0000000000684606

AUTHOR

Jörg Brenn

showing 2 related works from this author

Conformational properties of methylene bridged resorcarenes

1998

Abstract Conformations and conformational interconversions of resorcarene 1c have been studied by molecular mechanics calculations. As with calix[4]arenes the general stability of the four basic conformations is cone > partial cone > 1,2-alternate > 1,3-alternate. The lowest energy is calculated for a pinched cone conformer with C2v symmetry stabilised by intramolecular hydrogen bonds of the two “parallel” resorcinol units as donors. The topomerisation of the cone conformation proceeds via the partial cone and 1,2-alternate intermediates with a calculated barrier of 9.9 kcal mol−1 which is in excellent agreement with the experimental value.

Hydrogen bondChemistryOrganic ChemistryResorcinolResorcinareneBiochemistryCrystallographychemistry.chemical_compoundCone (topology)Computational chemistryIntramolecular forceDrug DiscoveryCalixareneMethyleneConformational isomerismTetrahedron
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Ring inversion pathways of exo- and endo-calix[4]arenes studied by means of the MM3 force field

1995

Abstract The ring inversion pathways of an exo-calix[4]arene 1a and of p-tert-butylcalix[4]arene 2a were investigated by means of the dihedral driver option of the MM3(92) force field. The calculated activation energies of 14.0 and 6.7 kcal mol−1 are in excellent agreement with the experimentally determined value for p-tert-butylcalix[4]arene and the observed flexibility of the exo-calix[4]arene on the NMR timescale.

CrystallographyRing flipChemistryOrganic ChemistryDrug DiscoveryDihedral angleBiochemistryForce field (chemistry)Tetrahedron Letters
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