Hydrothermal recrystallization of transition metal nitroprussides. Formation of the most stable phases

Thermally Induced Spin Transition in a 2D Ferrous Nitroprusside

“…When the low temperature region of the magnetization curve is considered in detail, that fraction appears involved in an anti‐ferromagnetic interaction is appreciated with a Curie–Weiss temperature of –14.5 K (Figure , Inset). This CW value is quite similar to the one found for 3D ferrous nitroprusside, and corresponds to the expected weak interaction between equal spin bearing centers, Fe(2+) atoms, at a distance of about 10 Å. From the value of χT in the high temperature paramagnetic region, an effective magnetic moment ( µ eff ) of 5.32 µB was obtained, which is in the expected range for an spin only magnetic interaction from iron(2+) ions…”

“…Since the formation of the layered solid can be described as the selective rupture of the axial metal–NC bond in a 3D metal nitroprusside, as initial structural model to be refined, the crystal structure reported for the 3D phase of ferrous nitroprusside was used …”

“…Transition metal (T) nitroprussides, T[Fe(CN) 5 NO], are usually obtained as 3D solids, and only recently the preparation of their 2D analogues has been reported , . Such spin transition is not observed for 3D ferrous nitroprusside …”

Thermally induced spin-crossover in the Fe(3-ethynylpyridine)2[M(CN)4] series with M = Ni, Pd, and Pt. The role of the electron density found at the CN 5σ orbital

“…This post-synthesis treatment has proved to be appropriate for obtaining the thermodynamic product for the case of transition metal hexacyanometallates and nitroprussides. [39][40][41][42] No structural modifications were found in the materials after the solvothermal treatment. The obtained materials were analyzed in terms of their nature and purity, from chemical analysis (ICP and CHONS), XRD, TG, IR, and Raman data.…”

“…This information is complemented by structural studies from XRD powder patterns and periodic DFT calculations using the VASP package. [38][39][40][41] The dependence of the spin transition temperature on the inner metal (Ni, Pd, and Pt) is discussed in terms of the electron density accumulated, via p-back donation, at the CN 5s orbital. This is supported by N1s core-level binding energy obtained from XPS spectra.…”