title: Acetyl-ene-ammonia-18-crown-6 (1/2/1).
abstract: The title compound, C(2)H(2)·C(12)H(24)O(6)·2NH(3), was formed by co-crystallization of 18-crown-6 and acetyl-ene in liquid ammonia. The 18-crown-6 mol-ecule has threefold rotoinversion symmetry. The acteylene mol-ecule lies on the threefold axis and the whole mol-ecule is generated by an inversion center. The two ammonia mol-ecules are also located on the threefold axis and are related by inversion symmetry. In the crystal, the ammonia mol-ecules are located below and above the crown ether plane and are connected by inter-molecular N-H⋯O hydrogen bonds. The acetyl-ene mol-ecules are additionally linked by weak C-H⋯N inter-actions into chains that propagate in the direction of the crystallographic c axis. The 18-crown-6 mol-ecule [occupancy ratio 0.830 (4):0.170 (4)] is disordered and was refined using a split model.
authors.affiliation: Institut für Anorganische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg,  Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Grassl
authors.forename: Markus
authors.initials: M
authors.lastname: Hamberger
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Korber