Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Mixtures of AlX<jats:sub>3</jats:sub> (X=Cl, Br) with 1‐butylimidazole (BuIm) in various ratios were investigated. The mixtures were characterized by multinuclear (<jats:sup>1</jats:sup>H, <jats:sup>27</jats:sup>Al, <jats:sup>13</jats:sup>C, and <jats:sup>15</jats:sup>N) NMR, IR, and Raman spectroscopy and in part by single‐crystal X‐ray diffraction. Depending on the molar fraction <jats:italic>x</jats:italic>(AlBr<jats:sub>3</jats:sub>) of the AlBr<jats:sub>3</jats:sub>‐based mixtures, the cationic aluminum complexes [Al(BuIm)<jats:sub>6</jats:sub>]<jats:sup>3+</jats:sup> and [AlBr<jats:sub>2</jats:sub>(BuIm)<jats:sub>4</jats:sub>]<jats:sup>+</jats:sup>, the neutral adduct [AlBr<jats:sub>3</jats:sub>(BuIm)], as well as the anions Br<jats:sup>−</jats:sup>, [AlBr<jats:sub>4</jats:sub>]<jats:sup>−</jats:sup>, and [Al<jats:sub>2</jats:sub>Br<jats:sub>7</jats:sub>]<jats:sup>−</jats:sup> could be identified as the products of the symmetric and asymmetric cleavage of dimeric Al<jats:sub>2</jats:sub>Br<jats:sub>6</jats:sub>. Furthermore, there are hints at the formation of [AlBr<jats:sub>2</jats:sub>(BuIm)<jats:sub>2</jats:sub>]<jats:sup>+</jats:sup> or related cations. Comparison of the AlBr<jats:sub>3</jats:sub>/BuIm system with AlCl<jats:sub>3</jats:sub>‐based mixtures revealed the influence of the halide: In contrast to AlBr<jats:sub>3</jats:sub>, the trication [Al(BuIm)<jats:sub>6</jats:sub>]<jats:sup>3+</jats:sup> could not be detected as main product in a 1:6 mixture of AlCl<jats:sub>3</jats:sub> and BuIm. Additionally, [AlCl<jats:sub>3</jats:sub>(BuIm)] crystallizes from a mixture with <jats:italic>x</jats:italic>(AlCl<jats:sub>3</jats:sub>)=0.60 at room temperature, whereas the corresponding AlBr<jats:sub>3</jats:sub>‐based mixture remains liquid even at +6 °C. Three AlBr<jats:sub>3</jats:sub>‐based mixtures are liquid at room temperature, whereas all other mixtures are solids with melting points between 46 and 184 °C. The three liquid mixtures exhibit medium to high viscosities (117 to >1440 mPa s), low conductivities (0.03–0.20 mS cm<jats:sup>−1</jats:sup>), but high densities (1.80–2.21 g cm<jats:sup>−3</jats:sup>). Aluminum could be successfully deposited from one of the neat Lewis acidic mixtures of the AlBr<jats:sub>3</jats:sub>‐based system.</jats:p>