Mössbauer effect of the alkaline and alkaline earth metal nitroprusside powders

We observe Mössbauer spectra of Fe atoms centered in nitroprusside anions of sodium nitroprusside (Na₂ [Fe(CN)₅NO] · 2H₂O), potassium-nitroprusside (K₂[Fe(CN)]₅NO · 2.5H₂O), rubidium nitroprusside (Rb₂[Fe(CN)₅NO] · H₂O), magnesium nitroprusside (Mg[Fe(CN)₅NO] · 5H₂O), calcium nitroprusside (Ca[Fe(CN)₅NO] · 4H₂O), and barium nitroprusside (Ba[Fe(CN)₅NO] ·3H₂O) samples which have photochromic properties. We compare the Mössbauer parameters, the values of the isomer shifts and the quadrupole splittings of the samples with those of a sodium nitroprusside single crystal which is a standard material. The values of the isomer shifts and the quadrupole splittings of the various compounds are close to each other. The values of the line broadening of all samples are between 2.1Γ _N and 2.5Γ_N. The Mössbauer Lamb factors (f) are between 0.252(1) and 0.340(2). These values are obtained from the slope of experimental line width as the masses of the samples are increased. Also, we investigate the structure of nitroprusside samples by X-ray diffraction and the N-O and the C-N bonding absorption lines in the nitroprusside anion by infrared experiments.