Three mononuclear spin crossover (SCO) compounds [Fe(2pic)(3)]center dot A2-Solv (A = m-ABS(-), Solv = MeOH, 1; A = p-ABS-, 2; A = OTf-, 3) were prepared and characterized magnetically and structurally (2-pic = 2picolylamine, m-HABS = m-aminobenzenesulfonic acid, p-HABS = paminobenzenesulfonic acid, HOTf = trifluoromethanesulfonic acid). Singlecrystal X-ray analyses show that they are constructed from the charge-assisted hydrogen bonds between the 2-pic donors and the organosulfonate acceptors, forming the hydrogen-bonded three-dimensional networks for 1 and 2 and one-dimensional columns for 3. While the [Fe(2-pic)3]2 cations in compounds 1 and 2 are in the meridional (mer-) configuration, it has a facial (fac-) configuration in complex 3. Magnetic susceptibility measurements revealed the SCO transitions and the SCO properties in all three complexes are quite different. Compound 1 undergoes an abrupt SCO with critical temperatures T1121, = 100 K and T112t = 103 K, while compound 2 exhibits a gradual SCO with T112 = 218 K Compound 3, with the fac-configuration, has an abrupt SCO transition accompanied by the structural phase transition with critical temperatures T112.1, = 333 K and T112t = 343 K. The SCO transitions were further confirmed by the detailed structural analyses of the coordination environments of the Fell centers in both spin states and also by differential scanning calorimetry. Compared to the famous [Fe(2-pic)(3)]-A2-Solv compounds in the literature, compound 2 has the highest transition temperature for the mer-[Fe(2-pic)(3)](2+)-containing compounds, while compound 3 represents the first example of the structurally characterized compound of the fac-[Fe(2-pic)(3)](2) motif showing SCO behavior. These results show that the organosulfonate anions are very promising to adjust the hydrogen-bonded structures of the SCO compounds and improve the SCO properties of those structures.