A family of 2,9-di(3-R-1H-imidazolium-1-yl)-1,10-phenanthroline iodides and hexafluorophosphates (R = allyl, benzyl, mesityl, picolyl) were synthesized from 2,9-diiodophenanthroline and imidazole or N-substituted imidazoles. Simple reactions of these diimidazolium salts with copper powder at room temperature have afforded a series of multinuclear copper(I)-NHC complexes in good yields. The structures vary depending on the N substituents and counterions. [Cu-4(L1)(2)(MeCN)(4)](PF6)(4) (R = allyl) exhibits a zigzag Cu-4 chain with two terminal [Cu(NHC)(MeCN)(2)] and two internal [Cu(phen)-(NHC)] moieties. [Cu-3(L-2)(2)](PF6)(3) (R = benzyl) contains a strictly linear Cu-3 framework with two [Cu(NHC)(2)] units and a [Cu(phen)(2)] located at the center. Both complexes [Cu-3(L-4)(2)](PF6)(3) (R = mesityl) and [Cu-3(L5)(2))(PF6)(3) (R = picoly1) consist of a triangular Cu3 core in which two copper(I) ions are surrounded by a phen and a NHC group and the third copper(I) is coordinated by two NHC groups. [Cu-3(L-3)(2)](PF6)(3) derived from 2,9-di(3-benzyl-1H-benzimidazolium-1-yl)-1,10-phenanthroline hexafluorophosphate can undergo transannulation of the benzimidazolylidene ring giving [Cu-2(L3')(2)](PF6)(2). The decomposition process might involve solvent-induced rearrangement of the ligand and hydrolysis of carbene moieties. Treatment of 2,9-di(3-mesityl-1H-benzimidazolium-1-yl)-1,10-phenanthroline iodide with copper powder generated dinuclear complex [Cu-2(L4)(2)][Cu-2(mu-I)(2)I-2] (R = mesityl) possessing a macrocyclic cation and [Cu-2(mu-I)(2)I-2](2-) anion. Tetranuclear complex [Cu-4(L5)(2)(mu-I](2)](CuI3) (R = picolyl) has been obtained from its diimidazolium iodide and copper powder. All Cu(I) complexes have been characterized by X-ray single diffraction analysis, elemental analysis, and NMR spectra. Their redox behavior and fluorescent properties have also been studied.