The preparation of binuclear mesogenic copper(I) isocyanide complexes [CuX(CNR)(2)](2) (X = halogen; R = C6H4C6H4-OC10H21 (L-A), C6H4COOC6H4OCnH2n+1 (L-B), C6H2(3,4,5-OCnH2n+1)(3) (L-C)) with an unusual tetrahedral core is described. The copper complexes with L-A are not liquid crystals, but the Cu-L-B complexes show SmA mesophases and the Cu-L-C derivatives display hexagonal columnar mesophases, some of them at room temperature. The relationship between the molecular structure of the complexes and their thermal behavior is discussed.