Source of materialThec ompoundw as obtained commercially (Aldrich). Crystals suitable for the diffraction study were obtained upon recrystallizationfromethanol.
Experimental detailsCarbon-bound Hatoms were placed in calculated positions(C-H 0.95 Å) andwereincludedinthe refinement in the riding model approximation, with U iso (H) sett o1 .2U eq (C). The nitrogenbound Hatom was located on adifference Fourier map and refinedfreely.
DiscussionImidazole and its derivatives are versatile ligands in coordination chemistry due to their ability to act as mono-or bidentate ligands. Upon varying the substitution pattern on its aromatic core, its donor capabilities can be influenced over awide range which willin turn -allow finetuning and tailoring for the respective redox properties of the resultant coordination compounds. In addition, the change in absolute and relative Lewis basicity will allow for accomodating avastrange of (transition) metals as thecentral atomsinsuch coordination compounds. At the beginning of acomprehensive study aimed at elucidating structure-property relationships in imidazole-derived coordination compounds, the crystal and molecular structure of the title compound were determined to allow for direct comparisons of metrical parameters in thef reea nd thec oordinated ligand in envisioned target molecules. Structural information about coordination compounds derived from other imidazole derivatives are apparent in the literature, e.g. for1,2-dimethylimidazole and -among otherscadmium [1],copper [2] and ruthenium [3].The title compound is abrominated derivative of 1H-imidazole. Themolecule is essentially planar (r.m.s of all fitted non-hydrogen atoms=0.0129 Å) with the carbon atom bearing the bromine substituent deviating most from the commonplane by 0.018(2) Å. Intracyclic angles cover ar ange of 104.6(2)-111.4(3)°with the smallest angle found on the nitrogen atom that does not bear ahydrogen atom and the largest angle to be found on, both, the carbon atom bearing the bromine atom and the carbon atom bonded to both nitrogen atoms. The C-Br bond was measured at 1.870(3) Åwhich is in good agreement with the most commonv alues observed for other compounds featuring C-Br bonds whose metrical parameters have been deposited with the Cambridge Structural Database [4].Inthe crystal, intermolecular classical hydrogen bonds of the N-H×××Ntype in between the two different nitrogen atomsare apparent.These connectthe moleculestochainsalong thecrystallographic c axis in whichthe least-squaresplanesasdefined by the respective non-hydrogen atomsofthe individual molecules enclose angles of approximately 50.68°. In terms of graph-set analysis [5,6], the descriptor for these hydrogen bonds is C 1 1 (4) on the unary level. Theshortest intercentroid distance between two centersofgravity wasmeasuredat3.9396(19) Å.