Two new layered chalcogenide–chloridoaluminate compounds, Cu(Sb₂Se₃)[AlCl₄] and Cu₅(Bi₂Se₃)₆[AlCl₄]₅, were obtained by ionothermal synthesis from Lewis-acidic [BMIm]Cl/AlCl₃ melts at 200°C. Single-crystal X-ray diffraction shows that Cu(Sb₂Se₃)[AlCl₄] contains corrugated (Formula presented.) Cu(Sb₂Se₃)]⁺ layers in which an intrinsically two-dimensional Sb₂Se₃ net built from 12-membered rings is cross-linked by copper(I) atoms; [AlCl₄]⁻ anions separate the cationic sheets and provide a weak Cu.Cl coordination. Cu₅(Bi₂Se₃)₆[AlCl₄]₅ features terraced (Formula presented.) Cu₃(Bi₂Se₃)₆]³⁺ layers composed of (Formula presented.) Bi₂Se₃] ribbons that are connected by copper(I) atoms. The interlayer region comprises [AlCl₄]⁻ anions and [CuSeCl₃] tetrahedra. Density functional theory-based bonding analyses indicate highly polar Al.Cl and Cu.Cl interactions, more covalent Cu.Se bonding, and predominantly covalent Sb.Se and Bi.Se bonds. Electronic-structure calculations yield indirect band gaps of about 1.35 eV for Cu(Sb₂Se₃)[AlCl₄] and 0.40 eV for Cu₅(Bi₂Se₃)₆[AlCl₄]₅. Optically allowed direct transitions at slightly higher energies account for the broad absorption observed in the UV/Vis spectra. Treatment with dilute HCl partially extracts the chloridoaluminate components and promotes splitting along the layers, producing flake-like products, albeit with substantial loss of long-range order.