Recent development of poly-NHCs reveals their potential application in constructing organic and organometallic polymers. In order to contribute to the field, we synthesized a series of planar trisimidazolium salts, the apparent precursor for tris(NHC)s, based on the triphenylene backbone. These imidazolium salts with D3h symmetry are prepared in moderate yield with various bulky N-substituents. Among these imidazolium salts, the t-butyl substituted free carbene (4b) was generated via deprotonation of [4b-H3]3+ with LDA. For the diphenylmethyl substituted one, [4a-H3]3+, a tris-thiourea derivative (4a-S3) isolated from the reaction of [4a-H3]3+, K2CO3, and S8 suggests the generation of the free carbene intermediate. Compound 4a-S3 can be further converted into poly-cationic disulfide salt with triflic anhydride, which acts as an oxidizing agent for thioureas. Reactions of [4a-H3]3+ and Ag2O or Hg(OAc)2 yield the polymeric Ag-NHC polymer and Hg-NHC polymer, respectively.