally coordinated to theN-atoms of four 4-methylpyridine and twotrans-coordinated isothiocyanato ligands in the host molecule. The conformations of the molecule are considerably different both in symmetry and in geometry in these two structures. The guest 4-methylpyridine molecules are disordered into channels which have different topology in these two clathrates resulting in different thermal stability.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0894-3230
    Keywords: calix[4]resorcinarenes ; organophosphorus compounds ; solvatophobic interactions ; host-guest complexation ; high-performance liquid chromatography ; x-ray analysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Reversed-phase high-performance liquid chromatography [LiChrosorb RP-18,UV detection at 254 nm and acetonitrile-water (86:14,v/v) as mobile phase] was applied to studies of the host-guest complexation of tetraalkylcalix[4]resorcinareneoctols and their upper rim phosphoryl, sulfonyl and dialkylaminomethyl derivatives with some aromatic guests in the mobile phase. It was shown that the formation of the inclusion complexes results in changes in the retention of aromatic guests and improves their separation. Stability constants of the complexes were calculated from the dependences of the l/k′ values of the aromatic guest on the concentration of the calix[4]resorcinarene in the mobile phase. The molecular structure of 4,6,16,18-tetrahydroxy-10,12,22,24-tetrakis(dipropoxyphosphoryloxy)-2,8,14,20-tetramethylcalix[4]resorcinarene (12) was determined. Crystal data for 12 are P21/n, a  =  16.708(9) Å, b  =  18.683(6) Å, c  =  20.243(5) Å, β  =  95.75(3)°, V  =  6287(4) Å3 and Z  =  4. Compound 12 exists in a boat conformation, in which two opposite unsubstituted resorcinol rings of the macrocyclic skeleton lie in the plane formed by four methine bridges and two diphosphorylated rings are perpendicular to the plane. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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