Four mercury(II) thiocyanate–organic polymeric complexes, [Hg(μ-4,4-bipy)(SCN) 2 ] n (1), [Hg(μ-bpa)(SCN) 2 ] n (2), [Hg(μ-bpe)(SCN) 2 ] n (3), [Hg(μ-bpp)(SCN) 2 ] n (4) {4,4-bipy=4,4′-bipyridine, bpa=1,2-bis(4-pyridyl)ethane, bpe=1,2-bis(4-pyridyl)ethene and bpp=1,3-di(4-pyridyl)propane} were prepared from reactions of mercury(II) thiocyanate with four rigid and flexible organic nitrogen donor-based ligands under thermal gradient conditions, brunched tube method. All these compounds were structurally determined by X-ray single-crystal diffraction. The thermal stabilities of compounds 1–4 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Solid state luminescent spectra of compounds 1 and 3 indicate intense fluorescent emissions at 430 and 468nm, respectively.