Two imidazolium salts containing one or two pentadodecyloxytriphenylene units linked through a hexyloxy chain and Br-, [AuBrmCl4-m](-), or [PtBrmCl4-(m)](2-) (m = 0-3) as counterion have been prepared. Reaction of the imidazolium bromides with M2O (M = Cu, Ag), or carbene transmetalation from the silver product, leads to N-heterocyclic carbene complexes [MX(NHC)] (M = Cu, X = Br; M = Au, X = Cl, C equivalent to CPh), [Ag(NHC)(2)][AgBr2], and [PtCl2(NHC)(2)], with NHC bearing one or two triphenylene fragments. Except for the gold derivatives and one Cu complex, the rest of them behave as liquid crystals organized in columnar mesophases (rectangular c2mm or p2mg or hexagonal p6mm symmetries) with melting points in the range 30 to 60 degrees C and clearing points in the range 57-112 degrees C. The mesophase structures were determined by small-angle X-ray scattering. Structural studies and models point to nanosegregation of triphenylene columns and imidazolium/metal carbene moieties, separated by alkoxy chains, leading to multicolumnar systems. The compounds display emission spectra related to the triphenylene core in solution, in the mesophase, in the isotropic liquid, and in the solid state.