Using the ligands N-methylimidazole (MeIm), N-ethylimidazole (EtIm), N-propylimidazole (PrIm), and 1-methyl-1H-1, 2, 4-triazole (MeTz) three series with a total of 13 iron(II) complexes were isolated. The series comprise of the following complexes: (a) [Fe(MeIm)₆](ClO₄)₂ (1), [Fe(EtIm)₆](ClO₄)₂ (2), [Fe(PrIm)₆](ClO₄)₂(3), [Fe(MeTz)₆](ClO₄)₂ (4), [Fe(MeIm)₆](MeSO₃)₂ (5), [Fe(EtIm)₆](MeSO₃)₂ (6), and [Fe(MeTz)₆](BF₄)2 (10); (b) [Fe(MeIm)₄(MeSO3)2](7), [Fe(EtIm)₄(MeSO₃)₂] (8), and [Fe(PrIm)₄(MeSO₃)₂] (9); (c) [Fe(MeIm)4(NCS)₂] (15), [Fe(EtIm)₄(NCS)₂ ] (16), and [Fe(MeTz)₄(NCS)2] (17). Single crystal X-ray diffraction studies were performed on 7–10 and 15–17. Temperature dependent magnetic susceptibility measurements were performed on selective examples of all series, and confirmed them to be in the HS state over the range 6–300 K. DFT calculations were performed at BP86/def-SV(P) and TPSSh/def2-TZVPP level on all [FeL₆]²⁺ complex cations and the neutral complexes 7–9 and 15–17. Additionally the four homoleptic nickel(II) complexes [NiL₆](ClO₄)₂ (11: L = MeIm; 12: L = EtIm; 13: L = PrIm; 14: L = MeTz) were synthesized and compounds 11–13 structurally characterized. UV/Vis/NIR spectroscopic measurements were carried out on all homoleptic iron(II) and nickel(II) complexes. The 10Dq values were determined to be in the range of 11547–11574 and 10471–10834 cm⁻¹ for the iron(II) and nickel(II) complexes, respectively.