Cationic complexes of the type [Fe(L^NN)₃]²⁺ and [Fe(L^NNN)₂]²⁺ have been isolated as Cl^–, ClO₄^–, or BF₄^– salts, where L^NN and L^NNN represent bidentate and tridentate nitrogen-donor ligands respectively. The bidentate ligands were 2-(2′-pyridyl) benzimidazole (pybtim), 2-(2′-pyridyl)-N-methylbenzimidazole (mpybzim); 2-(2′-pyridyl) benzothiazole (pybzt), 2,2′-dipyridylamine (dpya), and the tridentates di(2-pyridylmethyl)amine (dpyma), 2,6-bis(benzimidazol-2′-yl)pyridine (bzimpy), 2,6-bis(N-methylbenzimidazol-2′-yl)pyridine (mbzimpy), and 2,6-bis(benzothiazol-2′-yl) pyridine (bztpy). Except for [Fe(dpya)₃][ClO₄]₂, all these FeN₆ chromophores exhibit strong absorption in the 550 nm region, which is assigned as a metal-to-ligand charge-transfer transition. Between 4 and 320 K, the iron(II) is in the low-spin form in the majority of these compounds; high-spin exceptions are [Fe(dpya)₃][ClO₄]₂ and [Fe(mbzimpy)₂]Cl₂. Other complexes show evidence of the onset of a spin transition near 40 °C, while the salt [Fe(bztpy)₂][ClO₄]₂·CHCl₃ is a well defined spin-crossover system. The low-spin complex [Fe(bzimpy)₂][ClO₄]₂ was excited by irradiation with visible light, and the generation and decay of the resulting high-spin form was observed under cryogenic conditions. In solution, [Fe(bzimpy)₂]²⁺ acts as a weak diprotic acid and also exhibits quintet ⇌ singlet spin crossover (ΔH^⊖=–42.7 kJ mol^–1, ΔS^⊖=–140.9 J K^–1 mol^–1). The complexes are all electrochemically oxidizable to their iron(III) forms in non-aqueous solution, but the dpyma, bztpy, pybtz, and dpya chelates thus formed are unstable. The iron(III) complex [Fe(H_–2bzimpy)₂]^– containing the doubly deprotonated ligand was obtained as its low-spin triethylammonium salt. The high-spin chloro complexes [Fe(bzimpy)Cl₃], [Fe(mbzimpy)Cl₃], Fe(mbzimpy)Cl₂, and the mixed-spin iron(II) complex salt [Fe(bzimpy)][FeCl₄] were also isolated.