0000000000699676
AUTHOR
Vasiliy V. Brusko
Functionalized Calix[8]arenes, Synthesis and Self-assembly on Graphite
With the intention of building hollow tubular structures by self-assembly, we have designed and successfully synthesized a series of calix[8]arene derivatives. Their phenolic units were functionalized in p-position by various groups which are able to interact via hydrogen bonding or π−π stacking. Ethynyl, amide, urea, or imide links were chosen for the covalent attachment of these functional groups, to ensure the adjustment of an optimal distance for their interaction. Two different kinds of nanostructures self-assembled on a highly oriented pyrolytic graphite (HOPG) surface were found by scanning force microscopy: parallel aligned nanorods in which the calixarene molecules are adsorbed ed…
Crystal structure of t-Butylcalix[8]arene octamethyl ether
Abstract The title compound 1a crystallized with a molecule of chloroform in a triclinic lattice, space group P-1, with a=16.5215(19) A, b=17.4181(19) A, c=18.7403(18) A, α=78.328(8)°, β=64.210(8)°, γ=87.863(9)°, Z=2. The molecule assumes a not yet observed conformation with approximate (not crystallographic) C4V-symmetry with the inclusion of one molecule of chloroform in the molecular cavity. Layers of molecules are packed in alternating order in the crystal lattice.
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrapentoxycalix[4]arene
The molecule of the title compound, C64H96O4, adopts the typical pinched-cone conformation. The dihedral angles between the reference plane (defined by the C atoms of the methylene bridges) and the benzene rings are 86.88 (4), 136.64 (5), 87.22 (4) and 133.99 (4)°.
Supramolecular structures formed by calix[8]arene derivatives.
Octamethoxy calix[8]arenes substituted in the para position by amide, urea, and imide functions were synthesized from the octamethyl ether of tert-butylcalix[8]arene by ipso nitration, reduction, and acylation. Scanning force microscopy of spin coated samples on graphite suggests that these derivatives self-organize into tubular nanorods via hydrogen bonds between p-amide functions. A single-crystal X-ray structure reveals a centrosymmetric conformation for the octanitro derivative. [structure: see text]