title: Bis[μ-1-hexyl-3-(2,3,5,6,8,9,11,12-octa-hydro-1,4,7,10,13-benzopenta-oxacyclo-penta-decin-15-yl)urea]bis-(azido-sodium) chloro-form disolvate.
abstract: In the title compound, [Na(2)(N(3))(2)(C(21)H(34)N(2)O(6))(2)]·2CHCl(3), the sodium cation is hepta-coordinated by five O atoms of the crown ether unit of the 1-hexyl-3-(2,3,5,6,8,9,11,12-octa-hydro-1,4,7,10,13-benzopenta-oxacyclo-penta-decin-15-yl)urea (L) ligand, the O atom of the urea group of the second, symmetry-related L ligand, and one N atom of the azide anion. The experimentally determined distance 2.472 (2) Å between the terminal azide N atom and the sodium cation is substanti-ally longer than that predicted from density functional theory (DFT) calculations (2.263 Å). The crown ethers complexing the sodium cation are related by an inversion centre and form dimers. The urea groups of the two L ligands are connected in a head-to-tail fashion by classical N-H⋯N hydrogen-bonding inter-actions and form a ribbon-like structure parallel to the b axis. Parallel ribbons are weakly linked through C-H⋯N, C-H⋯O and C-H⋯π inter-actions.
authors.affiliation: Institut Européen des Membranes, Université de Montpellier II, 34000 Montpellier,  France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gilles
authors.forename: Mihail
authors.initials: M
authors.lastname: Barboiu
authors.forename: Yves-Marie
authors.initials: YM
authors.lastname: Legrand
authors.forename: Arie
authors.initials: A
authors.lastname: van Lee