title: 5,11,17,23-Tetra-kis(chloro-meth-yl)-25,26,27,28-tetra-propoxycalix[4]arene.
abstract: The title calix[4]arene, C(44)H(52)Cl(4)O(4), displays the 1,3-alternate conformation with crystallographically imposed twofold symmetry. Four phenolic rings of the calixarene backbone are tilted into the calix cavity, making dihedral angles of 77.42 (2) and 77.71 (2)° with the plane of the four bridging methyl-ene C atoms. Pairs of opposite aromatic rings make dihedral angles of 25.16 (3) and 24.58 (4)° with each other. In the crystal, the calixarene mol-ecules pack with the formation of infinite columns along the b axis. The crystal packing shows a network of C-H⋯Cl contacts, which can be considered as non-classical hydrogen bonds.
authors.forename: Felix
authors.initials: F
authors.lastname: Kutter
authors.forename: Matthias H
authors.initials: MH
authors.lastname: Düker
authors.forename: Matthias
authors.initials: M
authors.lastname: Zeller
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Azov