title: Ionothermal synthesis and crystal structure of a new organic-inorganic hybrid compound: catena-poly[bis(1-ethyl-3-methylimidazolium) [hepta-μ-bromido-pentacuprate(I)]].
abstract: A new organic-inorganic hybrid compound, catena-poly[bis(1-ethyl-3-methylimidazolium) [μ5-bromido-tri-μ3-bromido-tri-μ2-bromido-pentacuprate(I)]], {(C6H11N2)2[Cu5Br7]}n, has been obtained under ionothermal conditions from a reaction mixture containing Ba(OH)2·8H2O, Cu(OH)2·2H2O, As2O5, 1-ethyl-3-methylimidazolium bromide and distilled water. The crystal structure consists of complex [Cu5Br7](2-) anions arranged in sinusoidal {[Cu5Br7](2-)}n chains running along the a axis, which are surrounded by 1-ethyl-3-methylimidazolium cations. Three of the five unique Br atoms and one of the three Cu(I) atoms occupy special positions with half-occupancy (a mirror plane perpendicular to the b axis, site symmetry m). The Cu(I) ions are in a distorted tetrahedral coordination environment, with four Br atoms at distances ranging from 2.3667 (10) to 2.6197 (13) Å, and an outlier at 3.0283 (12) Å, exceptionally elongated and with a small contribution to the bond-valence sum of only 6.7%. Short C-H···Br contacts build up a three-dimensional network. The Cu···Cu distances within the chain range from 2.8390 (12) to 3.0805 (17) Å, indicating the existence of weak Cu(I)···Cu(I) cuprophilic interactions.
authors.affiliation: University of Belgrade, Faculty of Mining and Geology, Laboratory of Crystallography, Đušina 7, 11000 Belgrade, Serbia.
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Karanović
authors.affiliation: University of Belgrade, Department of General and Inorganic Chemistry, Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia.
authors.forename: Dejan
authors.initials: D
authors.lastname: Poleti
authors.affiliation: Universität Wien, Institut für Mineralogie und Kristallographie, Althansstrasse 14, A-1090 Vienna, Austria.
authors.forename: Tamara
authors.initials: T
authors.lastname: Đorđević
keywords: 1-ethyl-3-methylimidazolium bromide; Cu...Cu interactions; copper(I) bromide; crystal structure; ionothermal synthesis; organic–inorganic hybrid compound