title: Crystal structure of the tetra-gonal polymorph of bis-(1-ethyl-3-methyl-imidazolium) tetra-bromido-cadmate.
abstract: Both unique Cd atoms in the tetra-gonal polymorph of bis-(1-ethyl-3-methyl-imidazolium) tetra-bromido-cadmate, (C6H11N2)2[CdBr4], occupy special positions (site symmetry -4). The crystal structure consists of isolated tetra-hedral [CdBr4](2-) anions which are surrounded by 1-ethyl-3-methyl-imidazolium cations. The methyl and ethyl side chains of the cations show positional disorder in a 0.590 (11):0.410 (11) ratio. In the crystal, (C6H11N2)(+) cations display three weak C-H⋯Br hydrogen-bond inter-actions through the imidazolium ring H atoms with the Br(-) ligands of the surrounding complex anions. The alkyl groups of the side chains are not involved in hydrogen bonding.
authors.affiliation: Institut für Mineralogie und Kristallographie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Tamara
authors.initials: T
authors.lastname: Đorđević
authors.affiliation: Institut für Mineralogie und Kristallographie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Gerger
authors.affiliation: Laboratory of Crystallography, Faculty of Mining and Geology, Đušina 7, 11000 Belgrade, Serbia.
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Karanović
keywords: 1-ethyl-3-methyl imidazolium bromide; crystal structure; ionothermal synthesis; supra­molecular organization; tetra­bromido­cadmate