Crystal structure of room-temperature ionic liquid 1-butyl-isoquinolinium gallium tetrachloride [(BIQL)GaCl4]

The crystal structure of 1-butyl-isoquinolinium gallium tetrachloride [(BIQL)GaCl4], which forms room-temperature ionic liquids, has been determined by X-ray diffraction of its single crystal at 113 K. The title crystal belongs to the monoclinic system space group P21/c with a = 7.1438(12) Å, b = 14.3490(14) Å, c = 16.3531(18) Å, β = 94.885(7)°, V = 1670.2(4) Å3 for Z = 4 and FW = 397.81, μ = 0.124 mm−1, F(000) = 800, Dc = 1.582 mg m−3, R = 0.0266 and wR = 0.0606 for 4068 observed reflections (I > 2.00σ(I)). The ionic liquid of (BIQL)GaCl4 has lamellar structure as mainly π electron plane of isoquinoline interleave and the layer distance is 3.431 Å connected with GaCl4− structure size. The cation and anion of (BIQL)GaCl4 arrange orderly in pair and the results indicate that coulombic attraction is dominant, although weak local hydrogen bonds (C–H⋯Cl) exist simultaneously.