ISSN:
1573-1111
Keywords:
Calix[8]arene
;
chairlike macrocycle shape
;
centrosymmetric
;
disorder
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Crystal structure analysis proves that thep-t-butylcalix[8]arene host sits around a symmetry center in thePI crystal lattice. The triclinic cell parameters and calculated volume are:a = 10.034(2),b = 17.434(2),c = 18.321(2) Å,α = 113.86(1)°,β = 93.08(1)°,γ = 92.62(1)°,V = 2919(2) Å3. ForZ = 1 and F.W. = 1834.6 the calculated density is 1.04 g/cm3. It is shown that the host macrocycle is in an open chairlike conformation and virtually leaves no cavity to be occupied by the guest molecule. Consequently the pyridine guest molecules are enclathrated through steric barriers into the crystal lattice, having only one of the guests in the asymmetric unit bound to the host. The open conformation of the host is facilitated by a break in the ring of O-O hydrogen bonds on the rim of the would-be calix. This structure also conveys essential information on the possible solution conformations of the host in pyridine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01041411
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