Insight into understanding magnetic transition quite sensitive to nonmagnetic impurity in a one-dimensional S = ½ regular linear chain system

Abstract

Herein, we demonstrate that the antiferromagnetic couplings in a [Ni(mnt)2]− stack are realized mainly through spatial dipole–dipole type interactions.

Structural, magnetic and phase transition properties in S = ½ radical solid solutions of [FxCl1−x-BzPy][Ni(mnt)2] (x = 0.07–0.87)

“…Most recently, we further investigated the crystal structures and magnetic properties of 1D solid solutions [CN-BzPy][Cu x Ni 1− x (mnt) 2 ] ( x = 0–1), and discovered that [CN-BzPy][Ni(mnt) 2 ] shows higher thermal stability than isomorphic but nonmagnetic [CN-BzPy][Cu(mnt) 2 ] owing to the magnetic couplings within an anion stack providing additional stabilization energy for the lattice formation. 41 On the basis of the above findings, we suppose that, around T C , the contribution of Coulomb interactions to the formation energy of the lattice is comparable, and however, the contribution of magnetic couplings to the formation energy of the lattice is significantly different for the HTP and the LTP in the [F x Cl 1− x -BzPy][Ni(mnt) 2 ] ( x = 0–1) crystals. Taking [F-BzPy][Ni(mnt) 2 ] as an example, the magnetic coupling energy is estimated to be ∼0.13 kJ mol −1 (= J / k B × 8.31 × 10 –3 kJ mol −1 ) in the HTP and ∼1.87 kJ mol −1 ( = Δ /(2 k B ) × 8.31 × 10 –3 kJ mol −1 ) in the LTP, and the magnetic coupling energy is close to the intermolecular van der Waals interaction energy (generally, less than 5 kJ mol −1 ) in the LTP, 42 but it is much higher than that in the HTP, and this leads to the crystal structure being more thermodynamically stable in the LTP than that in the HTP, and the lattice vibrations assist the transformation between the HTP and the LTP in [F-BzPy][Ni(mnt) 2 ], and this case is similar to that in the spin-Peierls transition.…”

“…Most recently, we further investigated the crystal structures and magnetic properties of 1D solid solutions [CN-BzPy][Cu x Ni 1−x (mnt) 2 ] (x = 0-1), and discovered that [CN-BzPy][Ni(mnt) 2 ] shows higher thermal stability than isomorphic but nonmagnetic [CN-BzPy][Cu(mnt) 2 ] owing to the magnetic couplings within an anion stack providing additional stabilization energy for the lattice formation. 41 On the basis of the above findings, we suppose that, around T C , the contribution of Coulomb interactions to the formation energy of the lattice is comparable, and however, the contribution of magnetic couplings to the formation energy of the lattice is significantly different for the HTP and the LTP in the…”

Halogen substitution effects on crystal structures and magnetic properties in nickel dithiolate molecular crystals

“…[1][2][3][4][5][6] These excellent physicochemical properties may be obtained through rational design and careful regulation. The chemical strategy for adopting functional properties mainly includes isotope substitution, 7,8 doping, [9][10][11] and introducing substituents. In many cases, we notice that halogen bonding becomes another essential driving force in crystal engineering to rationalize, orient, and control the solid-state structures and hence achieve well-defined functional materials.…”