The Fe Mössbauer experiments were performed on the polycrystalline sample of 1 at 14, 30, 100, 170, and 300 K to confirm the presence of LS and HS states, and consistently the spin state switching and symmetry breaking in 1. Figure and Table show the Mössbauer spectra and spectral parameters, respectively. At 14 K, the spectrum shows two doublets, one doublet with the value of the isomer shift () and smaller quadrupole splitting (ΔEQ) lying in the range expected for LS Fe(II), and another less intense doublet with the value of δ and larger ΔEQ lying in the range expected for HS Fe(II). The spectral area of the LS and HS Fe(II) doublet are 96% and 4% respeectively, which is consistent with the magnetic measurement (Table ). Upon increasing the temperature proportion of the HS Fe(II) state increases with deceasing proportion of the LS Fe(II) state which is reflected in the spectral area (Table ). At 170 K, the spectral area of the LS and HS Fe(II) doublet becomes 65% and 35% respectively, consistent with the magnetic and structural analyses, and confirms the presence of an intermediate HS:LS Fe(II) state. Upon further increasing the temperature to 300 K, the spectrum shows only one doublet for the HS Fe(II) state, which is consistent with the magnetic and crystal structure analysis data.